CN1113463C - Tuning control manner - Google Patents

Tuning control manner Download PDF

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CN1113463C
CN1113463C CN96198160A CN96198160A CN1113463C CN 1113463 C CN1113463 C CN 1113463C CN 96198160 A CN96198160 A CN 96198160A CN 96198160 A CN96198160 A CN 96198160A CN 1113463 C CN1113463 C CN 1113463C
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mentioned
circuit
phase
signal
tuning
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CN1201568A (en
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池田毅
大江忠孝
冈本明
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/06—Arrangements for obtaining constant bandwidth or gain throughout tuning range or ranges
    • H03J3/08—Arrangements for obtaining constant bandwidth or gain throughout tuning range or ranges by varying a second parameter simultaneously with the tuning, e.g. coupling bandpass filter

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  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)

Abstract

A tuning mechanism is provided with a tuning circuit 1 and a frequency control circuit 2 incorporating a synchronous rectifying circuit 3, a pulse converting circuit 5, a polarity judging circuit 6, and a voltage generating circuit 7. The circuit 3 rectifies the input signal of the circuit 1 synchronously with the output of the circuit 1 and the circuit 5 outputs a signal having a pulse width corresponding to the deviation(phase difference) of the frequency of the input signal from the tuning frequency based on the synchronous rectification output. The circuit 6 judges the polarity of the phase difference and the circuit 7 generates a control voltage to be applied to the circuit 1 by combining the voltage corresponding to the pulse outputted from the circuit 5 with a prescribed voltage according to the judged polarity of the phase difference. The circuit 1 equalizes the tuning frequency to the frequency of the input signal of the circuit 1 based on the control voltage from the circuit 2.

Description

Tuning control manner
Technical field
The tuning control manner that the present invention relates to only to make the frequency signal of regulation to pass through.
Background technology
It is well-known having used the filter and the tuning circuit of the various structures of LC resonance etc.For example, the intermediate frequency amplifier circuit of superheterodyne receiver just has the function as filter, and in general, existing intermediate frequency amplifier circuit realizes the frequency characteristic of expection by adopting many group intermediate frequency transformers (IFT) and capacitor.For example, under the situation of AM receiver, centre frequency is set at 455kHz, is set at the ormal weight of when from this centre frequency imbalance 9kHz, only decaying simultaneously.In addition, the also known AM receivers that the frequency characteristic of using a realization expection such as the many groups of ceramic filter replacement intermediate frequency transformers is arranged.
; in the prior art that adopts above-mentioned superhet mode; owing in carrying out the structure that tuning filter is an intermediate frequency amplifier circuit, comprise intermediate frequency transformer or ceramic filter, so it is very difficult that the integral body that will comprise these parts is carried out integrated on Semiconductor substrate.
In addition, with the local oscillator circuit of this intermediate frequency amplifier circuit combination, if simple then by the LC oscillator realization of employing local oscillation transformer, high-precision as if constituting then by the PLL structure realization of adopting crystal oscillation.When particularly adopting local oscillator circuit as the PLL structure, because of comprise the voltage-controlled type oscillator (VCO) that carries out sine-wave oscillation be difficult to integrated, so in a part of circuit, adopted mixing IC.
Therefore, as one overall, not only comprise the intermediate frequency amplifier circuit of working, even also comprising the local oscillator circuit that constitutes mechanical tuning device with its combination as filter, thereby be difficult to integratedly, a kind ofly can make the whole integrated tuning control manner of mechanical tuning device so expecting to have.In addition, though the whole of the filter that in the past existed or the integral body that comprises the circuit of this filter have been realized integrated, but owing in circuit parameter, produce very big discrete discrepancy, so the characteristic of every chip block of making is all inequality.In addition, also to consider centre frequency with situations that great changes will take place such as temperature, so, a kind of tuning control manner that still can reach desired frequency characteristics after integrated is not reliably also proposed up to now.
Disclosure of an invention
The present invention proposes for solving above-mentioned problem, and its objective is provides a kind of integrated new tuning control manner that is applicable to.
Tuning control manner of the present invention has: tuning circuit, comprise wildcard-filter style phase-shift circuit that 2 cascades connect, and the output of above-mentioned phase-shift circuit that will the back level feed back to the input side of the above-mentioned phase-shift circuit of prime as feedback signal, to be input to the add circuit of the above-mentioned phase-shift circuit of prime after above-mentioned feedback signal and the input signal addition simultaneously, and the signal near assigned frequency is passed through; And frequency control circuit, when above-mentioned tuning circuit having been imported the signal of the close afore mentioned rules frequency of its frequency, according to the phase difference between the input/output signal of above-mentioned tuning circuit, make the tuned frequency of above-mentioned tuning circuit consistent with the frequency of the input signal of above-mentioned tuning circuit.
So, there is not phase difference between the input/output signal that makes tuning circuit by controlling, can make tuned frequency follow the tracks of the frequency of input signal all the time and be consistent.
The simple declaration of accompanying drawing
Fig. 1 is the figure of expression as the structure of the mechanical tuning device of an example that has adopted tuning control manner of the present invention.
Fig. 2 is the figure of the detailed structure of expression tuning circuit.
Fig. 3 is the circuit diagram that illustrates after the structure of prime phase-shift circuit shown in Figure 2 is extracted out.
Fig. 4 is the input and output voltage of expression phase-shift circuit shown in Figure 3 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Fig. 5 is the circuit diagram that illustrates after the structure of back level phase-shift circuit shown in Figure 2 is extracted out.
Fig. 6 is the input and output voltage of expression phase-shift circuit shown in Figure 5 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Fig. 7 is that the integral replacement with 2 phase-shift circuits shown in Figure 2 and bleeder circuit is the circuit diagram that has behind the circuit of transfer function K1.
Fig. 8 carries out circuit diagram after the conversion according to the Miller theorem to circuit shown in Figure 7.
Fig. 9 is the figure of the tuning characteristic of expression tuning circuit shown in Figure 2.
Figure 10 is the figure of phase relation between the input/output signal of 2 phase-shift circuits of expression.
Figure 11 is the figure of the phase relation between the input/output signal of expression tuned frequency each phase-shift circuit when being higher than the signal frequency that is input to the prime phase-shift circuit.
Figure 12 is the figure of the phase relation between the input/output signal of expression tuned frequency each phase-shift circuit when being lower than the signal frequency that is input to the prime phase-shift circuit.
Figure 13 is the circuit diagram of expression frequency control circuit detailed structure.
Figure 14 is the time diagram of tuned frequency when being higher than the signal frequency that is input to tuning circuit of expression tuning circuit.
Figure 15 is the time diagram of tuned frequency when being lower than the signal frequency that is input to tuning circuit of expression tuning circuit.
Figure 16 is the figure of structure of the mechanical tuning device of expression double as AM detection.
Figure 17 is the circuit diagram of the detailed structure of expression frequency control circuit shown in Figure 16.
Figure 18 is the figure that the AM receiver structure of mechanical tuning device shown in Figure 16 has been adopted in expression.
Figure 19 is the figure of structure of the mechanical tuning device of expression double as FM detection.
Figure 20 is the circuit diagram of the detailed structure of expression frequency control circuit shown in Figure 19.
Figure 21 is the figure of another structure example of expression frequency control circuit.
Figure 22 is the time diagram of the tuned frequency of expression tuning circuit when being higher than the frequency of the signal that is input to tuning circuit shown in Figure 21.
Figure 23 is the time diagram of the tuned frequency of expression tuning circuit when being lower than the frequency of the signal that is input to tuning circuit shown in Figure 21.
Figure 24 is the figure of another structure example of expression frequency control circuit.
Figure 25 is the time diagram of the tuned frequency of expression tuning circuit when being higher than the frequency of the signal that is input to tuning circuit shown in Figure 24.
Figure 26 is the time diagram of the tuned frequency of expression tuning circuit when being lower than the frequency of the signal that is input to tuning circuit shown in Figure 24.
Figure 27 is the figure of another structure example of expression frequency control circuit.
Figure 28 is the time diagram of the tuned frequency of expression tuning circuit when being higher than the frequency of the signal that is input to tuning circuit shown in Figure 27.
Figure 29 is the time diagram of the tuned frequency of expression tuning circuit when being lower than the frequency of the signal that is input to tuning circuit shown in Figure 27.
Figure 30 is the circuit diagram that expression comprises the phase-shift circuit structure of LR circuit.
Figure 31 is the input and output voltage of expression phase-shift circuit shown in Figure 30 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Figure 32 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 33 is the input and output voltage of expression phase-shift circuit shown in Figure 32 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Figure 34 is the circuit diagram of the 2nd variation of expression tuning circuit.
Figure 35 is the circuit diagram that expression comprises the phase-shift circuit structure of LR circuit.
Figure 36 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 37 is the circuit diagram of the 4th variation of expression tuning circuit.
Figure 38 is the circuit diagram of the 5th variation of expression tuning circuit.
Figure 39 is the circuit diagram of the 6th variation of expression tuning circuit.
Figure 40 is the circuit diagram of the 7th variation of expression tuning circuit.
Figure 41 is the circuit diagram of the 8th variation of expression tuning circuit.
Figure 42 is the circuit diagram that illustrates after the structure of prime phase-shift circuit shown in Figure 41 is extracted out.
Figure 43 is the input and output voltage of expression phase-shift circuit shown in Figure 42 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Figure 44 is the circuit diagram that illustrates after the structure of back level phase-shift circuit shown in Figure 41 is extracted out.
Figure 45 represents the input and output voltage of phase-shift circuit shown in Figure 44 and appears at the polar plot of the relation between the voltage on capacitor etc.
Figure 46 is the circuit diagram of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 47 is the input and output voltage of expression phase-shift circuit shown in Figure 46 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Figure 48 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 49 is the input and output voltage of expression phase-shift circuit shown in Figure 48 and the polar plot that appears at the relation between the voltage on the capacitor etc.
Figure 50 is the circuit diagram of the 10th variation of expression tuning circuit.
Figure 51 is the circuit diagram of the 11st variation of expression tuning circuit.
Figure 52 is the circuit diagram of the 12nd variation of expression tuning circuit.
Figure 53 is the circuit diagram that illustrates after the structure of the prime phase-shift circuit shown in Figure 52 is extracted out.
Figure 54 represents the input and output voltage of phase-shift circuit shown in Figure 53 and appears at the polar plot of the relation between the voltage on capacitor etc.
Figure 55 is the circuit diagram that illustrates after the structure of the back level phase-shift circuit shown in Figure 52 is extracted out.
Figure 56 represents the input and output voltage of phase-shift circuit shown in Figure 55 and appears at the polar plot of the relation between the voltage on capacitor etc.
Figure 57 is the circuit diagram of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 58 is the input and output voltage of phase-shift circuit shown in expression Figure 57 and the polar plot that appears at the relation between the voltage on the inductor etc.
Figure 59 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit.
Figure 60 is the input and output voltage of phase-shift circuit shown in expression Figure 59 and the polar plot that appears at the relation between the voltage on the inductor etc.
Figure 61 is the circuit diagram of the 14th variation of expression tuning circuit.
Figure 62 is the circuit diagram of the 15th variation of expression tuning circuit.
Figure 63 is the circuit diagram that forms the variable-resistance tuning circuit in the phase-shift circuit shown in Figure 3 with MOS type FET.
Figure 64 is the circuit diagram of the example when representing employing FET element in addition as the variable resistor in the phase-shift circuit.
Figure 65 moves phase-shift circuit the circuit diagram that illustrates after needed part is extracted out in the structure of operational amplifier.
The optimal morphology that is used to carry out an invention
Below, specifically describe an example of tuning control manner of the present invention with reference to accompanying drawing.
[integral body of A. mechanical tuning device constitutes and action]
Tuning control manner of the present invention is characterised in that: when the sine wave signal with certain frequency is input to tuning circuit, detect the phase difference between the input and output of tuning circuit, and control and make tuned frequency consistent with the frequency of input signal.
Fig. 1 is the figure of expression as the structure of the mechanical tuning device of an example that has adopted tuning control manner of the present invention.
Mechanical tuning device shown in this figure comprises: tuning circuit 1, play the effect that makes the filter that the signal near certain frequency passes through; And frequency control circuit 2, the center of this tuning circuit 1 is controlled by frequency.
Tuning circuit 1, comprise 2 phase-shift circuits as described later, when the output of back level phase-shift circuit is taken out as the output of tuning circuit 1, this signal is fed back by feedback resistance, will be by the input signal of input resistance input and feedback signal addition by the feedback resistance feedback, and be input to the prime phase-shift circuit.By means of above structure, the phase-shift phase that 2 phase-shift circuits are lumped together is set at 360 ° on the frequency of regulation.
In addition, tuning circuit 1 can be according to from the control signal of outside input tuned frequency being set arbitrarily in certain scope.About the detailed structure of tuning circuit 1 and action in detail, will illustrate below.
When the input signal of tuning circuit 1 and output signal are input to phase difference between frequency control circuit 2 and this input/output signal when departing from 360 °, when promptly there is deviation in the tuned frequency of the frequency of the component that passes through of wanting in input signal and tuning circuit 1, tuned frequency to tuning circuit 1 is controlled, and this deviation is equalled zero.
For carrying out this control, frequency control circuit 2 structurally comprises circuit of synchronous rectification 3 and control signal generative circuit 4.
Circuit of synchronous rectification 3 as contrast signal, carries out synchronous rectification to the input signal of tuning circuit 1 with the output signal of tuning circuit 1.Output after the synchronous rectification is imported into the control signal generative circuit 4 of back level.For example, if consider situation to tuning circuit 1 input single-frequency signals, when then the phase difference between thereby the input/output signal consistent with tuned frequency is 360 ° when the frequency input signal of tuning circuit 1, export half wave rectification wave voltage completely from above-mentioned circuit of synchronous rectification 3, when departing from 360 °, export the voltage suitable with this deviation.
Control signal generative circuit 4, structurally comprise pulse conversion circuit 5, polarity discriminating circuit 6 and voltage combiner circuit 7, be used to detect the phase error between the input/output signal of above-mentioned tuning circuit 1, differentiate the size and the polarity of this error simultaneously, and generation makes the null control signal of error.
The corresponding pulse train of the time interval that pulse conversion circuit 5 its pulse durations of output and the component of voltage of exporting from circuit of synchronous rectification 3 suitable with deviation occur.Polarity discriminating circuit 6, according to the component of voltage suitable from circuit of synchronous rectification 3 output with deviation be occur before the half wave rectification wave or after the polarity of differentiation phase error appears.The polarity of this error represents that tuned frequency is lower than or is higher than the frequency of input signal (saying exactly, is the frequency of the signal that takes out by tuning circuit 1 relatively) from input signal.
Voltage combiner circuit 7, be used to produce and the corresponding voltage of pulse duration from the signal of pulse conversion circuit 5 outputs, simultaneously, polarity according to the phase error of judging by polarity discriminating circuit 6, execution is synthetic to the voltage that the voltage of this generation carries out addition or subtraction, and the voltage after will synthesizing as control signal to tuning circuit 1 output.
In addition, constitute the circuit of synchronous rectification 3 of said frequencies control circuit 2 and the more detailed structure and the action of control signal generative circuit 4, will illustrate below.
[detailed structure of B. tuning circuit 1 and action]
Below, the tuning circuit shown in Fig. 11 is elaborated.Fig. 2 is the circuit diagram of the detailed structure of expression tuning circuit 1.Tuning circuit 1 shown in this figure structurally comprises: 2 phase- shift circuit 110C, 130C respectively with the phase shifts ormal weight of the AC signal imported, thereby add up to 360 ° phase shift under the frequency of regulation; Bleeder circuit 160, the resistance 162 and 164 of the outlet side of level phase-shift circuit 130C constitutes by being located at afterwards; And add circuit, will be respectively by feedback resistance 170 and input resistance 174 (resistance value of supposition input resistance 174 be feedback resistance 170 resistance value n doubly) the dividing potential drop output (feedback signal) of bleeder circuit 160 and signal (input signal) addition of importing at input terminal 190 to scale.
Fig. 3 is the circuit diagram that illustrates after the structure of prime phase-shift circuit 110C shown in Figure 2 is extracted out.Prime phase-shift circuit 110C shown in this figure structurally comprises: operational amplifier 112 is a kind of differential amplifiers; Variable resistor 116 and capacitor 114 will be input to the in-phase input terminal of operational amplifier 112 behind the phase shifts ormal weight of the AC signal of input on the input 122; Resistance 118 is plugged between the reversed input terminal of input 122 and operational amplifier 112; Resistance 121 and 123 is connected with the lead-out terminal of operational amplifier 112, and constitutes bleeder circuit; And resistance 120, be connected between the reversed input terminal of the lead-out terminal of this bleeder circuit and operational amplifier 112.
In having the phase-shift circuit 110C of said structure, resistance 118 is set at identical resistance value with resistance 120.In addition, can be according to the resistance value that changes variable resistor 116 from the control voltage of outside, for example, as shown in Figure 3, as resistive element, and the control voltage that will supply with from the outside is applied on the grid by control terminal shown in Figure 2 194 with the raceway groove of FET, thereby can carry out the setting of resistance value.
When importing the AC signal of regulation on input terminal shown in Figure 3 122, the voltage VR1 that will occur at the two ends of variable resistor 116 put on the in-phase input terminal of operational amplifier 112.And occur at the two ends of resistance 118 and the identical voltage VC1 of voltage VC1 in the appearance of the two ends of capacitor 114.On 2 resistance 118,120, flow through identical electric current I, and, as mentioned above, because each resistance value of resistance 118 and resistance 120 is equal, so voltage VC1 also occurs at the two ends of resistance 120.As considering that the reversed input terminal (VR1) with operational amplifier 112 is a benchmark, after then the both end voltage VC1 of resistance 118 being carried out vector addition, can get input voltage Ei, the both end voltage VC1 of resistance 120 is carried out after vector subtracts each other, can get voltage (dividing potential drop output) Eo ' of resistance 121 and the tie point of resistance 123.
Fig. 4 is the input and output voltage of expression prime phase-shift circuit 110C and the polar plot that appears at the relation between the voltage on the capacitor etc.
As mentioned above, as considering that the voltage VR1 with the in-phase input terminal that puts on operational amplifier 112 is a benchmark, then input voltage Ei is just different to the synthetic direction of voltage VC1 with branch pressure voltage Eo ', and its absolute value is equal.Hence one can see that, the size of input voltage Ei and branch pressure voltage Eo ' and the relation of phase place, can with input voltage Ei and branch pressure voltage Eo ' as hypotenuse, 2 times of isosceles triangles as the base of voltage VC1 are represented, the amplitude of branch pressure voltage Eo ' equate with the amplitude of input signal and and frequency-independent, phase-shift phase is represented with the shown in Fig. 41.This phase-shift phase 1 is a benchmark with input voltage Ei, changes to 360 ° along hour hands rotation direction (phase delay direction) from 180 ° according to frequency.
In addition, the output 124 of phase-shift circuit 110C is connecting the lead-out terminal of operational amplifier 112, so, as the resistance value of supposing resistance 121 is that the resistance value of R21, resistance 123 is R23, then compare with the resistance value of resistance 120 very hour as R21 and R23, between output voltage Eo and above-mentioned branch pressure voltage Eo ', have the relation of Eo=(1+R21/R23) Eo '.Therefore, by adjusting the value of R21 and R23, can obtain gain, and as shown in Figure 4, even frequency shift, it is constant that the amplitude of output voltage Eo can keep, only its phase shifts ormal weight greater than 1.
Equally, Fig. 5 is the circuit diagram that illustrates after the structure of back level phase-shift circuit shown in Figure 2 is extracted out.Back level phase-shift circuit 130C shown in this figure, structurally comprise: operational amplifier 132 is a kind of differential amplifiers; Capacitor 134 and resistance 136 will be input to the in-phase input terminal of operational amplifier 132 behind the phase shifts ormal weight of the signal that input 142 is imported; Resistance 138 is plugged between the reversed input terminal of input 142 and operational amplifier 132; Resistance 141 and 143 is connected with the lead-out terminal of operational amplifier 132, and constitutes bleeder circuit; And resistance 140, be connected between the reversed input terminal of the lead-out terminal of this bleeder circuit and operational amplifier 132.
In having the phase-shift circuit 130C of said structure, resistance 138 is set at identical resistance value with resistance 140.
When importing the AC signal of regulation on input terminal shown in Figure 5 142, the voltage VC2 that will occur at the two ends of capacitor 134 put on the in-phase input terminal of operational amplifier 132.And occur at the two ends of resistance 138 and the identical voltage VR2 of voltage VR2 in the appearance of the two ends of resistance 136.On 2 resistance 138, resistance 140, flow through identical electric current I, and, as mentioned above, because the resistance value of resistance 138 and resistance 140 is equal, so voltage VR2 also occurs at the two ends of resistance 140.As considering that the reversed input terminal (VC2) with operational amplifier 132 is a benchmark, after then the both end voltage VR2 of resistance 138 being carried out vector addition, can get input voltage Ei, the both end voltage VR2 of resistance 140 is carried out after vector subtracts each other, can get voltage (dividing potential drop output) Eo ' of resistance 41 and the tie point of resistance 43.
Fig. 6 is the input and output voltage of expression back level phase-shift circuit 130C and the polar plot that appears at the relation between the voltage on the capacitor etc.
As mentioned above, as considering that the voltage VC2 with the in-phase input terminal that puts on operational amplifier 132 is a benchmark, then input voltage Ei is just different to the compound direction of voltage VR2 with branch pressure voltage Eo ', and its absolute value is equal.Hence one can see that, the size of input voltage Ei and branch pressure voltage Eo ' and the relation of phase place, can with input voltage Ei and branch pressure voltage Eo ' as hypotenuse, 2 times of isosceles triangles as the base of voltage VR2 are represented, the amplitude of branch pressure voltage Eo ' equate with the amplitude of input signal and and frequency-independent, phase-shift phase is represented with the shown in Fig. 62.This phase-shift phase 2 is a benchmark with input voltage Ei, along with frequency changes to 180 ° along the hour hands rotation direction from 0 °.
In addition, the output 144 of phase-shift circuit 130C is connecting the lead-out terminal of operational amplifier 132, so, as the resistance value of supposing resistance 141 is that the resistance value of R41, resistance 143 is R43, then compare with the resistance value of resistance 140 very hour as R41 and R43, between output voltage Eo and above-mentioned branch pressure voltage Eo ', have the relation of Eo=(1+R41/R43) Eo '.Therefore, by adjusting the value of R41 and R43, can obtain gain, and as shown in Figure 6, even frequency shift, it is constant that the amplitude of output voltage Eo can keep, only its phase shifts ormal weight greater than 1.
In this manner, respectively with the phase shifts ormal weight, and as Fig. 4 and shown in Figure 6, under assigned frequency, the phase-shift phase in tuning circuit 1 overall is 360 ° in 2 phase- shift circuit 110C, 130C.
In addition, the output of back level phase-shift circuit 130C as shown in Figure 2, is taken out as the output of tuning circuit 1 from lead-out terminal 192, simultaneously, the output that makes this phase-shift circuit 130C is fed back to the input side of prime phase-shift circuit 110C via feedback resistance 170 by the signal of bleeder circuit 160.Then, with this feedback signal and signal plus, and the signal after this addition is input to prime phase-shift circuit 110C by input resistance 174 input.
Like this, the phase-shift phase that under assigned frequency, produces by 2 phase- shift circuit 110C, 130C, add up to 360 °, at this moment, loop gain by the feedback loop that will be made of 2 phase- shift circuit 110C, 130C, bleeder circuit 160 and feedback resistance 170 is set in below 1, the tuning action that the signal of afore mentioned rules frequency component is passed through.
In addition, what take out from the lead-out terminal 192 of tuning circuit 1 is the output that is input to the phase-shift circuit 130C before the bleeder circuit 160, so, the gain that can keep tuning circuit itself, thus can be when carrying out tuning action with the amplitude amplification of signal.
Fig. 7 is the circuit diagram that will have behind 2 phase- shift circuit 110C, 130C of said structure and the circuit that bleeder circuit 160 integral replacements become to have transfer function K1, the feedback resistance with resistance R 0 170 in parallel with the circuit with transfer function K1 is connected in series with input resistance 174, and the resistance value of this input resistance 174 is n times (nR0) of feedback resistance 170.
Fig. 8 carries out circuit diagram after the conversion according to the Miller theorem to circuit shown in Figure 7, and the transfer function A of the whole system after the conversion can represent with following formula:
A＝Vo/Vi＝K1/{n(1-K1)+1}…(1)
The time constant of the CR circuit that is made of variable resistor 116 and capacitor 114 as supposition is T 1(as the resistance value of establishing variable resistor 116 is that the electrostatic capacitance of R, capacitor 114 is C, then T 1=CR), then the transfer function K2 of prime phase-shift circuit 110C is
K2＝-a 1(1-T 1s)/(1+T 1s) …(2)
In the formula, s=j ω, a 1Be the gain of phase-shift circuit 110C, i.e. a 1=(1+R21/R23)＞1.
In addition, be T as the time constant of supposing the CR circuit that constitutes by capacitor 34 and resistance 36 2(as the electrostatic capacitance of establishing capacitor 34 is that the resistance value of C, resistance 36 is R, then T 2=CR), then the transfer function K3 of prime phase-shift circuit 110C is
K3＝a 2(1-T 2s)/(1+T 2s)…(3)
In the formula, a 2Be the gain of phase-shift circuit 130C, i.e. a 2=(1+R41/R43)＞1.
Decay to 1/a as supposition by bleeder circuit 160 back signal amplitudes 1a 2, the overall transfer function K1 when then just 2 phase- shift circuit 110C, 130C are connected with bleeder circuit 160 cascades is
K1＝-{1+(Ts) 2-2Ts}/{1+(Ts) 2+2Ts}…(4)
And in above-mentioned formula (4), calculate for simplifying, with the time constant T of each phase-shift circuit 1, T 2All be assumed to T.As with the above-mentioned formula of this formula (4) substitution (1), can get
A＝-{1+(Ts) 2-2Ts}/[(2n+1){1+(Ts) 2}+2Ts]
＝-{1/(2n+1)}[{1+(Ts) 2-2Ts}/{1+(Ts) 2+2Ts/(2n+1)}]
…(5)
From this formula (5) as can be known, when ω=0 (direct current zone), A=-1/ (2n+1) can provide maximum attenuation.And when ω=∞, also equal A=-1/ (2n+1), maximum attenuation also can be provided as can be known.It can also be seen that, the tuning point of ω=1/T (under the different situation of the time constant of each phase-shift circuit, ω = 1 / ( T 1 · T 2 ) Tuning point) on, A=1, thereby irrelevant with the resistance ratio n of feedback resistance 170 and input resistance 174.In other words, as shown in Figure 9, even the value of n changes, tuning point also can not be offset and the attenuation of tuning point can not change yet.
And, by changing the resistance value of the variable resistor 116 in the prime phase-shift circuit 110C, can change the time constant of the CR circuit that phase-shift circuit 110C comprised, and can change tuned frequency ω within the specific limits arbitrarily.
; in above-mentioned Fig. 7; when all pass circuit of representing with transfer function K1 has input impedance, form bleeder circuit by the input impedance of feedback resistance 170 and this all pass circuit, will be so comprise the loop gain of the feedback loop of all pass circuit less than the absolute value of transfer function K1.The input impedance of so-called all pass circuit, be the input impedance of prime phase-shift circuit 110C, the also input resistance 118 of the series impedance of the CR circuit that will constitute by variable resistor 116 and capacitor 114 just and the operational amplifier 112 formed input impedance that is connected in parallel.Therefore, the loop gain loss of the feedback loop that is caused by the input impedance of all pass circuit for compensation must be with the gain setting of all pass circuit itself more than 1.
For example, if ignoring, the bleeder circuit of the resistance 121,123 that phase-shift circuit 110C is comprised (considers that voltage ratio is 1 situation, a in the promptly above-mentioned formula (2) 1=1 situation), then according to formula (2), phase-shift circuit 110C must be according to the frequency of input from being that 1 times follower circuit moves in as the scope of gain for-1 times inverting amplifier as gain, is 1 in addition value so had better not make the resistance ratio of resistance 118 and 120.Its reason is, as each resistance value of supposing resistance 118,120 is R18, R20, gain when then phase-shift circuit 110C moves as inverting amplifier is-R20/R18, but the gain when moving as follower circuit, always equal 1 with resistance 118 with the resistance ratio of resistance 120 is irrelevant, so, when the resistance ratio of resistance 118 and resistance 120 is not 1, on the whole actuating range of phase-shift circuit 110C, can not satisfying just, the phase place between the input and output changes and the constant ideal conditions of output amplitude.
Add the bleeder circuit that constitutes by resistance 121 and resistance 123 by outlet side at phase-shift circuit 110C, and feed back by the reversed input terminal of this bleeder circuit to operational amplifier 112, just can remain under 1 the situation at resistance ratio with resistance 118 and resistance 120, with the gain setting of phase-shift circuit 110C more than 1.Equally, add the bleeder circuit that constitutes by resistance 141 and resistance 143 by outlet side at phase-shift circuit 130C, and feed back by the reversed input terminal of this bleeder circuit to operational amplifier 132, just can remain under 1 the situation at resistance ratio with resistance 138 and resistance 140, with the gain setting of phase-shift circuit 130C more than 1.
In addition, as ask for Fig. 4, 1 shown in Figure 6 (is benchmark with input voltage Ei, along the hour hands rotation direction, 1≤360 ° of 180 °≤), 2 (is benchmark with input voltage Ei, along the hour hands rotation direction, 2≤180 ° of 0 °≤) from formula (2) or formula (3), then
1＝tan{2ωT 1/(1-ω 2T 1 2)} …(6)
2＝tan{2ωT 2/(1-ω 2T 2 2)} …(7)
For example, at T 1=T 2Under the situation of (=T), when ω=1/T, the phase-shift phase of 2 phase- shift circuit 110C, 130C adds up to 360 °, and carries out above-mentioned tuning action, at this moment, and 1=270 °, 2=90 °.
Figure 10 is the figure of phase relation between the input/output signal of expression 2 phase- shift circuit 110C, 130C, expresses when the signal frequency that be input to prime phase-shift circuit 110C to equate with tuned frequency and the time constant T of each phase-shift circuit 1, T 2Example when equating.
Shown in Figure 10 (A), the output signal S2 of prime phase-shift circuit 110C is that benchmark moves 1=270 ° phase place along the hour hands rotation direction with input signal S1.Then the output signal S3 of level phase-shift circuit 130C is that benchmark moves 2=90 ° phase place along the hour hands rotation direction with input signal S2.Therefore, with 2 phase- shift circuit 110C, 130C cascade connection the time, shown in Figure 10 (C), as the phase place of 360 ° of overall movement.
Yet, when the tuned frequency that sets is higher than the signal frequency that is input to prime phase-shift circuit 110C, be not 360 ° with the result after above-mentioned 1, 2 additions.
Figure 11 is the figure of the relation between the input/output signal of expression tuned frequency each phase-shift circuit when being higher than the signal frequency that is input to prime phase-shift circuit 110C.In addition, the same with the situation of above-mentioned Figure 10 in Figure 11 and hereinafter described Figure 12, the time constant T of each phase-shift circuit is shown as an example 1, T 2Situation when equating.
When tuned frequency is higher than the signal frequency that is input to prime phase-shift circuit 110C, promptly work as the signal frequency of being imported when lower than tuned frequency, can clearly be seen that from Fig. 4 and Fig. 6, in this case, the phase-shift phase 1 of prime phase-shift circuit 110C is less than 270 °, and the phase-shift phase 2 of back level phase-shift circuit 130C is less than 90 °.Therefore, as 1 and φ 2 are shown in Figure 11 (A), Figure 11 (B) respectively, during then with 2 phase- shift circuit 110C, 130C cascade connection, shown in Figure 11 (C), total phase-shift phase is less than 360 °.
But, in these cases, approaching the signal frequency of actual input for making tuned frequency, above-mentioned 1 increase need only be got final product, specifically, can strengthen the both end voltage VR1 of variable resistor shown in Figure 2 116.For example, when forming variable resistor 116, then reduce gate voltage and get final product to strengthen channel resistance with n channel-type FET.
In addition, when tuned frequency is lower than the signal frequency that is input to prime phase-shift circuit 110C, neither 360 ° with the result after above-mentioned 1, 2 additions.
Figure 12 is the figure of the phase relation between the input/output signal of expression tuned frequency each phase-shift circuit when being lower than the signal frequency that is input to prime phase-shift circuit 110C.
When tuned frequency is lower than the signal frequency that is input to prime phase-shift circuit 110C, promptly work as the signal frequency of being imported when higher than tuned frequency, can clearly be seen that from Fig. 4 and Fig. 6, in this case, the phase-shift phase 1 of prime phase-shift circuit 110C is greater than 270 °, and the phase-shift phase 2 of back level phase-shift circuit 130C is greater than 90 °.Therefore, as 1 and φ 2 are shown in Figure 12 (A), Figure 12 (B) respectively, during then with 2 phase- shift circuit 110C, 130C cascade connection, shown in Figure 12 (C), total phase-shift phase is greater than 360 °.
But, in these cases, approaching the signal frequency of actual input for making tuned frequency, the absolute value of above-mentioned 1 need only be reduced get final product, specifically, can reduce the both end voltage VR1 of variable resistor shown in Figure 2 116.For example, when forming variable resistor 116, then improve gate voltage and get final product to reduce channel resistance with n channel-type FET.
As mentioned above, in above-mentioned tuning circuit 1, because being set at identical value, the resistance in the phase- shift circuit 110C 118 and the resistance value of resistance 120 also simultaneously the resistance value of resistance in the phase- shift circuit 130C 138 and resistance 140 is set at identical value, so the amplitude variations in the time of can preventing to change tuned frequency, thereby can obtain the substantially invariable tuning output of amplitude.
Particularly, by suppressing the amplitude variations of tuning output, can strengthen above-mentioned resistance ratio n, thereby can increase the Q value of tuning circuit 1.That is, if loop gain and frequency have dependence, then under the low frequency of gain, even strengthen resistance ratio n, the Q value can not increase yet, and under the high frequency of gain, loop gain is vibrated sometimes as surpassing 1.Therefore, under the big situation of amplitude variations,, resistance ratio n can not be set at too big value, thereby the Q value of tuning circuit reduces also for preventing above-mentioned vibration.On the other hand, in tuning circuit shown in Figure 21, owing in phase- shift circuit 110C, 130C, connected bleeder circuit, so even set resistance ratio n bigger, amplitude variations can not take place in the tuning output of tuning circuit 1 yet.Therefore, in tuning circuit shown in Figure 21, can strengthen resistance ratio n, thereby increase the Q value.
In addition, by being used as feedback signal through the signal after bleeder circuit 160 decay, to import bleeder circuit 160 preceding signals simultaneously takes out as the output of tuning circuit 1, can carry out from input signal, only extracting out the tuning action of assigned frequency component, simultaneously the amplification that this signal of extracting out is stipulated.
In above-mentioned tuning circuit shown in Figure 21, can also with each phase-shift circuit that tuning circuit 1 is comprised in operational amplifier 112 or any one bleeder circuit in the bleeder circuit that is connected of 132 output omit, or its voltage ratio is set at 1.For example, the bleeder circuit in the phase-shift circuit 110C can be omitted and the lead-out terminal of operational amplifier 112 directly is connected with an end of resistance 120.
Like this, omitting and be 1 with gain setting as the bleeder circuit in one of 2 phase-shift circuits that cascade is connected, is value greater than 1 by the gain setting with another phase-shift circuit 110C then, can carry out the tuning action same with tuning circuit shown in Figure 21.
In addition, do not needing to amplify under the situation of work, also back grade the bleeder circuit 160 of phase-shift circuit 130C can omitted, and the output of phase-shift circuit 130C is directly fed back to preceding-stage side.Perhaps, making the resistance value of the resistance 162 in the bleeder circuit 160 is minimum value, thereby voltage ratio is set at 1.
[detailed structure of C. frequency control circuit and action]
Below, frequency control circuit shown in Figure 12 is elaborated.Figure 13 is the circuit diagram of the structure of expression frequency control circuit 2, and the detailed structure of circuit of synchronous rectification 3, pulse conversion circuit 5, polarity discriminating circuit 6 and voltage combiner circuit 7 is shown respectively.
Circuit of synchronous rectification 3 shown in Figure 13 structurally comprises analog switch (AS) 30, voltage comparator 32, level moving device (LS) 34.
The output signal of input tuning circuit 1 on an input (for example reversed input terminal) of voltage comparator 32, another input (for example in-phase input terminal) ground connection.The output of voltage comparator 32, when the current potential of the output signal of tuning circuit 1 becomes L level (for example 0V) during greater than 0V, otherwise, when the current potential of the output signal of tuning circuit 1 becomes H level (for example Gui Ding positive voltage) when 0V is following.Except that above-mentioned output, voltage comparator 32 also has the reversed-phase output of a signal after the output logic counter-rotating, and this reversed-phase output is connected in hereinafter described polarity discriminating circuit 6.
Level moving device 34 when the signal from voltage comparator 32 output is carried out polarity inversion, carries out level and moves, and the square wave that will have a voltage level of positive polarity and negative polarity is exported as contrast signal.
Analog switch 30 and contrast signal synchronization action from level moving device 34 outputs, predetermined timing make with the input signal of the tuning circuit 1 of the parallel input of contrast signal by or with its cut-out.For example, analog switch 30 passes through input signal when the square wave of contrast signal is in the voltage level of positive polarity, and input signal is cut off when being in the voltage level of negative polarity.
In addition, circuit of synchronous rectification 3 shown in Figure 13, between voltage comparator 32 and analog switch 30, also inserting a level moving device 34, but also level moving device 34 can omitted and the output of voltage comparator 32 is directly made analog switch 30 actions as contrast signal.
Like this, circuit of synchronous rectification 3 synchronously carries out synchronous rectification to the input signal of tuning circuit 1 with the output signal of tuning circuit 1.For example, when the frequency input signal of tuning circuit 1 is consistent with the tuned frequency of tuning circuit 1, have only the half wave rectification wave signal of the positive polarity side of input signal, export as synchronous rectification from circuit of synchronous rectification 3 output.
Pulse conversion circuit 5 shown in Figure 13 structurally comprises voltage comparator 50, reaches the bleeder circuit that is made of resistance 52,54.
The output signal of the analog switch 30 in an input (for example in-phase input terminal) of voltage comparator 50 is gone up input circuit of synchronous rectification 3, the dividing potential drop output of going up the input bleeder circuit at another input (for example reversed input terminal).Then, voltage comparator 50 compares the voltage on two inputs, and exports its comparative result.Constitute an end ground connection of the resistance 52 of bleeder circuit, an end of resistance 54 is connected with negative supply VSS.In addition, the resistance value of resistance 54 is set at the value bigger than the resistance value of resistance 52 (for example big about 100 times), thereby the voltage of the reversed input terminal of voltage comparator 50 is set at the lower level than 0V.
Above-mentioned circuit of synchronous rectification 3 generates component and the opposite polarity component identical with contrast signal polarity.The phase deviation of this opposite polarity representation in components tuning circuit 1, voltage comparator 50 its pulse duration of output and the proportional pulse trains of this phase deviation of pulse conversion circuit 5 inside.Specifically, two kinds of pulse trains that voltage comparator 50 output polarities differ from one another, a pulse train is input to voltage combiner circuit 7, and another pulse train is input to polarity discriminating circuit 6.
As mentioned above, when the signal frequency that is input to tuning circuit 1 is consistent with tuned frequency, can obtain half wave rectification wave completely as synchronous rectification output, so its voltage level is always positive polarity or 0V.And when frequency input signal and tuned frequency are inconsistent, in synchronous rectification output, generating component of voltage with negative polarity with its phase deviation moment corresponding.Therefore, when there is deviation in the frequency of tuned frequency and input signal thereby produces this negative polarity part, with constantly identical moment of generation of this negative polarity part, the output of the voltage comparator 50 in the pulse conversion circuit 5 becomes the L level.
Polarity discriminating circuit 6 shown in Figure 13 structurally comprises 60,61 and 2 D flip- flops 62,63 of 2 negative circuits.
In this example, constitute delay circuit by 2 negative circuits 60,61, after 2 negative circuits 60,61 of the output of the voltage comparator 50 in making pulse conversion circuit 5 by the cascade connection, be input to each clock terminal of trigger 62,63.
Input is identical with the contrast signal sequential of circuit of synchronous rectification 3 and be the different signal of level on the D input terminal of the D flip-flop 62 in polarity discriminating circuit 6.Be input to the signal of this D input terminal, synchronously be latched, and be input on the D input terminal of D flip-flop 63 of next stage with rising from the pulse train of pulse conversion circuit 5 output.Therefore, the D flip-flop 63 of next stage, according to the pulse train of voltage comparator 50 outputs in pulse conversion circuit 5, the H of output expression phase directional or the voltage of L level.
Voltage combiner circuit 7 shown in Figure 13 structurally comprises 2 tristate buffers 700,702, differential amplifier, reaches variable bias circuit, and differential amplifier comprises operational amplifier 704, and variable inclined to one side value circuit is comprising variable resistor 706.
The reversed-phase output of the voltage comparator 50 in the input of one of them tristate buffer 700 and the pulse conversion circuit 5 is connected, and its output is connected in the reversed input terminal of differential amplifier by resistance 710.This tristate buffer 700 moves according to the logic of the signal of the lead-out terminal Q output of the back level trigger 63 in polarity discriminating circuit 6, for example, when the logic of this signal is H, the signal of being imported is exported by previous status, otherwise, when the logic of this signal is L, make output become high impedance status.
Equally, the reversed-phase output of the voltage comparator 50 in the input of another tristate buffer 702 and the pulse conversion circuit 5 is connected, and its output is connected in the in-phase input terminal of differential amplifier by resistance 708.This tristate buffer 702 moves according to the logic of the signal of the reversed-phase output output of the back level trigger 63 in polarity discriminating circuit 6, for example, when the logic of this signal is H, the signal of being imported is exported by previous status, otherwise, when the logic of this signal is L, make output become high impedance status.
Differential amplifier is imported each output of above-mentioned 2 tristate buffers 700,702 respectively on differential input terminal, with the multiplication factor of regulation its difference is amplified, and the filtering action of stipulating simultaneously to be removing high fdrequency component, and generates control voltage.
This differential amplifier specifically, outside the division operation amplifier 704, structurally also comprises: the capacitor 714 that is plugged on the reversed input terminal of operational amplifier 704 and the feedback resistance between the lead-out terminal 712 and is connected in parallel with this feedback resistance 712; The capacitor 718 that is plugged on the in-phase input terminal of operational amplifier 704 and the resistance between the ground 716 and is connected in parallel with this resistance 716, be used for the signal voltage level from tristate buffer 702 outputs is carried out dividing potential drop, thereby between two inputs of operational amplifier 704, adjust; And be plugged on the reversed input terminal and the capacitor between the ground 720 of operational amplifier 704.
In addition, the movable terminal of the variable resistor 706 that 2 fixed terminals are connected with positive supply Vdd and negative supply Vss is connected by the reversed input terminal of resistance 722 with operational amplifier 704.Therefore, by the biasing circuit that forms by this variable resistor 706, set the bias voltage of regulation at the output of operational amplifier 704.And when reality forms on Semiconductor substrate with this variable resistor 706, can utilize active element formation such as FET.
When the tuned frequency of tuning circuit 1 is consistent with frequency input signal when error free (), this biasing circuit is used to set the voltage that applies on the grid of the variable resistor 116 that should be comprised at a phase-shift circuit 110C of tuning circuit 1.
The frequency control circuit 2 of this example has above-mentioned detailed structure, and below the branch different situations illustrate its detailed action.
[when the C-1. tuned frequency is higher than frequency input signal]
Figure 14 is the time diagram of tuned frequency when being higher than the signal frequency that is input to tuning circuit 1 of expression tuning circuit 1, and the input and output sequential of each component part in the frequency control circuit 2 is shown.This figure (A)～(N) is corresponding with the symbol A～N that provides in Figure 13 circuit diagram.In addition, the hatched example areas that comprises in this figure (I)～(N) is corresponding to uncertain part, and in fact its state determines according to the waveform state of the moment input and output before the input and output waveform of each component part shown in this figure.
When tuned frequency is higher than the frequency input signal of tuning circuit 1, shown in Figure 11 (C), total phase-shift phase of 2 phase- shift circuit 110C, 130C is less than 360 °, so as, then can obtain the phase relation shown in Figure 14 (A), (B) at 2 signals of the input and output of observing tuning circuit 1 sometime.
Voltage comparator 32 in the circuit of synchronous rectification 3, output H level signal when the output signal voltage level of tuning circuit 1 is lower than 0V, output L level signal when being higher than 0V.Therefore, shown in Figure 14 (C) from voltage comparator 32 output have the frequency identical and phase place with tuning output and be the L level when the voltage level of tuning output has positive polarity, be the square wave of H level when the voltage level of tuning output has negative polarity on the contrary.
Voltage comparator 32, except that above-mentioned output, the signal behind its logic inversion of reversed-phase output output also, its waveform is shown in Figure 14 (D).
Logic inversion is carried out in the output of the voltage comparator 32 shown in 34 couples of Figure 14 of level moving device (C), and shown in Figure 14 (E), output has the equal positive polarity of absolute value and the square wave of reverse voltage state.
Analog switch 30 carries out the on-off action of switch according to the voltage level from the square wave of this level moving device 34 outputs.When the tuned frequency of tuning circuit 1 is higher than frequency input signal, shown in Figure 14 (F), the waveform that takes out in front end and half wave rectification wave waveform devious slightly completely, moment of promptly shifting to an earlier date a little from analog switch 30 output in the moment than the first half of taking out tuning output.
Voltage comparator 50, output only are the L level when the output-voltage levels of this analog switch 30 is lower than 0V, in addition are the pulse train of H level.Therefore, when from the synchronous rectification output of analog switch 30 output when front end and half wave rectification wave have deviation slightly, shown in Figure 14 (G), with this front end deviation time corresponding in, the output of voltage comparator 50 becomes the L level.
Voltage comparator 50, except that above-mentioned output, the signal behind its logic inversion of reversed-phase output output also, its waveform is shown in Figure 14 (H).
Prime trigger 62 in the polarity discriminating circuit 6, the output of voltage comparator 50 from the L electrical level rising be the H level the moment (exactly, be the moment that the signal of output after by 2 negative circuits 60,61 that make voltage comparator 50 rises), be taken into and keep the signal logic of the reversed-phase output output of the voltage comparator 32 in the circuit of synchronous rectification 3.As Figure 14 (G) with (D), when the signal from voltage comparator 50 outputs rose, the signal of exporting from reversed-phase output of voltage comparator 32 became the H level, so, shown in Figure 14 (I), by trigger 62 this logic of maintenance H of prime.
In addition, the trigger 63 of back level, exporting from the L electrical level rising at the next one of voltage comparator 50 is the moment of H level, is taken into and keeps the output of prime trigger 62, and shown in Figure 14 (J), from lead-out terminal Q output logic H signal.In addition, shown in Figure 14 (K), the logic L signal of the sub-output of reversed-phase output of going back slave flipflop 63 after with this logic H counter-rotating.
Like this, when tuned frequency is higher than the frequency input signal of tuning circuit 1, from the lead-out terminal Q output logic H signal of back grade trigger 63, and from the sub-output logic L of reversed-phase output signal.Therefore, as be conceived to the action of 2 tristate buffers 700,702 in the voltage combiner circuit 7, then the output of the tristate buffer 702 of input logic L signal becomes high impedance status on control terminal, the tristate buffer 700 of input logic H signal on control terminal only, shown in Figure 14 (L), move as buffer.
In addition, because the output of tristate buffer 702 is by resistance 708 and 716 ground connection, so the current potential of its output becomes 0V shown in Figure 14 (M).
, tristate buffer 700, its input is connected with the reversed-phase output of voltage comparator 50, and its lead-out terminal is being connected by the reversed input terminal of resistance 710 with operational amplifier 704.Therefore, when input logic H signal on control terminal and tristate buffer 700 only have function as buffer, be input to the reversed input terminal of operational amplifier 704 by resistance 710 from the signal of the anti-phase terminal output of voltage comparator 50.
When importing positive pulse in a manner described on the reversed input terminal of operational amplifier 704, corresponding to this pulse input, the voltage of the lead-out terminal of operational amplifier 704 reduces.But because of in fact being connected capacitor 720 between the reversed input terminal of operational amplifier 704 and the ground, being connected capacitor 714 and output voltage is carried out filtering between the lead-out terminal of operational amplifier 704 and the reversed input terminal, so, shown in Figure 14 (N), the differential amplifier that comprises operational amplifier 704, only make with by the corresponding output voltage of the signal pulse width of tristate buffer 700 inputs, promptly control voltage and gently reduce.
In this manner, the control voltage that feeds back to tuning circuit 1 reduces, and the tuned frequency of tuning circuit 1 is changed to the low frequency direction.Carry out this control repeatedly, till frequency input signal and the elimination of the deviation between the tuned frequency with tuning circuit 1, through after the stipulated time, tuned frequency is consistent with the frequency of input signal.
[when the C-2. tuned frequency is lower than frequency input signal]
Figure 15 is the time diagram of tuned frequency when being lower than the signal frequency that is input to tuning circuit 1 of expression tuning circuit 1, and the input and output sequential of each component part in the frequency control circuit 2 is shown.The same with Figure 14, Figure 15 (A)～(N) is corresponding with the symbol A～N that provides in Figure 13 circuit diagram.
When tuned frequency is lower than the frequency input signal of tuning circuit 1, shown in Figure 12 (C), total phase-shift phase of 2 phase- shift circuit 110C, 130C is greater than 360 °, so as, then can obtain the phase relation shown in Figure 15 (A), (B) at 2 signals of the input and output of observing tuning circuit 1 sometime.
Voltage comparators 32 outputs in the circuit of synchronous rectification 3 and the synchronous signal (Figure 15 (C)) of tuning output of tuning circuit 1 in level moving device 34, are carried out anti-phase amplification to this signal, and the level of stipulating simultaneously moves (Figure 15 (E)).Analog switch 30 only passes through the input signal of tuning circuit 1 during for positive polarity when the voltage level of the output signal of level moving device 34, so become the output waveform shown in Fig. 5 (F).
Therefore, 50 outputs of the voltage comparators in pulse conversion circuit 5 voltage levels the output waveform shown in Figure 15 (F) become the pulse train (Figure 15 (G)) that has the regulation positive voltage in time of negative polarity for 0V in the time in addition.
Simultaneously, trigger 62 in the polarity discriminating circuit 6, synchronously be taken into and preserve the signal (Figure 15 (D)) of the reversed-phase output output of the voltage comparator 32 in the circuit of synchronous rectification 3 with the rising of this pulse train, but because of the rising of above-mentioned square wave is risen constantly roughly at synchronization with the output of the voltage comparator 32 shown in Figure 15 (D) constantly, so, under this state, might before determining, the input data of trigger 62 carry out being taken into of data.Negative circuit the 60, the 61st is the delay circuit of avoiding this unsuitable situation to insert, by with data be taken into the time delay official hour, can prevent from before the input data are determined, to be taken into data.
In structure shown in Figure 13, adopt 2 negative circuits 60,61 to constitute delay circuit, but it is also conceivable that the method that adopts the negative circuit more than 4 or do not carry out the various realization delay circuits such as a plurality of buffers of logic inversion.
In the manner described above, 2 triggers 62,63 in the polarity discriminating circuit 6 are taken into the 0V part (being equivalent to logic L) of signal of the reversed-phase output output of the voltage comparator 32 in the circuit of synchronous rectification 3 respectively, so, export logic L and logic H signal shown in Figure 15 (J), (K) respectively from the lead-out terminal Q of the trigger 63 of back level and reversed-phase output thereof.
Each output signal of this trigger 63, as with situation shown in Figure 14, promptly compare with the situation that tuned frequency is higher than the frequency of input signal, then have opposite logic state, and just the tristate buffers 702 in the voltage combiner circuit 7 move (Figure 15 (L), (M)) as buffer.Therefore, structurally comprise the positive pulse that input on the in-phase input terminal of differential amplifier of operational amplifier 704 has the predetermined pulse width, gently rise (Figure 15 (N)) from the control voltage of this differential amplifier, and the tuned frequency of tuning circuit 1 is changed to high frequency direction to tuning circuit 1 output.Carry out this control repeatedly, up to till not having deviation between the frequency input signal of tuning circuit 1 and the tuned frequency, through after the stipulated time, tuned frequency is consistent with the frequency of input signal.
Like this,, then there is not phase difference between the input/output signal that makes tuning circuit 1, can makes tuned frequency follow the tracks of the frequency of input signal and consistent all the time with it by controlling as mechanical tuning device according to this example.Therefore, when for example in the receiver of superhet, using, can make tuned frequency consistent at an easy rate with the carrier frequency of broadcast wave of being imported etc.
In addition, realize the tuning circuit 1 and the frequency control circuit 2 of the mechanical tuning device of this example, constitute by various digital circuits such as trigger and operational amplifier, capacitor, resistance, because every kind of element can form on Semiconductor substrate, thus mechanical tuning device whole or comprise the integral body of mechanical tuning device and peripheral circuit thereof can be integrated on Semiconductor substrate.
Particularly, mechanical tuning device integral body is being carried out when integrated, should be taken into account that the circuit parameter on every chip block of making will produce big discrete discrepancy, thereby frequency characteristic do not fix, even but in this case as adopt the mechanical tuning device of this example, then because of changing the tuned frequency of tuning circuit 1, make its tracking have the input signal of assigned frequency, so the discrete discrepancy of tuning characteristic does not influence actual tuning characteristic, thereby can realize the characteristic of all-the-time stable.
In addition, mechanical tuning device integral body is being carried out when integrated, should be taken into account that also the variations in temperature of various component parameters such as resistance when using changes, but because of in the tuning control manner of this example, carrying out consistent with the frequency of input signal all the time control, so, even under the situation that various component parameters change, also can carry out suitable feedback, suppress the variation of tuned frequency.
The mechanical tuning device of this example, can also be with the output signal (tuning output) of tuning circuit 1 as contrast signal, carry out the synchronous rectification corresponding by circuit of synchronous rectification 3 with input signal, and according to this synchronous rectification signal production burst width and the corresponding signal of phase difference between input/output signal, after in case paired pulses carries out conversion and processing, just can eliminate the influence of the amplitude variations etc. of input signal, thereby can not be subject to the stable tuning control of external factor influence.
In addition, structurally make polarity discriminating circuit 6 comprise 2 triggers 62,63, thereby export about equally and alternately under the situation of the pulse shown in Figure 14 (G) and Figure 15 (G) at for example tuned frequency and frequency input signal, still can correctly carry out the voltage sum operation by voltage combiner circuit 7.Promptly, prime trigger 62, with the rising of the signal shown in Figure 14 (G) or Figure 15 (G) synchronously with the anti-phase output latch of the voltage comparator 32 shown in Figure 14 (D) or Figure 15 (D), and latched data is reflected to control voltage in the moment of pulse shown in output next Figure 14 (G) or Figure 15 (G).Therefore, under the situation of alternately exporting the pulse shown in Figure 14 (G) and Figure 15 (G), when output during a kind of pulse, the voltage of working as with another kind of pulsion phase will be reflected to control voltage, thereby the pulse duration corresponding with phase difference correctly can not be reflected to control voltage., under the situation that 2 (or the even number more than 2) trigger 62,63 cascades are connected, this unsuitable situation that is delayed one-period to the reflection of controlling voltage has not just existed.
[example when D. is applied to the AM receiver]
Below, the situation that the mechanical tuning device of this above-mentioned example is applied to the AM receiver is described.Because in the frequency control circuit 2 of this example, comprising circuit of synchronous rectification 3, so, can be with its synchronous rectification output as using by the AM rectified signal of low pass filter.
Figure 16 is the figure of structure of the mechanical tuning device of expression double as AM detection.Structure shown in this figure tells one the tunnel with the output of the circuit of synchronous rectification 3 in the frequency control circuit shown in Figure 12, and the signal after making along separate routes takes out as the AM rectified signal by low pass filter (LPF) 8.
With such operation that certain contrast signal synchronously switches input signal, generally we can say, be with reference to the operation equivalence of signal and input signal mixing.Here, consider frequency the approximating the 1st and the 2nd signal, and the frequency of supposing the 1st signal is that the frequency of f1, the 2nd signal is f2=(f1+ Δ f) as input signal.In addition, the frequency of supposing contrast signal is fr.
When adopting this contrast signal that input signal is carried out synchronous rectification, be equivalent to can carrying out multiplying with each signal that trigonometric function is represented, so, the component that as a result of generates frequency input signal f1 and f2 and contrast signal frequency f r sum or differ from.Therefore,, can show each frequency component of f1+fr, f1-fr, the 2nd signal and contrast signal in the input signal are multiplied each other, can show each frequency component of f1+ Δ f+fr, f1+ Δ f-fr by the 1st signal and contrast signal in the input signal are multiplied each other.
When the frequency f 1 of the frequency f r of contrast signal and the 1st signal is consistent, by the 1st signal and contrast signal are multiplied each other, can show 2f1,0 frequency component, by the 2nd signal and contrast signal are multiplied each other, can show the frequency component of 2f+ Δ f, Δ f.Therefore, as synchronous rectification output, can show 2f+ Δ f, 2f1, Δ f, each frequency component of 0.Here, frequency is the component of " 0 ", it is exactly DC component, in fact in this DC component, contain modulation signal, so by with this DC component with separate except that the alternating current component it (2f+ Δ f, 2f1, Δ f) and only take out DC component, can utilize the detection and the tuning separation of synchronous rectification simultaneously.
When considering domestic AM broadcasting, because of above-mentioned Δ f is 9kHz, so, by utilizing the low pass filter that this frequency component more than 9kHz can be removed, just can only broadcast wave required and the contrast signal same frequency be taken out.
Figure 17 is the circuit diagram of the detailed structure of expression frequency control circuit 2 shown in Figure 16.Each detailed structure of the circuit of synchronous rectification 3 of formation frequency control circuit 2, pulse conversion circuit 5, polarity discriminating circuit 6, voltage combiner circuit 7, identical with the detailed structure of each circuit shown in Figure 13, the output that it is characterized in that analog switch 30 that circuit of synchronous rectification 3 is comprised is input to the voltage comparator 50 in the pulse conversion circuit 5, takes out to the outside simultaneously.
As mentioned above, signal from low pass filter 8 outputs that are located at the circuit of synchronous rectification 3 back levels in the frequency control circuit 2, it itself is exactly the AM rectified signal, so, when the mechanical tuning device with this example is applied to the AM receiver, only get final product, need the AM detecting circuit be set in addition, thereby can make circuit reduction in the back level of mechanical tuning device with original mechanical tuning device.
In addition, the tuning circuit 1 that in this example, uses, as illustrated with detailed structure shown in Figure 2, signal amplitude is unattenuated in theory, even under the situation that tuned frequency changes, also can access the output signal of amplitude constant all the time.But, in fact, in assembling during tuning circuit 1, or as when carrying out emulation experiment then output amplitude having some variations because of the variation of tuned frequency, in some cases, will in output signal, produce distortion owing to the kind of the FET that constitutes variable resistor 116 or variable amplitude etc., as Figure 16 and shown in Figure 17, because the input signal of tuning circuit 1 is carried out synchronous rectification, thus can amplitude variations or generation distortion etc. be affected because of producing by tuning circuit, thereby can take out SN than good AM rectified signal.
In addition, because synchronous rectification output is used for the AM detection, so, the following insensitive interval of forward voltage of adopting when for example diode carries out the AM detection can be eliminated, thereby linear good AM reception can be carried out.Especially, on Semiconductor substrate, carry out when integrated at the whole mechanical tuning device that will comprise the AM detecting circuit, can only use the high silicon diode of forward voltage owing to can not use the low germanium diode of forward voltage etc., so, the detection mode of must employing not using diode, thereby the method that above-mentioned synchronous rectification output double as AM rectified signal is used has lot of advantages.
In Figure 16 and Figure 17, to in the control of frequency control circuit 2, be used for the AM rectified signal after the necessary synchronous rectification output along separate routes, but can certainly be as in existing receiver, carrying out, connect the AM detecting circuit that adopted synchronous rectification or connect the AM detecting circuit of other detection modes of employing in the back level of tuning circuit 1, to obtain the AM rectified signal in the back level of tuning circuit 1.
Figure 18 is the figure that the AM receiver structure of mechanical tuning device shown in Figure 16 has been adopted in expression.
AM receiver shown in Figure 180 structurally comprises Figure 16 and tuning circuit 1 and frequency control circuit 2 and low pass filter 8, high-frequency amplifier circuit 10, low-frequency amplifier circuit 12, loud speaker 14 and antenna 16 shown in Figure 17.
10 pairs of AM ripples that received by antenna 16 of high-frequency amplifier circuit carry out the high frequency amplification and are input to tuning circuit 1.As mentioned above, tuning circuit 1 makes this tuned frequency consistent with the frequency that the AM ripple of being imported has by frequency control circuit 2 control tuned frequencies.
Frequency control circuit 2 detects the phase difference of the input/output signal of tuning circuit 1, with it as error signal, and control to eliminate this phase difference, so, must adjust in advance the variable resistor 706 of the formation biasing circuit in the voltage combiner circuit 7, so that the tuned frequency of tuning circuit 1 is set near the AM wave frequency of wanting to receive.
12 pairs of signals (AM rectified signal) from low pass filter 8 outputs of low-frequency amplifier circuit carry out low frequency and amplify, and from loud speaker 14 output sounds.Also can not adopt loud speaker 14, and be transformed into sound by earphone etc.
In addition, AM receiver shown in Figure 180, from the importation of antenna 16, do not adopting the lc circuit that constitutes by variable capacitor and magnetic rod antenna, but directly extracting the AM ripple of required frequency out by tuning circuit 1, so that the design of importation becomes carries out easily.Therefore, can constitute antenna 16 with the conductive material of stub shape or flexible cord shape, and can carry out high efficiency reception the AM ripple.Specifically, adopt the telescopic antenna in auto radio, use to form antenna 16, or the conductor part of only using earphone can both receive needed AM ripple with good sensitivity as antenna 16, thereby can not adopt at indispensable stick antenna in the past.
In addition, owing to do not use stick antenna not have problems yet, so that comprise tuning circuit 1, frequency control circuit 2 and high-frequency amplifier circuit 10 etc. the AM receiver almost all forming circuits can on Semiconductor substrate, carry out integratedly, also forming circuit can be formed on a slice chip.
[example when E. is applied to the FM receiver]
Below, the situation that the mechanical tuning device of this above-mentioned example is applied to the FM receiver is described.The frequency control circuit 2 of this example when the frequency input signal of tuning circuit 1 changes, can be followed the tracks of this frequency change and changes the control voltage that feeds back to tuning circuit 1.Therefore, change, be the identical frequency component of modulation signal of FM ripple can in this controls voltage, comprising on the principle with the frequency input signal of tuning circuit 1, and used as the FM rectified signal.
Figure 19 is the figure of structure of the mechanical tuning device of expression double as FM detection.Structure shown in this figure is replaced as voltage combiner circuit 7A with the voltage combiner circuits 7 in the control signal generative circuit shown in Figure 14, and with take out the FM rectified signal from this voltage combiner circuit 7A concurrently to the control voltage of tuning circuit 1 feedback.
Figure 20 is the circuit diagram of the detailed structure of expression frequency control circuit 2 shown in Figure 19.Constitute circuit of synchronous rectification 3, pulse conversion circuit 5, and each detailed structure of polarity discriminating circuit 6 of frequency control circuit 2, identical with the detailed structure of each circuit shown in Figure 13, the structure of voltage combiner circuit 7A has some different with voltage combiner circuit 7 shown in Figure 13.
Voltage combiner circuit 7A, comprising 2 tristate buffers 700,702 and being connected thereafter on the differential amplifier this point that comprises operational amplifier 704 of level and, identical with voltage combiner circuit 7 shown in Figure 13 changing arbitrarily on the bias voltage this point of the control voltage that puts on tuning circuit 1 from voltage combiner circuit 7A by the resistance value of control variable resistor 706.
And except said structure, voltage combiner circuit 7A also has structure and essentially identical the 2nd differential amplifier of above-mentioned the 1st differential amplifier in the back level of 2 tristate buffers 700,702.
Specifically, the 2nd differential amplifier structurally comprises operational amplifier 724, the capacitor 734 that is plugged on the reversed input terminal of operational amplifier 724 and the feedback resistance between the lead-out terminal 732 and is connected in parallel with this feedback resistance 732, be plugged on and be used between the in-phase input terminal of operational amplifier 724 and the ground by to carrying out dividing potential drop and resistance of adjusting between two inputs at operational amplifier 724 736 and the capacitor 738 that is connected in parallel with this resistance 736 through the signal voltage level of resistance 728 inputs from tristate buffer 702, and be connected by the reversed input terminal and the capacitor between the ground 740 of resistance 730 from the operational amplifier 724 of tristate buffer 700 input signals.
Like this, the 2nd differential amplifier has the structure identical with the 1st differential amplifier.But, the 1st differential amplifier is connecting the biasing circuit that is made of variable resistor 706, this biasing circuit is used to be set in the bias voltage that applies on the grid of the variable resistor 116 that the phase-shift circuit 110C of tuning circuit 1 comprised, because of this circuit and FM detection action does not have direct relation, so the 2nd differential amplifier does not connect this circuit.
In addition, in the 1st differential amplifier, voltage by the electrostatic capacitance of adjusting capacitor 714 grades that are connected in parallel with feedback resistance 712 to the output that appears at operational amplifier 704 carries out filtering, so that obtain changing and control voltage stably, but in the 2nd differential amplifier, from the voltage of the output that appears at operational amplifier 724, remove the high fdrequency component more than about 20kHZ by the electrostatic capacitance of adjusting the capacitor 734,738 that is connected in parallel with feedback resistance 732 or 740.Therefore the frequency component that can take out from second differential amplifier below about 20kHz promptly can be taken out FM rectified signals such as FM sound.
As the general structure of the FM receiver that comprises mechanical tuning device shown in Figure 20, can intactly adopt most of structure (removing low pass filter 8) of receiver shown in Figure 180.That is, carry out high frequency by 10 pairs of FM ripples that receive by antenna 16 of high-frequency amplifier circuit and amplify, be input to tuning circuit 1 then.By the control of tuning circuit 1 by frequency control circuit 2, only extract FM ripple (carrier wave) out with required frequency, and the frequency control circuit 2 output FM rectified signals from carrying out this control.After this FM rectified signal is amplified by low-frequency amplifier circuit 12, from loud speaker 14 outputs.When considering various data such as characters, the back level of low-frequency amplifier circuit 12 need only be replaced as data processing circuit and get final product as the FM modulation signal.
In addition, the same during with the AM receiver, frequency control circuit 2 shown in Figure 20 detects the phase difference of the input/output signal of tuning circuit 1, with it as error signal, and control to eliminate this phase difference, so, must adjust in advance the variable resistor 706 of the formation biasing circuit in the voltage combiner circuit 7A, so that the tuned frequency of tuning circuit 1 is set near the FM wave frequency of wanting to receive.
Like this, the time constant of the filter circuit that differential amplifier comprised by the voltage combiner circuit 7 in the control circuit 2 of adjusting frequency, can from the signal that carries out the FM modulation that is input to tuning circuit 1, only take out the FM modulation signal at an easy rate, thereby when mechanical tuning device shown in Figure 20 is applied to the FM receiver, only get final product, need the FM detecting circuit be set in addition in the back level of mechanical tuning device with original mechanical tuning device. thereby can make circuit reduction.
In addition, in existing FM receiver, be used for the amplitude limiter circuit of after the influence of amplitude variations is eliminated, carrying out the FM detection being provided with between mechanical tuning device and the FM detecting circuit, but in mechanical tuning device shown in Figure 20, owing to adopt the pulse conversion circuit 5 in the frequency control circuit 2 to be transformed into the pulse duration corresponding with phase changing capacity, so be not subjected to the influence of amplitude variations, thereby do not need indispensable in the past amplitude limiter circuit yet.
Figure 19 and Figure 20 have illustrated the situation of taking out the FM rectified signal from frequency control circuit 2 interior voltage combiner circuit 7A, but can certainly be as in existing receiver, carrying out, at back grade of FM detecting circuit that connects amplitude limiter circuit and adopted various detection modes of tuning circuit 1, to obtain the FM rectified signal.
[other examples of F. frequency control circuit (its 1)]
Below, other structure example of frequency control circuit 2 shown in Figure 1 are described.Voltage combiner circuit 7 in the frequency control circuit 2 of detailed structure shown in Figure 13 adopts tristate buffer, but also can adopt other element.
Figure 21 is the detailed circuit diagram of another structure example of expression frequency control circuit, has the structure that the voltage combiner circuit 7 shown in Figure 13 is replaced as voltage combiner circuit 7B.Voltage combiner circuit 7B shown in Figure 21, structurally comprise the signal inversion that will on 2 inputs, import and ask the NOR gate 744,746 of two band inverters of its logic product, comprise in inside operational amplifier 704 differential amplifier, and comprise the biasing circuit of variable resistor 706 in inside.
As voltage combiner circuit 7B shown in Figure 21 and voltage combiner circuit 7 shown in Figure 13 are compared, then except that 2 NOR gates 744,746, the differential amplifier that the structure of differential amplifier and biasing circuit and voltage combiner circuit 7 shown in Figure 13 are comprised and the structure of biasing circuit are identical, difference is, tristate buffer shown in Figure 13 700,702 is replaced as NOR gate 744,746, simultaneously change has been done in the wiring of its input and output.
A NOR gate 744, the output of the negative circuit 61 of back level is connected in an one input and the polarity discriminating circuit 6, the sub connection of reversed-phase output of the trigger 63 of back grade in another input and this polarity discriminating circuit 6.Another NOR gate 746, an one input, the same with above-mentioned NOR gate 744, be connected with the output of negative circuit 61, another input is connected with the lead-out terminal Q of above-mentioned trigger 63.
Figure 22 is the time diagram of tuned frequency when being higher than the signal frequency that is input to tuning circuit 1 shown in Figure 21 of expression tuning circuit 1, expresses the input and output sequential of the circuit of synchronous rectification 3 that constitutes frequency control circuit, pulse conversion circuit 5, polarity discriminating circuit 6, voltage combiner circuit 7B respectively.Figure 22 (A)～(M) is corresponding with the symbol A～M that provides in Figure 21 circuit diagram.
In addition, Figure 22 (A)～(J), identical with Figure 14 (A)～(K) except that Figure 14 (H), below, the action that mainly is conceived to 2 NOR gates 744,746 describes.
When the frequency input signal of tuning circuit 1 is higher than tuned frequency, shown in Figure 22 (I), (J), the back level trigger 63 of polarity discriminating circuit 6, respectively from lead-out terminal Q output logic H signal, from the sub-output logic L of reversed-phase output signal.
Therefore, have only the NOR gate 744 of input logic L signal, will have the logic state counter-rotating with the output signal of the negative circuit 61 of the roughly the same waveform of Figure 22 (G), and the signal shown in output Figure 22 (K).And the NOR gate 746 of input logic H signal, shown in Figure 22 (L), no matter which kind of logic state is the output signal of negative circuit 61 be, output all the time has the signal of logic L state.
Like this, only from the pulse of NOR gate 744 output cathodes, and be input to the reversed input terminal of operational amplifier 704 by resistance 710.Therefore, shown in Figure 22 (M), the differential amplifier that comprises operational amplifier 704 only make with from the corresponding voltage of the pulse duration of the signal of NOR gate 744 inputs, promptly control voltage and reduce reposefully.In this manner, the control voltage that feeds back to tuning circuit 1 reduces, and the tuned frequency of tuning circuit 1 is changed to the low frequency direction.
Figure 23 is the time diagram of tuned frequency when being lower than the signal frequency that is input to tuning circuit shown in Figure 21 of expression tuning circuit 1, and Figure 23 (A)～(M) is corresponding with the symbol A～M that provides in Figure 21 circuit diagram.
Shown in Figure 23 (I), (J), opposite when high with tuned frequency, the back level trigger 63 of polarity discriminating circuit 6, respectively from lead-out terminal Q output logic L signal, from the sub-output logic H of reversed-phase output signal.
Therefore, have only the NOR gate 746 of input logic L signal, will have the logic state counter-rotating with the output signal of the negative circuit 61 of the roughly the same waveform of Figure 23 (G), and the signal shown in output Figure 23 (L).And the NOR gate 744 of input logic H signal, shown in Figure 23 (K), no matter which kind of logic state is the output signal of negative circuit 61 be, output all the time has the signal of logic L state.
Like this, only from the pulse of NOR gate 746 output cathodes, and be input to the in-phase input terminal of operational amplifier 704 by resistance 708.Therefore, shown in Figure 23 (M), the differential amplifier that comprises operational amplifier 704 only make with from the corresponding voltage of the pulse duration of the signal of NOR gate 746 inputs, promptly control voltage and rise reposefully.In this manner, the control voltage that feeds back to tuning circuit 1 raises, and the tuned frequency of tuning circuit 1 is changed to high frequency direction.
As mentioned above, as according to mechanical tuning device shown in Figure 21, then when having deviation between the frequency input signal of tuning circuit 1 and the tuned frequency, produce and make the control voltage that this deviation reduces and control, thereby can make tuned frequency follow the tracks of the frequency of input signal and consistent all the time with it.
In addition, mechanical tuning device shown in Figure 21, the same with mechanical tuning device shown in Figure 13 because each composed component can form on Semiconductor substrate, so mechanical tuning device whole or comprise the integral body of mechanical tuning device and peripheral circuit thereof can be integrated on Semiconductor substrate.Particularly, even various component parameters changes, also can carry out suitable feedback, thereby reach stable tuned frequency when integrated in that mechanical tuning device integral body is carried out.In addition, above-mentioned mechanical tuning device can also be eliminated the influence of the amplitude variations etc. of input signal, thereby can not be subject to the stable tuning control of external factor influence.
The elemental motion of mechanical tuning device shown in Figure 21, identical with mechanical tuning device shown in Figure 13, when considering the AM ripple, as shown in figure 16 as the input of tuning circuit 1, can make the output of circuit of synchronous rectification 3 pass through low pass filter 8, thereby take out the AM rectified signal and constitute the AM receiver.
Equally, when considering the FM ripple, as shown in figure 19, can take out the FM rectified signal and constitute the FM receiver from the voltage combiner circuit as the input of tuning circuit 1.In this case, in voltage combiner circuit 7B shown in Figure 21, at the outlet side of 2 NOR gates 744,746 the 2nd differential amplifier (identical) that is connected in parallel, and take out FM rectified signal below about 20kHz from the 2nd differential amplifier with the differential amplifier that structurally comprises operational amplifier 724 in the voltage combiner circuit 7A shown in Figure 20.
[other examples of G. frequency control circuit (its 2)]
Below, other structure example of frequency control circuit 2 shown in Figure 1 are described.The voltage combiner circuit 7 of detailed structure shown in Figure 13 adopts tristate buffer to constitute, or figure 21 illustrates the voltage combiner circuit 7B employing NOR gate formation of detailed structure, but also can adopt analog switch to replace these elements.
Figure 24 is the detailed circuit diagram of another structure example of expression frequency control circuit, and its structure is that circuit of synchronous rectification shown in Figure 13 3, pulse conversion circuit 5, polarity discriminating circuit 6 and voltage combiner circuit 7 are replaced into circuit of synchronous rectification 3A, pulse conversion circuit 5A, polarity discriminating circuit 6A and voltage combiner circuit 7C respectively.
Circuit of synchronous rectification 3A structurally comprises analog switch (AS) 35 and voltage comparator 36.This voltage comparator 36, its reversed input terminal ground connection, when the signal potential of importing on its in-phase input terminal during greater than 0V, output becomes the positive voltage level of regulation, on the contrary during less than 0V, output becomes the negative voltage level of regulation.Because adopt this voltage comparator 36, so, can not use level moving device shown in Figure 13 34, and directly produce the voltage of both positive and negative polarity.
Analog switch 35, carry out the on-off action of switch accordingly with signal voltage from voltage comparator 36 output, when voltage comparator 36 is output as the positive voltage of regulation, the input signal of tuning circuit 1 is passed through, when voltage comparator 36 is output as the negative voltage of regulation, this input signal is cut off.
Pulse conversion circuit 5A has and pulse conversion circuit shown in Figure 13 5 essentially identical structures, and its difference is that voltage comparator shown in Figure 13 50 is replaced into voltage comparator 58.This voltage comparator 58, when the voltage level of the synchronous rectification imported on its in-phase input terminal output was lower than 0V, the output negative pole pulse was when the voltage level of synchronous rectification output is 0V or during for positive polarity, the voltage level of output signal becomes 0V.
Polarity discriminating circuit 6A structurally comprises the voltage comparator 64 of the pulse train of exporting the voltage status with both positive and negative polarity, 2 negative circuits 65,66 of moving as delay circuit, reaches 2 triggers 67,68.
On 2 input terminals of voltage comparator 64, import the signal of on 2 input terminals of above-mentioned voltage comparator 58, importing concurrently, in voltage comparator 64, carry out the action same with voltage comparator 58, its difference is, exports the pulse train of the voltage status with positive polarity or negative polarity according to its comparative result.
In addition, 65,66 and 2 triggers 67,68 of 2 negative circuits, corresponding to 60,61 and 2 triggers 62,63 of 2 negative circuits shown in Figure 13, and carry out essentially identical action, but difference is logic H corresponding to the positive voltage of regulation, the logic L negative voltage corresponding to regulation.
Voltage combiner circuit 7C, the 1st inverting amplifier that structurally comprises 2 analog switches (AS) 750,752, constitutes by operational amplifier 754 and 2 resistance 756,758, the 2nd inverting amplifier that constitutes by operational amplifier 760 and 2 resistance 764,766, and resistance 766 be connected in parallel be used for to the output voltage of the 2nd inverting amplifier carry out the capacitor 768 of filtering, and by being connected the biasing circuit that variable resistor 770 between positive-negative power Vdd, the Vss and resistance 772 constitute.
An analog switch 750 carries out the on-off action of switch according to the signal voltage level of the lead-out terminal Q output of the back level trigger 68 in polarity discriminating circuit 6A.When the signal logic from lead-out terminal Q output be H, when promptly applying positive assigned voltage, analog switch 750 makes the signal of voltage comparator 58 outputs in the pulse conversion circuit 5A be input to the 1st inverting amplifier by resistance 756.
The 1st inverting amplifier makes from the polarity of the signal voltage of this analog switch 750 outputs anti-phase, and the signal after making this anti-phase is input to the 2nd inverting amplifier by resistance 762.
And another analog switch 752 carries out the on-off action of switch according to the signal voltage level of the reversed-phase output output of the back level trigger 68 in polarity discriminating circuit 6A.When the signal logic from reversed-phase output output be H, when promptly applying positive assigned voltage, analog switch 752 makes the signal of voltage comparator 58 outputs in the pulse conversion circuit 5A be input to the 2nd inverting amplifier by resistance 768.
On the reversed input terminal of the 2nd inverting amplifier, connecting resistance 762 that an end is connected with the output of the 1st inverting amplifier, resistance 772 that an end is connected with the biasing circuit that is made of resistance 770, and the resistance 764 that is connected with the output of analog switch 752 of an end.The 2nd inverting amplifier further makes the polarity of the voltage after this addition anti-phase.In addition, also carry out the filtering of voltage concurrently by capacitor 768 and this anti-phase action.
Below, explanation is when the action of tuned frequency mechanical tuning device shown in Figure 24 during above and below the frequency input signal of tuning circuit 1 respectively.
Figure 25 is the time diagram of tuned frequency when being higher than the signal frequency that is input to tuning circuit 1 shown in Figure 24 of expression tuning circuit 1, and the action sequence of the circuit of synchronous rectification 3A, the pulse conversion circuit 5A that constitute frequency control circuit, polarity discriminating circuit 6A, each structure of voltage combiner circuit 7C is shown.Each time waveform of Figure 25 (A)～(M) is corresponding with the symbol A～M that provides in Figure 24 circuit diagram.
When tuned frequency is higher than the frequency input signal of tuning circuit 1, produce the phase difference suitable, so as observing when 2 signal waveforms sometime, its phase relation is shown in Figure 25 (A), (B) with this frequency departure.
Voltage comparator 36 in the circuit of synchronous rectification 3A, when the voltage level of the output signal of tuning circuit 1 was lower than 0V, output had the L level signal of the negative voltage of regulation, and when being higher than 0V, output has the H level signal of the positive voltage of regulation.Therefore, shown in Figure 25 (C), have the frequency identical and the square wave of phase place from voltage comparator 36 output with tuning output.
Analog switch 35 carries out the on-off action of switch according to the voltage level from the square wave of this voltage comparator 36 outputs.When the frequency of the tuning output of tuning circuit 1 is higher than input signal, shown in Figure 25 (D), the waveform that takes out in front end and half wave rectification wave waveform devious slightly completely, moment of promptly shifting to an earlier date a little from analog switch 35 output in the moment than the first half of taking out tuning output.
Voltage comparator 58 in the pulse conversion circuit 5A, output only are L level (negative voltage of regulation) when the output-voltage levels of this analog switch 35 is lower than 0V, in addition are the signal of H level (0V).Therefore, when from the synchronous rectification output of analog switch 35 output when front end and half wave rectification wave have deviation slightly, shown in Figure 25 (E), with this front end deviation time corresponding, export the L level, be the pulse of negative polarity from voltage comparator 58.
In addition, voltage comparator 64 in the polarity discriminating circuit 6A, also carry out same voltage comparison, when from the synchronous rectification output of analog switch 35 output when front end and half wave rectification wave have deviation slightly, shown in Figure 25 (F), with this front end deviation time corresponding, output becomes L level (negative voltage of regulation), is H level (positive voltage of regulation) in the time in addition.Like this, the output of voltage comparator 64, its H level is corresponding to the positive voltage of regulation, and this point is different with above-mentioned voltage comparator 58.
Prime trigger 67 in the polarity discriminating circuit 6A, the output of voltage comparator 64 from the L electrical level rising be the H level the moment (exactly, be the moment that makes behind this moment delay stipulated time), be taken into and keep the logic state signal of voltage comparator 36 outputs in the circuit of synchronous rectification 3A.Shown in Figure 25 (F), (C), when the signal from voltage comparator 64 outputs rose, the signal of exporting from voltage comparator 36 became the H level, so, shown in Figure 25 (G), by trigger 67 this logic of maintenance H of prime.
In addition, the trigger 68 of back level, in the moment that the next one output of voltage comparator 64 is risen, be taken into and keep the output of prime trigger 67, and respectively shown in Figure 25 (H), from the lead-out terminal Q output signal suitable, shown in Figure 25 (I), from the reversed-phase output output signal suitable with logic L with logic H.
Like this, when tuned frequency is higher than the frequency input signal of tuning circuit 1,, have only the change action of an analog switch 750 in the voltage combiner circuit 7C to become on-state from the lead-out terminal Q output logic H signal of back grade trigger 68.Therefore, directly export from the signal (pulse train of negative polarity) (Figure 25 (J)) of voltage comparator 58 outputs from this analog switch 750, and will be from the signal cut (Figure 25 (K)) of voltage comparator 58 outputs by another analog switch 752.
The 1st inverting amplifier that structurally comprises operational amplifier 754 makes from the pulse train of the negative polarity of analog switch 750 output anti-phasely, and is transformed into the pulse train of the positive polarity shown in Figure 25 (L).
The pulse train of this positive polarity is input to the 2nd inverting amplifier that structurally comprises operational amplifier 760, and the 2nd inverting amplifier makes only corresponding with the pulse duration of this positive pulse string output voltage, promptly controls voltage and reduce (Figure 25 (M)) reposefully.
In this manner, the control voltage that feeds back to tuning circuit 1 reduces, and the tuned frequency of tuning circuit 1 is changed to the low frequency direction.Carry out this control repeatedly, till frequency input signal and the elimination of the deviation between the tuned frequency with tuning circuit 1, through after the stipulated time, tuned frequency is consistent with the frequency of input signal.
Figure 26 is the time diagram of tuned frequency when being lower than the signal frequency that is input to tuning circuit 1 shown in Figure 24 of expression tuning circuit 1.Each time waveform of Figure 25 (A)～(M) is corresponding with the symbol A～M that provides in Figure 24 circuit diagram.
When tuned frequency is lower than the frequency input signal of tuning circuit 1, opposite when high with above-mentioned tuned frequency, the reversed-phase output output signal suitable with logic H of the back level trigger 68 in the polarity discriminating circuit 6A has only the change action of another interior analog switch 752 of voltage combiner circuit 7C to become on-state.Therefore, directly export from the signal (pulse train of negative polarity) (Figure 26 (K)) of voltage comparator 58 outputs from this analog switch 752, in contrast, will be by analog switch 750 from the signal cut (Figure 26 (J)) of voltage comparator 58 outputs.
Therefore, shown in Figure 26 (L), the output of the 1st inverting amplifier that is connected with the outlet side of analog switch 750 keeps the voltage status of 0V, only just puts on the 2nd inverting amplifier that structurally comprises operational amplifier 760 as input from the pulse train of the negative polarity of analog switch 752 outputs and the bias voltage of regulation.Therefore, the 2nd inverting amplifier makes only corresponding with the pulse duration of this negative pulse string output voltage, promptly controls voltage rise reposefully (Figure 26 (M)).
In this manner, the control voltage that feeds back to tuning circuit 1 raises, and the tuned frequency of tuning circuit 1 is changed to high frequency direction.Carry out this control repeatedly, till frequency input signal and the elimination of the deviation between the tuned frequency with tuning circuit 1, through after the stipulated time, tuned frequency is consistent with the frequency of input signal.
[other examples of H. frequency control circuit (its 3)]
Below, other structure example of frequency control circuit shown in Figure 1 are described.The voltage combiner circuit 7C of detailed structure shown in Figure 24, has the 1st, the 2nd inverting amplifier, and as required the pulse train of negative polarity is transformed to the pulse train of positive polarity by the 1st inverting amplifier, but owing to what produce from the outset is the positive pulse string, so the 1st inverting amplifier can be omitted.
Figure 27 is the detailed circuit diagram of another structure example of expression frequency control circuit, and its structure is that pulse conversion circuit 5A shown in Figure 24, polarity discriminating circuit 6A and voltage combiner circuit 7C are replaced into pulse conversion circuit 5B, polarity discriminating circuit 6B and voltage combiner circuit 7D respectively.
Pulse conversion circuit 5B have on its in-phase input terminal the synchronous rectification output of analog switch 35 outputs of input in the circuit of synchronous rectification 3A voltage comparator 59, and apply the bleeder circuit that constitutes by resistance 52,54 of the voltage lower slightly at the reversed input terminal of this voltage comparator 59 than 0V.This voltage comparator 59, the result exports the pulse train with positive and negative any voltage level as a comparison.
Polarity discriminating circuit 6B structurally comprises 2 triggers 67,68.These two triggers 67,68 make the positive voltage of logic H and regulation corresponding respectively, logic L is corresponding with the negative voltage of regulation, with in polarity discriminating circuit 6A shown in Figure 24, use the same.
Voltage combiner circuit 7D structurally comprises as delay circuit and 2 negative circuits 780 that are used to take out signal inverting each other simultaneously of moving, 782, take out the diode 784 and the resistance 786 of positive pulse from the output of prime negative circuit 780, take out the diode 788 and the resistance 790 of negative pulse from the output of back level negative circuit 782,2 tristate buffers 700,702, the inverting amplifier that structurally comprises operational amplifier 760 and resistance 766, be connected in parallel with resistance 766 and be used for the output voltage of this inverting amplifier is carried out the capacitor 768 of filtering, and by being connected positive-negative power Vdd, the biasing circuit that variable resistor 770 between the Vss constitutes.Wherein, inverting amplifier and biasing circuit carry out the essentially identical action of circuit that is comprised with voltage combiner circuit 7C shown in Figure 24.
The negative circuit 780 of prime, output will be from the signal behind the logic inversion of the pulse train of the voltage comparator in the pulse conversion circuit 5B 59 output, but when the forward voltage that reaches diode 784 when this voltage of signals level is above, because of flowing through electric current by diode 784 and resistance 786, so only take out the pulse train of positive polarity, and be input to one of them tristate buffer 700.
Equally, the negative circuit 782 of back level, output will be from the signal behind the logic inversion of the pulse train of negative circuit 780 output of prime, but when this voltage of signals level is reduced to the forward voltage of the diode 784 that makes polarity inversion when following, because of flowing through electric current by diode 788 and resistance 790, so only take out the pulse train of negative polarity, and be input to another tristate buffer 702.
The output of the negative circuit 782 of back level also is input to the clock terminal C of the prime trigger 67 in the polarity discriminating circuit 6B.Like this, the signal that voltage comparator 59 in pulse conversion circuit 5B is exported, be input to prime trigger 67 in the polarity discriminating circuit 6B by 2 negative circuits 780,782 that play the delay circuit effect, flowing of this signal and makes in polarity discriminating circuit 6A shown in Figure 24 that to be input to the situation of prime trigger 67 from the signal of voltage comparator 64 outputs 2 negative circuits 65,66 by the delay circuit effect the same.
Like this, in voltage combiner circuit 7D shown in Figure 27, because positive pulse is by diode 784 generations such as grade, so do not need the 1st inverting amplifier that structurally comprises operational amplifier 754 shown in Figure 24.Therefore, after the output of the output that adds a tristate buffer 700 by resistance 762 or 764 simply and another tristate buffer 702, by the inverting amplifier that structurally comprises operational amplifier 760 only with polarity inversion and produce desired control voltage.
Figure 28 is the time diagram of tuned frequency when being higher than the signal frequency that is input to tuning circuit 1 shown in Figure 27 of expression tuning circuit 1, and the action sequence of the input/output signal of each circuit that constitutes frequency control circuit is shown.Figure 28 (A)～(N) is corresponding with the symbol A～N that provides in Figure 27 circuit diagram respectively.
In addition, Figure 28 (A)～(I), identical with Figure 25 (A)～(I) except that Figure 25 (E) except that Figure 28 (F), below, mainly be conceived to difference and describe.
When the frequency input signal of tuning circuit 1 and tuned frequency not simultaneously, the signal (Figure 28 (E)) that voltage comparator 59 outputs in pulse conversion circuit 5A have the pulse duration suitable with this phase difference, the prime negative circuit 780 in voltage combiner circuit 7D is exported the signal (Figure 28 (F)) that makes this signal inversion.
As mentioned above, when the voltage of signals from 780 outputs of prime negative circuit is higher than setting, flow through electric current by diode 784 and resistance 786, so, shown in Figure 28 (J), take out the pulse of positive polarity by this diode 784, and be input to tristate buffer 700.Equally, when the voltage of signals from 782 outputs of prime negative circuit is lower than another setting, flow through electric current by diode 788 and resistance 790, so, shown in Figure 28 (K), take out the pulse of negative polarity by this diode 788, and be input to tristate buffer 702.
During this period, when tuned frequency is higher than the frequency input signal of tuning circuit 1, the lead-out terminal Q output signal (Figure 28 (H)) suitable of the back level trigger 68 in the polarity discriminating circuit 6B respectively with logic H, from the reversed-phase output output signal (Figure 28 (I)) suitable with logic L, therefore, shown in Figure 28 (L), (M), just one of them tristate buffer 700 moves as buffer.
Therefore, cycle in accordance with regulations will be from the positive pulse voltage and the regulation bias voltage addition of being set by the biasing circuit that constitutes with variable resistor 770 of one of them tristate buffer 700 outputs, thereby only suitable with the pulse duration of this positive pulse output voltage of the inverting amplifier that structurally comprises operational amplifier 760 is reduced reposefully.In this manner, shown in Figure 28 (N), the control voltage that puts on tuning circuit 1 from voltage combiner circuit 7D reduces, and tuned frequency is changed to the low frequency direction.
Figure 29 is the time diagram of tuned frequency when being lower than the signal frequency that is input to tuning circuit 1 shown in Figure 27 of expression tuning circuit 1.Figure 29 (A)～(N) is corresponding with the symbol A～N that provides in Figure 27 circuit diagram.
When tuned frequency is lower than frequency input signal, the lead-out terminal Q output signal (Figure 29 (I)) suitable of the back level trigger 68 in the polarity discriminating circuit 6B with logic L, from the reversed-phase output output signal (Figure 28 (H)) suitable with logic H, therefore, shown in Figure 29 (L), (M), just another tristate buffer 702 moves as buffer.
Therefore, cycle in accordance with regulations will be from the negative voltage pulse of another tristate buffer 702 outputs with regulation bias voltage addition of being set by the biasing circuit that constitutes with variable resistor 770, promptly carry out subtracting each other of voltage, thereby only suitable with the pulse duration of this negative pulse output voltage of the inverting amplifier that structurally comprises operational amplifier 760 is risen reposefully.In this manner, shown in Figure 29 (N), the control voltage that puts on tuning circuit 1 from voltage combiner circuit 7D raises, and tuned frequency is changed to high frequency direction.
Like this, as according to Figure 24 or mechanical tuning device shown in Figure 27, then when having deviation between the frequency input signal of tuning circuit 1 and the tuned frequency, change control voltage and also control, thereby can make tuned frequency follow the tracks of the frequency of input signal and consistent all the time with it so that this deviation reduces.
In addition, Figure 24 or mechanical tuning device shown in Figure 27, the same with mechanical tuning device shown in Figure 13 because each composed component can form on Semiconductor substrate, so mechanical tuning device whole or comprise the integral body of mechanical tuning device and peripheral circuit thereof can be integrated on Semiconductor substrate.Particularly, even various component parameters changes, also can carry out suitable feedback, thereby set stable tuned frequency when integrated in that mechanical tuning device integral body is carried out.In addition, above-mentioned mechanical tuning device can also be eliminated the influence of the level variation etc. of input signal, thereby can not be subject to the stable tuning control of external factor influence.
The elemental motion of Figure 24 or mechanical tuning device shown in Figure 27, identical with mechanical tuning device shown in Figure 13, when considering the AM ripple as the input of tuning circuit 1, the output of circuit of synchronous rectification 3A that can make Figure 24 corresponding with circuit of synchronous rectification shown in Figure 16 3 or Figure 27 is by low pass filter 8, thereby takes out the AM rectified signal and constitute the AM receiver.
Equally, when considering the FM ripple, shown in the voltage combiner circuit 7A of Figure 19, take out the FM rectified signal and also constitute the FM receiver as the input of tuning circuit 1.In this case, need only be in voltage combiner circuit 7C shown in Figure 24 one group the 3rd and the 4th inverting amplifier be set in addition again and the FM rectified signal that takes out below about 20kHz from the 4th inverting amplifier gets final product at the outlet side of 2 analog switches 750,752.Perhaps, need only be in voltage combiner circuit 7D shown in Figure 27 be connected in parallel the 2nd inverting amplifier and the FM rectified signal that takes out below about 20kHz from the 2nd inverting amplifier gets final product at the outlet side of 2 tristate buffers 700,702.
[the 1st variation of tuning circuit]
The tuning circuit 1 that mechanical tuning device shown in Figure 2 comprised comprises the CR circuit in each phase- shift circuit 110C, 130C, but also can adopt the phase-shift circuit that the CR circuit is replaced into behind the LR circuit that is made of resistance and inductor to constitute tuning circuit.
Figure 30 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the prime phase-shift circuit 110C of displacement tuning circuit 1 shown in Figure 3 is shown.Phase-shift circuit 110L shown in this figure has the CR circuit that is made of capacitor 114 and variable resistor 116 in the phase-shift circuit 110C shown in Figure 3 is replaced as structure behind the LR circuit that is made of variable resistor 116 and inductor 117.
Therefore, the relations such as input and output voltage of phase-shift circuit 110L shown in Figure 30, shown in the polar plot of Figure 31, can be regarded as the both end voltage VL1 that respectively voltage VC1 shown in Figure 4 is replaced as the both end voltage VR1 of variable resistor 116, voltage VR1 shown in Figure 4 is replaced as inductor 117.
In addition, be T as the time constant of supposing the LR circuit that constitutes by inductor 117 and variable resistor 116 1(as the inductance of establishing inductor 117 is that the resistance value of L, variable resistor 116 is R, then T 1=L/R), then the phase-shift phase 3 of phase-shift circuit 110L is identical with 1 in the above-mentioned formula (6).
Figure 32 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the back level phase-shift circuit 130C of displacement tuning circuit 1 shown in Figure 2 is shown.Phase-shift circuit 130L shown in this figure has the CR circuit that is made of resistance 136 and capacitor 134 in the phase-shift circuit 130C shown in Figure 5 is replaced as structure behind the LR circuit that is made of inductor 137 and resistance 136.
Therefore, the relations such as input and output voltage of phase-shift circuit 110L shown in Figure 32, shown in the polar plot of Figure 33, can be regarded as the both end voltage VL2 that respectively voltage VC2 shown in Figure 6 is replaced as the both end voltage VR2 of resistance 136, voltage VR2 shown in Figure 6 is replaced as inductor 137.
In addition, be T as the time constant of supposing the LR circuit that constitutes by resistance 136 and inductor 137 2(as the resistance value of establishing resistance 136 is R.The inductance of inductor 137 is L, then T 2=L/R), then the phase-shift phase 4 of phase-shift circuit 130L is identical with 2 in the above-mentioned formula (7).
Like this, phase-shift circuit 110L shown in Figure 30 and phase-shift circuit 130L shown in Figure 32, respectively with Fig. 3 or phase- shift circuit 110C, 130C equivalence shown in Figure 5, thereby in tuning circuit shown in Figure 21, can be respectively with the phase-shift circuit 110C of prime be replaced into the phase-shift circuit 110L shown in Figure 30, will the back level phase-shift circuit 130C be replaced into the phase-shift circuit 130L shown in Figure 32.The tuned frequency that structurally comprises the tuning circuit of phase-shift circuit 110L, 130L, for example with each phase-shift circuit 110L, 130L in the R/L reciprocal of time constant of LR circuit proportional, because inductance L wherein is easy to reduce by integrated, so, integrated by the integral body of the tuning circuit that structurally comprises 2 phase-shift circuit 110L, 130L is carried out, be easy to make tuned frequency to reach high frequency.
In addition, in tuning circuit shown in Figure 21, also among phase-shift circuit 110C, the 130C any one can be replaced into phase-shift circuit 110L, the 130L shown in Figure 30 or Figure 32.When the phase-shift circuit that will comprise the CR circuit is connected with the phase-shift circuit cascade that comprises the LR circuit and constitutes tuning circuit, integrated as tuning circuit integral body is carried out, then can prevent the tuned frequency that causes because of variations in temperature variation, promptly can carry out temperature-compensating.
If phase-shift circuit 110C shown in Figure 3 and phase-shift circuit 110L shown in Figure 30 are compared, the changing in the opposite direction of each phase-shift phase when gate voltage of the FET that forms variable resistor 116 is changed.For example, in phase-shift circuit 110C, the gate voltage that makes variable resistor 116 rises and when voltage VR1 was lowered, tuned frequency changed to high frequency side.On the other hand, in phase-shift circuit 110L, the gate voltage that makes variable resistor 116 rises and when voltage VR1 was lowered, tuned frequency changed to lower frequency side.Therefore, when phase-shift circuit 110C is replaced as phase-shift circuit 110L, in Figure 13, must be with the transposing that is connected of 2 lead-out terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit 1 from frequency control circuit 2 and tuning circuit 1 is become oppositely.
In addition, in tuning circuit shown in Figure 21, when phase-shift circuit 110L, the 130L that among phase-shift circuit 110C, the 130C of prime and back level at least one is replaced into shown in Figure 30 and Figure 32, also any one bleeder circuit that is connected in each phase-shift circuit in the bleeder circuit of output of operational amplifier 112 or 132 can be omitted.Perhaps, also two bleeder circuits all can be omitted, and adjust the resistance ratio, resistance 138 of resistance 118 and 120 and 140 resistance ratio, thus the loss that compensation produces in the feedback loop of tuning circuit 1.
In addition, do not needing to amplify under the situation of action, the back level bleeder circuit 160 of back level phase-shift circuit can also omitted, and the output of back level phase-shift circuit is directly fed back to preceding-stage side.Perhaps, making the resistance value of the resistance 162 in the bleeder circuit 160 is minimum value, thereby voltage ratio is set at 1.
[the 2nd variation of tuning circuit]
Figure 34 is the circuit diagram of the 2nd variation of expression tuning circuit.Tuning circuit 1A shown in this figure structurally comprises: 2 phase-shift circuit 210C, 230C add up to 360 ° phase shift by the phase shifts ormal weight of inciting somebody to action input exchange signal separately under assigned frequency; And add circuit, respectively by feedback resistance 170 and input resistance 174 (resistance value of supposition input resistance 174 be feedback resistance 170 resistance value n doubly) the output (feedback signal) that will back level phase-shift circuit 230C and the ratio addition of signal (input signal) to stipulate of input on input terminal 190.
In tuning circuit shown in Figure 21, be set at identical value by each resistance value with resistance 118 in the prime phase-shift circuit 110C and resistance 120, amplitude variations when suppressing to work as the frequency change of the AC signal of being imported, and be connected the outlet side of operational amplifier 112 by the bleeder circuit that constitutes by resistance 121 and 123, be value with the gain setting of phase-shift circuit 110C greater than 1.Different therewith, the prime phase-shift circuit 210C that is comprised among the tuning circuit 1A shown in Figure 34, in phase-shift circuit, do not establish bleeder circuit, but just resistance 120 ' resistance value set greater than resistance 118 ' resistance value, thereby be value with the gain setting of phase-shift circuit 210C greater than 1.
In the phase-shift circuit 230C of back level, too with resistance 140 ' resistance value set greater than resistance 138 ' resistance value, thereby be value with the gain setting of phase-shift circuit 230C greater than 1.In addition, feedback resistance 170, lead-out terminal 192 and resistance 178 are connected with the lead-out terminal of phase-shift circuit 230.
In addition, in tuning circuit 1A shown in Figure 34, the output of back level phase-shift circuit 230C is directly fed back, but also can connect a bleeder circuit, and its dividing potential drop output is fed back by feedback resistance 170 in the one-level side of back again of back level phase-shift circuit 230C.
, as mentioned above, the gain that makes phase-shift circuit when the value of setting each resistance is greater than 1 the time, and gain will change along with the frequency of input signal.For example, as consider the phase-shift circuit 210C of prime, then when the frequency of input signal reduces, gain when phase-shift circuit 210C is used as voltage follower is 1 times, and when frequency is high, the gain of phase-shift circuit 210C when the inverting amplifier for-m doubly (m be resistance 120 ' and resistance 118 ' resistance ratio), so when frequency input signal changes, the gain of phase-shift circuit 210C also changes, thereby makes output signal generation amplitude variations.
By the reversed input terminal with resistance 119 and operational amplifier 112 connect and when making frequency input signal low and the gain of Gao Shi consistent, can suppress above-mentioned amplitude variations.Specifically, as suppose resistance 118 ' resistance value be r, resistance 120 ' resistance matter be mr, then be set at mr/ (m-1) by the resistance value with resistance 119, the frequency that just can make input signal is that 0 each gain of phase-shift circuit 210C when infinitely great is consistent.Equally,, also can be connected with the reversed input terminal of operational amplifier 132, suppress the amplitude variations of output signal by the resistance 139 that will have the regulation resistance value for phase-shift circuit 230C.In addition, also an end of resistance 119 and resistance 139 can be connected with earth level fixed potential in addition.
[the 3rd variation of tuning circuit]
In tuning circuit 1A shown in Figure 34, the example that comprises the CR circuit in phase-shift circuit 210C and the 230C has been described, but when comprising the LR circuit, also can have constituted same phase-shift circuit when replacing the CR circuit.
Figure 35 is the circuit diagram of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the prime phase-shift circuit 210C of displacement tuning circuit 1A shown in Figure 34 is shown.Phase-shift circuit 210L shown in this figure has the CR circuit that is made of capacitor 114 and variable resistor 116 in the prime phase-shift circuit 210C shown in Figure 34 is replaced as structure behind the LR circuit that is made of variable resistor 116 and inductor 117.
If phase-shift circuit 210C shown in Figure 34 and phase-shift circuit 210L shown in Figure 35 are compared, the changing in the opposite direction of each phase-shift phase when gate voltage of the FET that forms variable resistor 116 is changed.For example, in phase-shift circuit 210C, the gate voltage that makes variable resistor 116 rises and when the both end voltage of variable resistor 116 was lowered, tuned frequency changed to high frequency side.On the other hand, in phase-shift circuit 210L, the gate voltage that makes variable resistor 116 rises and when the both end voltage of variable resistor 116 was lowered, tuned frequency changed to lower frequency side.Therefore, when phase-shift circuit 210C is replaced as phase-shift circuit 210L, in Figure 13, must be with the transposing that is connected of 2 lead-out terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit 1 from frequency control circuit 2 and tuning circuit 1 is become oppositely.
Figure 36 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the back level phase-shift circuit 230C of displacement tuning circuit 1A shown in Figure 34 is shown.Phase-shift circuit 230L shown in this figure has the CR circuit that is made of resistance 136 and capacitor 134 in the back level phase-shift circuit 230C shown in Figure 34 is replaced as structure behind the LR circuit that is made of inductor 137 and resistance 136.
Like this, prime phase-shift circuit 210C equivalence shown in phase-shift circuit 210L shown in Figure 35 and Figure 34, thereby in tuning circuit 1A shown in Figure 34, can be respectively with the phase-shift circuit 210C of prime be replaced into the phase-shift circuit 210L shown in Figure 35, will the back level phase-shift circuit 230C be replaced into the phase-shift circuit 230L shown in Figure 36.When 2 phase-shift circuit 210C, 230C are replaced as phase-shift circuit 210L, 230L respectively, integrated by the integral body of tuning circuit is carried out, be easy to make tuned frequency to reach high frequency.Also among two phase-shift circuit 210C, the 230C any one can be replaced into phase-shift circuit 210L or 230L.In this case, the effect that has the variation of the tuned frequency that suppresses corresponding with variations in temperature.
In addition, in tuning circuit 1A shown in Figure 34, by resistance 119 or 139 is connected the amplitude variations when preventing that tuned frequency from changing respectively with two phase-shift circuit 210C, 230C, but because of amplitude variations when the variable range of frequency is narrow also diminishes, so also above-mentioned resistance 119,139 can be removed the formation tuning circuit.Perhaps, also can be only will resistance 119 or 139 on one side remove and constitute tuning circuit.
[the 4th variation of tuning circuit]
In above-mentioned tuning circuit 1,1A, the loop gain loss of the feedback loop that constitutes by all pass circuit that comprises 2 phase-shift circuit 110C etc. and feedback resistance 170, be that input impedance by prime phase-shift circuit 110C etc. causes, think the generation of the loss that inhibition causes because of this input impedance, also can insert the follower circuit that constitutes by transistor, and make the signal that is fed back be input to prime phase-shift circuit (for example 110C or 110L etc.) by this follower circuit in the more previous stage side of prime phase-shift circuit 110C etc.
Figure 37 is illustrated in the circuit diagram that inside has tuning circuit one example of follower circuit.Tuning circuit 1B shown in this figure inserts the follower circuit 50 that is made of transistor in the more previous stage side of prime phase-shift circuit 110C, and is in this, different with tuning circuit 1 shown in Figure 2.And follower circuit 50 shown in Figure 37 is so-called source follower circuits, but also can be made of emitter follower circuit.In addition, in Figure 37, also the voltage ratio of bleeder circuit 160 can be set at 1, maybe this bleeder circuit 160 itself be omitted, thereby just carry out simple tuning action, and not amplify action by tuning circuit integral body.
Like this,, then compare, can strengthen the resistance value of feedback resistance 170 and input resistance 174 with tuning circuit 1 grade of Fig. 2 if connect the follower circuit that constitutes by transistor in the more previous stage side cascade of prime phase-shift circuit 110C etc.Especially, on Semiconductor substrate when integrated, as make the resistance value of feedback resistance 170 grades reduce then must increase the occupied area of element the integral body of tuning circuit, so wish to strengthen to a certain extent resistance value.Therefore carrying out when integrated, the follower circuit 50 that connects as shown in figure 37 is effective.
[the 5th variation of tuning circuit]
In tuning circuit shown in Figure 21, the phase-shift phase that 2 phase- shift circuit 110C and 130C add together is 360 °, constitutes tuning circuit but the phase-shift circuit 110C that also the same circuitry phase that does not make phase shifts can be connected with cascade is connected with 130C.
Figure 38 is that the prime that is illustrated in 2 phase-shift circuits has connected the circuit diagram with the structure of the tuning circuit 1C of circuitry phase 150.As shown in the drawing, tuning circuit 1C, structurally comprise have the phase-shift circuit 310C that from phase-shift circuit 110C shown in Figure 3, saves the structure behind resistance 121 and 123, have the phase-shift circuit 330C that from phase-shift circuit 130C shown in Figure 5, saves the structure behind resistance 141 and 143, the same circuitry phase 150 that is connected the prime of phase-shift circuit 310C, the bleeder circuit 160 that constitutes by resistance 162 and 164, and the add circuit that constitutes by feedback resistance 170 and input resistance 174.
Phase- shift circuit 310C, 330C shown in Figure 38, except the lead-out terminal of operational amplifier 112 or 132 does not connect the bleeder circuit this point, have the structure identical with each phase- shift circuit 110C, 130C shown in Figure 3, transfer function is also identical with phase- shift circuit 110C, 130C with phase-shift phase.But, in formula (2), a 1=1, in formula (3), a 2=1.
With circuitry phase 150 by in input exchange signal on the in-phase input terminal and reversed input terminal by resistance 154 ground connection operational amplifier 152 and reversed input terminal and the resistance between the lead-out terminal 156 that is connected operational amplifier 152 constitute.Operational amplifier 152 has the regulation gain by the resistance ratio decision of 2 resistance 154,156.
Phase-shift circuit 310C is because of each resistance value of resistance 118 and 120 is equal, so gain is 1.Equally, phase-shift circuit 330C is because of each resistance value of resistance 138 and 140 is equal, so gain also is 1.Therefore, in above-mentioned tuning circuit 1C, not to obtain gain, but be value greater than 1 with above-mentioned gain setting with circuitry phase 150 by each phase-shift circuit.
Same circuitry phase 150 with said structure does not change input signal phase place ground and exports, and by adjusting its gain, is easy to compensate the decay of the signal amplitude that is caused by bleeder circuit 160 and the loss that produces in feedback loop.In addition, the same with circuitry phase 150 with the above-mentioned follower circuit that constitutes by transistor, also can play the effect of the buffer that connects in the more previous stage side of prime phase-shift circuit 210C.
In addition, same circuitry phase 150 shown in Figure 38 also can be connected Fig. 2 or tuning circuit 1 shown in Figure 34, the prime of 1A etc.
[the 6th variation of tuning circuit]
Above-mentioned each tuning circuit 1,1A, 1B, 1C, add up to the tuning action of stipulating under 360 ° the frequency at the phase-shift phase of 2 phase-shift circuits, but also can will carry out basic identical action 2 phase-shift circuits combinations and constitute tuning circuit, thereby add up to the tuning action of stipulating under 180 ° the frequency at the phase-shift phase of 2 phase-shift circuits.
Figure 39 is the circuit diagram of the 6th variation of expression tuning circuit, in the figure, connects phase-shift circuit 310C ', replaces the back level phase-shift circuit 330C of Figure 38, and connects negative circuit 180, replaces with circuitry phase 150.Back level phase-shift circuit 310C ' replaces having the identical structure with prime phase-shift circuit 310C the variable resistor 116 except connecting the fixing resistance of resistance value 115.
Negative circuit 180 is by in the AC signal of being imported by resistance 184 input on the reversed input terminal and the operational amplifier 182 of in-phase input terminal ground connection and the reversed input terminal and the resistance between the lead-out terminal 186 that are connected operational amplifier 182 constitute.When AC signal is input to the inverting input period of the day from 11 p.m. to 1 a.m of operational amplifier 182 by resistance 184, the inversion signal after being inverted from the lead-out terminal output phase of operational amplifier 182, this inversion signal is input to prime phase-shift circuit 310C.In addition, this negative circuit 180 has the regulation multiplication factor by the decision of the resistance ratio of 2 resistance 184,186, and the resistance value by making resistance 186 can obtain the gain greater than 1 greater than the resistance value of resistance 184.
Simultaneously, as mentioned above, 2 phase- shift circuit 310C and 310C ', along with the frequencies omega of input signal changes to ∞ from 0, its phase place separately is that benchmark moves to 360 ° along the hour hands rotation direction from 180 ° with input voltage Ei.When the time constant of the interior CR circuit of 2 phase- shift circuit 310C and 310C ' identical (establish it and be T), under the frequency of ω=1/T, the phase-shift phase of 2 phase- shift circuit 310C and 310C ' is respectively 270 °.Therefore, by 2 phase- shift circuit 310C and 310C ' totally with 270 ° of phase shifts * 2=540 ° (=180 °), and, by the negative circuit 180 of the prime that is connected 2 phase- shift circuit 310C and 310C ' with phasing back, so, as a whole, having changeed a week thereby phase-shift phase from back level phase-shift circuit 310C ' output phase is 360 ° signal.
In addition, in tuning circuit 1D shown in Figure 39, be not to obtain gain, but be value, thereby the decay that is easy to compensate the signal amplitude that is caused by bleeder circuit 160 reaches the loss that produces in feedback loop greater than 1 with the gain setting of above-mentioned negative circuit 180 by each phase-shift circuit.
[the 7th variation of tuning circuit]
Tuning circuit 1D shown in Figure 39 has provided the example that phase-shift circuit 310C is connected with 310C ' cascade, but when phase-shift circuit 330C shown in Figure 38 is connected with 330C ' cascade, also can carry out tuning action.
Figure 40 is the circuit diagram of the 7th variation of expression tuning circuit, the tuning circuit 1E shown in this figure, and phase-shift circuit 310C and the 310C ' of replacement Figure 39, and cascade is connected with 330C with phase-shift circuit 330C '.The phase-shift circuit 330C ' of prime replaces the resistance 136 except connecting the variable resistor 135 that is made of FET etc., has and the back grade identical structure of phase-shift circuit 330C.
Phase-shift circuit 330C and the 330C ' of Figure 40, as shown in Figure 6, along with the frequencies omega of input signal changes to ∞ from 0, its phase place is that benchmark moves to 180 ° along the hour hands rotation direction from 0 ° with input voltage Ei.When the time constant of the CR circuit in 2 phase-shift circuit 330C identical (establish it and be T), under the frequency of ω=1/T, the phase-shift phase of 2 phase-shift circuit 330C ' and 330C is respectively 90 °.Therefore, by 2 phase-shift circuit 330C ' and 330C totally with 180 ° of phase shifts, and, by the negative circuit 180 of the prime that is connected 2 phase-shift circuit 330C ' and 330C with phasing back, so, as a whole, having changeed a week thereby phase-shift phase from back level phase-shift circuit 330C output phase is 360 ° signal.
In addition, the same with tuning circuit 1D shown in Figure 39, in above-mentioned tuning circuit 1E, not to obtain gain by each phase-shift circuit, but be value, thereby be easy to compensate the decay of the signal amplitude that causes by bleeder circuit 160 and the loss that in feedback loop, produces greater than 1 with the gain setting of above-mentioned negative circuit 180.
In addition, Figure 38～tuning circuit 1C, 1D, 1E shown in Figure 40 in the structure of 2 phase-shift circuits, comprises the CR circuit, but also can structurally comprise the LR circuit.For example in tuning circuit 1C shown in Figure 38, also prime phase-shift circuit 310C can be replaced into the phase-shift circuit that from phase-shift circuit 110L shown in Figure 30, saves behind the bleeder circuit, simultaneously, back level phase-shift circuit 330C is replaced into the phase-shift circuit that from phase-shift circuit 130L shown in Figure 32, saves behind the bleeder circuit
If phase-shift circuit 310C shown in Figure 38 and phase-shift circuit 110L shown in Figure 30 are compared, the changing in the opposite direction of each phase-shift phase when gate voltage of the FET that forms variable resistor 116 is changed.For example, in phase-shift circuit 310C, the gate voltage that makes variable resistor 116 rises and when the both end voltage of variable resistor 116 was lowered, tuned frequency changed to high frequency side.On the other hand, in phase-shift circuit 110L, the gate voltage that makes variable resistor 116 rises and when the both end voltage of variable resistor 116 was lowered, tuned frequency changed to lower frequency side.Therefore, when the phase-shift circuit that Figure 38 or prime phase-shift circuit shown in Figure 39 is replaced as after from phase-shift circuit 110L shown in Figure 30, saving bleeder circuit, in Figure 13, must be with the transposing that is connected of 2 terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit 1 from frequency control circuit 2 and tuning circuit 1 is become oppositely.
In tuning circuit 1C, the 1D of Figure 38～shown in Figure 40,1E, when only carrying out tuning action, bleeder circuit 160 omitted get final product when not carrying out the amplification of signal amplitude.In addition, also can connect bleeder circuit at least one output of the operational amplifier in 2 phase-shift circuits.For example, in tuning circuit 1D shown in Figure 39, if it is the output of the operational amplifier 132 in the output of the operational amplifier 112 in prime phase-shift circuit 310C and the back level phase-shift circuit 330C connects bleeder circuit respectively, then identical with the structure of circuitry phase 150 with the more previous stage side connection of prime phase-shift circuit 110C tuning circuit shown in Figure 21 in.
In addition, Figure 38～same circuitry phase 150 shown in Figure 40 and the link position of negative circuit 180 are not limited to the more previous stage side of the phase-shift circuit that cascade connects, and also can be connected between each phase-shift circuit or the back one-level side of back level phase-shift circuit.
[the 8th variation of tuning circuit]
The 1st of above-mentioned tuning circuit～the 7th variation is all comprising operational amplifier in the inside of phase-shift circuit, but also can the substitution operation amplifier and adopt transistor to constitute phase-shift circuit.
Tuning circuit 1F shown in Figure 41 structurally comprises: 2 phase- shift circuit 410C, 430C make the phase shifts ormal weight of the AC signal of being imported respectively, thereby add up to 360 ° phase shift under the frequencies of regulation; With circuitry phase 450, do not change the phase of output signal of phase-shift circuit 430, and amplify and output with the multiplication factor of regulation; Bleeder circuit 160 is made of back grade the resistance 162 and 164 that is located at circuitry phase 450; And add circuit, will be respectively by feedback resistance 170 and input resistance 174 (resistance value of supposition input resistance 174 be feedback resistance 170 resistance value n doubly) the dividing potential drop output (feedback signal) of bleeder circuit 160 and signal (input signal) addition of on input terminal 190, importing to scale.
And feedback resistance 170 capacitor connected in series 172 and be plugged on input resistance 174 and input terminal 190 between capacitor 176, all be used to stop direct current, its impedance is minimum under operating frequency, promptly have big electrostatic capacitance.
Figure 42 is the figure that illustrates after the structure of prime phase-shift circuit 410C shown in Figure 41 is extracted out.Prime phase-shift circuit 410C shown in this figure, capacitor 414 and variable resistor 416, the drain electrode that is connected FET412 and the resistance between the positive supply 418 between leak in the source that structurally comprise FET412 that grid is connected in input 122, is connected in series in this FET412 and be connected source electrode and the resistance between the ground 420 of FET412.In addition, at least one that also FET412 can be reached among the hereinafter described FET432 is replaced by bipolar transistor.
Here, resistance value as 2 resistance 418,420 that will be connected with drain electrode with the source electrode of above-mentioned FET412 is set at the basic alternating current component that equates and be conceived to be applied to the input voltage on the input 122, then can be respectively from the signal of the source electrode output phase unanimity of FET412, from the drain electrode output phase of the FET412 signal of (180 ° of phase shifts) on the contrary.
In addition, the resistance 426 in the phase-shift circuit 410 shown in Figure 41 is used for FET412 is applied suitable bias voltage.And variable resistor 416 for example, as shown in figure 42, adopts the raceway groove that forms between leak in the source of junction type FET as resistive element, by changing gate voltage, resistance value is changed within the specific limits arbitrarily.
In having the phase-shift circuit 410C of said structure, when on input terminal 122, importing the AC signal of regulation, promptly when applying the alternating voltage (input voltage) of regulation on the grid at FET412, alternating voltage with this input voltage homophase appears on the source electrode of FET412, on the contrary, the alternating voltage that and its amplitude anti-phase with this input voltage equates with voltage on appearing at source electrode appears in the drain electrode of FET412.The amplitude of the alternating voltage that will occur in this source electrode and drain electrode all is assumed to Ei.
Between leaking, the source of this FET412 connecting the series circuit (CR circuit) that constitutes by variable resistor 416 and capacitor 414.Therefore, will appear at the source electrode of FET412 and the voltage in the drain electrode signal after synthetic by variable resistor 416 or capacitor 414 respectively from output 124 output.
Figure 43 is the input and output voltage of expression prime phase-shift circuit 410C and the polar plot that appears at the relation between the voltage on the capacitor etc.
Owing in the source electrode of FET412 and drain electrode, occur respectively and input voltage homophase and anti-phase and voltage amplitude is the alternating voltage of Ei, so the potential difference (alternating current component) of source between leaking is 2Ei.In addition, the voltage VC1 that appears at capacitor 414 two ends and the voltage VR1 that appears at variable resistor 416 two ends differ 90 ° phase place each other, with the two vector synthetic after, the voltage 2Ei between leak in the source that equals FET412.
Therefore, as shown in figure 43, be hypotenuse with 2 times of voltage Ei, can form the right-angled triangle on 2 limits of the both end voltage VR1 quadrature of the both end voltage VC1 that constitutes capacitor 414 and variable resistor 416.Therefore, in the amplitude constant of input signal and just under the situation of frequency change, the both end voltage VR1 of the both end voltage VC1 of capacitor 414 and variable resistor 416 is along semicircle circumferential variation shown in Figure 43.
; as supposition the tie point of capacitor 414 and variable resistor 416 and the potential difference of earth level are taken out as output voltage Eo; then in semicircle shown in Figure 43; can with this output voltage Eo in order to its central point be starting point, the intersection point on circumference is the vector representation of terminal point with voltage VC1 and voltage VR1, its size equals the radius Ei of semicircle.And, because the terminal point of this vector only moves on circumference, so even incoming frequency changes, output amplitude is also with frequency shift, thereby can obtain stable output.
Can also be clear that from Figure 43, because voltage VR1 and voltage VC1 meet at right angle on circumference, so, be applied to input voltage on the grid of FET412 and the phase difference of voltage VR1, when frequencies omega changes from 0 to ∞, be that benchmark is along the variation from 270 ° to 360 ° of hour hands rotation direction with voltage Ei in theory with the input voltage homophase.So the phase-shift phase 5 of the integral body of phase-shift circuit 410C changes between 180 ° to 360 ° according to frequency.And, by changing the resistance value of variable resistor 416, can change phase-shift phase 5.
In addition, be T as the time constant of supposing the CR circuit that constitutes by capacitor 414 and variable resistor 416 1(as the electrostatic capacitance of establishing capacitor 414 is that the resistance value of C, variable resistor 416 is R, then T 1=CR), the transfer function of phase-shift circuit 410C then shown in Figure 42 can not add revises K2 (but a in the formula shown in the ground employing formula (2) 1＜1), phase-shift phase 5 shown in Figure 43 is also identical with the 1 that above-mentioned formula (6) provides.
Equally, Figure 44 is the figure that illustrates after the structure of back level phase-shift circuit 430C shown in Figure 41 is extracted out.Back level phase-shift circuit 430C shown in this figure, capacitor 434 and resistance 436, the drain electrode that is connected FET432 and the resistance between the positive supply 438 between leak in the source that structurally comprise FET432 that grid is connected in input 142, is connected in series in this FET432 and be connected source electrode and the resistance between the ground 440 of FET432.
The same with phase-shift circuit 410C shown in Figure 42, be set at as the resistance value of 2 resistance 438,440 that will be connected with drain electrode with the source electrode of FET432 shown in Figure 44 basic equal and be conceived to be applied to the alternating current component of the input voltage on the input 142, then can be respectively from the signal of the source electrode output phase unanimity of FET432, from the opposite signal of the drain electrode output phase of FET432.
In addition, the resistance 446 in the phase-shift circuit 430 shown in Figure 41 is used for FET432 is applied suitable bias voltage.And be located at the capacitor 148 of the input side of phase-shift circuit 430C, and be used to stop direct current, so that DC component is removed from the output of phase-shift circuit 410C, thereby only to phase-shift circuit 430C input AC component.
In having the phase-shift circuit 430C of said structure, when on input terminal 142, importing the AC signal of regulation, promptly when applying the alternating voltage (input voltage) of regulation on the grid at FET432, alternating voltage with this input voltage homophase appears on the source electrode of FET432, on the contrary, the alternating voltage that and its amplitude anti-phase with this input voltage equates with voltage on appearing at source electrode appears in the drain electrode of FET432.The amplitude of the alternating voltage that will occur in this source electrode and drain electrode all is assumed to Ei.
Between leaking, the source of this FET432 connecting the series circuit (CR circuit) that constitutes by capacitor 414 and resistance 436.Therefore, will appear at the source electrode of FET432 and the voltage in the drain electrode signal after synthetic by capacitor 414 or resistance 416 respectively from output 144 output.
Figure 45 is the input and output voltage of expression back level phase-shift circuit 430C and the polar plot that appears at the relation between the voltage on the capacitor etc.
Owing in the source electrode of FET432 and drain electrode, occur respectively and input voltage homophase and anti-phase and voltage amplitude is the alternating voltage of Ei, so the potential difference of source between leaking is 2Ei.In addition, the voltage VR2 that appears at resistance 436 two ends and the voltage VC2 that appears at capacitor 434 two ends differ 90 ° phase place each other, after the two vector addition, and the potential difference 2Ei between leak in the source that equals FET432.
Therefore, as shown in figure 45, be hypotenuse with 2 times of voltage Ei, can form the right-angled triangle on 2 limits of the both end voltage VC2 quadrature of the both end voltage VR2 that constitutes resistance 436 and capacitor 434.Therefore, in the amplitude constant of input signal and just under the situation of frequency change, the both end voltage VC2 of the both end voltage VR2 of resistance 436 and capacitor 434 is along semicircle circumferential variation shown in Figure 45.
As supposition the tie point of resistance 436 and capacitor 434 and the potential difference of earth level are taken out as output voltage Eo, then in semicircle shown in Figure 45, can with this output voltage Fo in order to its central point be starting point, the intersection point on circumference is the vector representation of terminal point with voltage VR2 and voltage VC2, its size equals the radius Ei of semicircle.And, because the terminal point of this vector only moves on circumference, so even the frequency change of input signal, output amplitude is also with frequency shift, thereby can obtain stable output.
Can also be clear that from Figure 45, because voltage VR2 and voltage VC2 meet at right angle on circumference, so, be applied to input voltage on the grid of FET432 and the phase difference of voltage VC2, when frequencies omega changes from 0 to ∞, the variation from 0 ° to 90 ° in theory.So the overall phase-shift phase 6 of phase-shift circuit 430C changes between 0 ° to 180 ° according to frequency.
In addition, be T as the time constant of supposing the CR circuit that constitutes by capacitor 434 and variable resistor 436 2(as the electrostatic capacitance of establishing capacitor 434 is that C, variable-resistance resistance value are R, then T 2=CR), the transfer function of phase-shift circuit 430C then shown in Figure 44 can not add revises K3 (but a in the formula shown in the ground employing formula (3) 2＜1), phase-shift phase 6 shown in Figure 45 is also identical with the 2 that above-mentioned formula (7) provides.
In a manner described,, in 2 phase- shift circuit 410C, 430C, make the phase shifts ormal weight respectively, thereby output adds up to 360 ° signal by the phase-shift phase of the overall generation of 2 phase- shift circuit 410C, 430C under assigned frequency as Figure 43 and shown in Figure 45.
In addition, same circuitry phase 450 shown in Figure 41 structurally comprises: FET452 is connected resistance 454 respectively, is connected resistance 456 between source electrode and the ground between drain electrode and positive supply; Transistor 458, base stage is connected with the drain electrode of FET452, and collector electrode is connected with the source electrode of FET452 by resistance 460; And resistance 462, be used for FET452 is applied suitable bias voltage.And be located at the capacitor 164 of the prime of same circuitry phase 450 shown in Figure 41, and be used to stop direct current, so that DC component is removed from the output of the phase-shift circuit 430C of back level, thereby only to circuitry phase 450 input AC components.
FET452 is when input exchange signal on its grid, from drain electrode output inversion signal.And transistor 458, when this inversion signal is input to its base stage, from collector electrode output make phase place further counter-rotating signal, promptly as with the phase place of the signal imported at the grid of FET452 be benchmark then for the signal of its homophase, and export these in-phase signals with circuitry phase 450 from this.
Should take out from lead-out terminal 192 as the output of tuning circuit 1 with the output of circuitry phase 450, will be somebody's turn to do output with circuitry phase 450 signal after by bleeder circuit 160 feeds back to prime phase-shift circuit 410C via feedback resistance 170 input side simultaneously.Then, with this feedback signal and signal plus, and the voltage of signals after this addition is put on the input (input 122 shown in Figure 42) of prime phase-shift circuit 410C by resistance 174 input.
In addition, above-mentioned gain with circuitry phase 450, each resistance value decision by above-mentioned resistance 454,456,460, by adjusting the resistance value of each resistance, can compensate by 2 phase- shift circuit 410C, 430C shown in Figure 41, and the decay that causes of bleeder circuit 160 and the loss that in feedback loop, produces, and the loop gain of tuning circuit integral body can be set in below 1.
In addition, owing to take out the output signal of the same circuitry phase 450 before the input bleeder circuits 160 from the lead-out terminal 192 of tuning circuit 1, thus can make tuning circuit 1F itself have gain, thereby can be when carrying out tuning action the amplitude of signal be amplified.
[the 9th variation of tuning circuit]
Tuning circuit shown in Figure 41 comprises the CR circuit in the inside of each phase- shift circuit 410C, 430C, but also can adopt the phase-shift circuit that the CR circuit is replaced into behind the LR circuit that is made of resistance and inductor to constitute tuning circuit.
Figure 46 is the circuit diagram of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the prime phase-shift circuit 410C of displacement tuning circuit 1F shown in Figure 41 is shown.Phase-shift circuit 410L shown in this figure, have the CR circuit that is made of capacitor 414 and variable resistor 416 in the phase-shift circuit 410C shown in Figure 41 is replaced as structure behind the LR circuit that is made of variable resistor 416 and inductor 417, and each resistance value of resistance 418 and resistance 420 is set at identical value.And be plugged on capacitor 419 between the drain electrode of inductor and FET412, be used to stop direct current.
The relations such as input and output voltage of above-mentioned phase-shift circuit 410L, shown in the polar plot of Figure 47, can be regarded as the voltage VL1 that respectively voltage VC1 shown in Figure 43 is replaced as the voltage VR1 at variable resistor 116 two ends, voltage VR1 shown in Figure 43 is replaced as inductor 417 two ends.
In addition, be T as the time constant of supposing the LR circuit that constitutes by inductor 417 and variable resistor 416 1(as the inductance of establishing inductor 417 is that the resistance value of L, variable resistor 416 is R, then T 1=L/R), the transfer function of phase-shift circuit 410L then shown in Figure 46 can not add revises K2 (but a in the formula shown in the ground employing formula (2) 1＜1), phase-shift phase 7 shown in Figure 47 is also identical with the 1 that above-mentioned formula (6) provides.
Therefore, the phase-shift circuit 410C shown in the phase-shift circuit 410L shown in Figure 46 and Figure 42 is equivalence substantially, thereby phase-shift circuit 410C shown in Figure 42 can be replaced into phase-shift circuit 410L shown in Figure 46.
And if phase-shift circuit 410C shown in Figure 42 and phase-shift circuit 410L shown in Figure 46 are compared the changing in the opposite direction of each phase-shift phase when gate voltage of the FET that forms variable resistor 416 is changed.For example, in phase-shift circuit 410C, the gate voltage that makes variable resistor 416 rises and when voltage VR1 was lowered, tuned frequency changed to high frequency side.On the other hand, in phase-shift circuit 410L, the gate voltage that makes variable resistor 416 rises and when voltage VR1 was lowered, tuned frequency changed to lower frequency side.Therefore, when phase-shift circuit 410C is replaced as phase-shift circuit 410L, in Figure 13, must be with the transposing that is connected of 2 terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit from frequency control circuit 2 and tuning circuit is become oppositely.
Figure 48 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the back level phase-shift circuit 430C of displacement tuning circuit 1F shown in Figure 41 is shown.Phase-shift circuit 430L shown in this figure, have the CR circuit that is made of resistance 436 and capacitor 434 in the phase-shift circuit 430C shown in Figure 44 is replaced as structure behind the LR circuit that is made of resistance 436 and inductor 437, and each resistance value of resistance 438 and resistance 440 is set at identical value.And be plugged on capacitor 439 between the drain electrode of resistance 436 and FET432, be used to stop direct current.
The relations such as input and output voltage of above-mentioned phase-shift circuit 430L, shown in the polar plot of Figure 49, can be regarded as the both end voltage VR2 that respectively voltage VR2 shown in Figure 45 is replaced as the both end voltage VL2 of inductor 437, voltage VC2 shown in Figure 45 is replaced as variable resistor 436.
In addition, be T as the time constant of supposing the LR circuit that constitutes by resistance 436 and inductor 417 2(as the resistance value of establishing resistance 436 is that the inductance of R, inductor 417 is L, then T 2=L/R), the transfer function of phase-shift circuit 430L then shown in Figure 48 can not add revises K3 (but a in the formula shown in the ground employing formula (3) 2＜1), phase-shift phase 8 shown in Figure 49 is also identical with the 2 that above-mentioned formula (7) provides.
Therefore, the phase-shift circuit 430C shown in the phase-shift circuit 430L shown in Figure 48 and Figure 44 is equivalence substantially, thereby phase-shift circuit 430C shown in Figure 44 can be replaced into phase-shift circuit 430L shown in Figure 48.
Like this, any one or the both sides among 2 phase-shift circuit 410C shown in Figure 41 and the 430C can be replaced into Figure 46, phase-shift circuit 410L, the 430L that goes out shown in Figure 48.Be replaced under the situation of phase-shift circuit 410L, 430L both sides 2 phase- shift circuit 410C and 430C, integrated by the integral body of tuning circuit is carried out, be easy to make tuned frequency to reach high frequency.
In addition, only among 2 phase-shift circuit 410C, the 430C any one is being replaced under the situation of phase-shift circuit 410L or 430L, the integral body that contains the tuning circuit that constitutes LR circuit inductance device, maybe this inductor is removed is being carried out when integrated, can prevent the tuned frequency that causes because of variations in temperature variation, promptly can carry out so-called temperature-compensating.
And among 2 phase-shift circuit 410C, the 430C at least one is being replaced under the situation of phase-shift circuit 410L or 430L, also bleeder circuit 160 can be omitted and output that will back level phase-shift circuit directly feeds back to preceding-stage side.Perhaps, also the resistance 162 in the bleeder circuit 160 can be removed and only adopt resistance 164.When saving bleeder circuit 160, or when resistance 162 removed, can only carry out tuning action.
[the 10th variation of tuning circuit]
Figure 50 is the circuit diagram of another variation of expression tuning circuit.Tuning circuit 1G shown in this figure structurally comprises: 2 phase- shift circuit 410C, 410C ' add up to 180 ° phase shift by the phase shifts ormal weight of inciting somebody to action input exchange signal separately under assigned frequency; Negative circuit 480 is reversed the output signal of back level phase-shift circuit 410C ' once more; And add circuit, respectively will be from the signal (feedback signal) and the ratio addition of the signal of importing at input terminal 190 (input signal) of negative circuit 480 outputs with regulation by feedback resistance 170 and input resistance 174.
Prime phase-shift circuit 410C, the phase relation of its detailed structure and input and output, with adopt Figure 42 and Figure 43 to illustrate the same, for example, the time constant of supposing the CR circuit that is made of capacitor 414 and variable resistor 416 is T 1, then frequency is ω=1/T 1The time phase-shift phase 5, be 270 ° along hour hands rotation direction (phase lag direction).
Level phase-shift circuit 410C ' then, its basic structure is identical with above-mentioned prime phase-shift circuit 410C, has the structure that the variable resistor in the phase- shift circuit 410C 416 is replaced into the resistance 415 that resistance value fixes.Therefore, for example, the time constant of supposing the CR circuit that is made of resistance 415 and capacitor 414 is T 3, then frequency is ω=1/T 3The time phase-shift phase 5 ', be 270 ° along hour hands rotation direction (phase lag direction).
Like this, the total phase-shift phase by the phase lag direction of the overall generation of 2 phase- shift circuit 410C, 410C ' under the frequency of regulation, equals 5 '=270 °+270 °=540 ° of 5+ (=180 °).
In addition, negative circuit 480 structurally comprises: FET482 is connected with resistance 484 between drain electrode and positive supply and the resistance 486 between source electrode and ground respectively; Reach resistance 488, be used on the grid of FET482, applying the bias voltage of regulation.When on the grid at FET482 during input exchange signal, make inversion signal after the phasing back from the drain electrode output of FET482.In addition, this negative circuit 480 has the regulation gain by the resistance ratio decision of 2 resistance 484,486.
Like this, under assigned frequency, make 180 ° of phase shifts, and phase place is further reversed, thereby be 360 ° by the total phase-shift phase of the overall generation of these 3 circuit by the negative circuit 480 that is connected in back level by 2 phase- shift circuit 410C, 410C '.Therefore, the output of negative circuit 480 is fed back to the input side of prime phase-shift circuit 410C by feedback resistance 170, and with this feedback signal and the signal plus of importing by input resistance 174, simultaneously, by adjusting the gain of negative circuit 480, carry out the tuning action same with tuning circuit shown in Figure 21.
In addition, in tuning circuit 1G shown in Figure 50, the output of negative circuit 480 is fed back by feedback resistance 170, but also can be the same with tuning circuit 1F shown in Figure 41, at the back level connection bleeder circuit 160 of this negative circuit 480.
[the 11st variation of tuning circuit]
Figure 51 is the circuit diagram of another variation of expression tuning circuit.Different with Figure 50, structurally comprise back level phase-shift circuit 430C shown in Figure 41.
Tuning circuit 1H shown in Figure 51 structurally comprises: 2 phase-shift circuit 430C ', 430C add up to 180 ° phase shift by the phase shifts ormal weight of inciting somebody to action input exchange signal separately under assigned frequency; Negative circuit 480 is further reversed the phase place of the output signal of back level phase-shift circuit 430C; And add circuit, respectively will be from the signal (feedback signal) and the ratio addition of the signal of importing at input terminal 190 (input signal) of negative circuit 480 outputs with regulation by feedback resistance 170 and input resistance 174.
Back level phase-shift circuit 430C, the phase relation of its detailed structure and input and output, with adopt Figure 44 and Figure 45 to illustrate the same, for example, the time constant of supposing the CR circuit that is made of capacitor 434 and resistance 436 is T 2, then frequency is ω=1/T 2The time phase-shift phase 6, be 90 ° along hour hands rotation direction (phase lag direction).
And prime phase-shift circuit 410C ', its basic structure is identical with above-mentioned back level phase-shift circuit 430C, has the resistance in the phase- shift circuit 430C 435 is replaced into the structure that can be changed the variable resistor 436 of resistance value by the control voltage that applies from the outside.Therefore, for example, be T as the time constant of supposing the CR circuit that constitutes by variable resistor 436 and capacitor 434 4, then frequency is ω=1/T 4The time phase-shift phase 6 ', be 90 ° along the hour hands rotation direction.
Like this, under assigned frequency, make 180 ° of phase shifts, and phase place is further reversed, thereby be 360 ° by the total phase-shift phase of the overall generation of these 3 circuit by the negative circuit 480 that is connected in back level by 2 phase-shift circuit 430C ', 430C.Therefore, the output of negative circuit 480 is fed back to the input side of prime phase-shift circuit 430C ' by feedback resistance 170, and with this feedback signal and the signal plus of importing by resistance 174, simultaneously, by adjusting the gain of negative circuit 480, carry out the tuning action same with tuning circuit shown in Figure 21.
In addition, the same with tuning circuit shown in Figure 41, in the tuning circuit shown in Figure 51, also can be at the back level connection bleeder circuit 160 of negative circuit 480, thus in tuning, amplify.
Simultaneously, above-mentioned various tuning circuit 1F, 1G, 1H etc., constitute by 2 phase-shift circuits with circuitry phase or 2 phase-shift circuits and negative circuit, and totally to make the phase-shift phase of total by 3 circuit after connecting under assigned frequency be 360 °, thus the tuning action that can stipulate.Therefore, when only being conceived to phase-shift phase, what kind of 3 circuit be linked in sequence by, has the degree of freedom to a certain degree, can determine the order of connection as required.
In addition, in tuning circuit 1G, the 1H shown in above-mentioned Figure 50 and Figure 51, provided the example that comprises the CR circuit in phase-shift circuit inside, but also the phase-shift circuit cascade that comprises the LR circuit in inside can have been connected and the formation tuning circuit.For example, can connect phase-shift circuit 410L shown in Figure 46 to replace the prime phase-shift circuit 410C of tuning circuit shown in Figure 50, also can connect the phase-shift circuit after variable resistor 116 with phase-shift circuit 410L is replaced into the fixing resistance of resistance value, to replace back level phase-shift circuit 410C '.Perhaps, can connect the phase-shift circuit after resistance 436 with phase-shift circuit 430L shown in Figure 48 is replaced into variable resistor, to replace the prime phase-shift circuit 430C ' of tuning circuit shown in Figure 51, also can connect phase-shift circuit 430L to replace back level phase-shift circuit 430C.
[the 12nd variation of tuning circuit]
Figure 52 is the circuit diagram of the 12nd variation of expression tuning circuit.Tuning circuit 1J shown in this figure structurally comprises: with circuitry phase 550, the phase place ground that does not change the AC signal of being imported is exported; 2 phase-shift circuit 510C, 530C make phase of input signals move ormal weight respectively, thereby add up to 360 ° phase shift under the frequency of regulation; Bleeder circuit 160, the resistance 162 and 164 of the back one-level of level phase-shift circuit 530C constitutes by being located at afterwards; And add circuit since respectively by feedback resistance 170 and input resistance 174 (resistance value of supposition input resistance 174 be feedback resistance 170 resistance value n doubly) make the dividing potential drop output (feedback signal) of bleeder circuit 160 and signal (input signal) addition of importing at input terminal 190 to scale.
Play buffer with circuitry phase 550, the purpose that this circuit is set is to produce the loss of signal etc. in order to prevent when prime phase-shift circuit 510C directly is connected with above-mentioned add circuit.With circuitry phase 550, for example constitute by emitter follower circuit or source follower circuit.Be suppressed under the MIN situation in the loss of the component parameters of selecting feedback resistance 170 to wait each element when will directly connect etc., when constituting tuning circuit, also can should save with circuitry phase 550.
Figure 53 is the circuit diagram that illustrates after the structure of the prime phase-shift circuit 510C shown in Figure 52 is extracted out.Prime phase-shift circuit 510C shown in this figure structurally comprises: differential amplifier 512 is used for the multiplication factor of regulation the differential voltage of 2 inputs being amplified back output; Capacitor 514 and variable resistor 516 will be input to the in-phase input terminal of differential amplifier 512 behind the phase shifts ormal weight of the signal of input on the input 122; Resistance 518 and 520 does not change the reversed input terminal that is input to differential amplifier 512 in the phase place of the signal of input on the input 122 after its voltage level dividing potential drop is about 1/2.
Above-mentioned variable resistor 516 for example, shown in Figure 53, adopts the raceway groove that forms between leak in the source of junction type FET as resistive element, by changing gate voltage, resistance value is changed within the specific limits arbitrarily.
When the AC signal of input regulation on the input shown in Figure 53 122, will be applied to voltage Ei dividing potential drop on the input 122 by resistance 518 and resistance 520 is the reversed input terminal that voltage after about 1/2 puts on differential amplifier 512.
On the other hand, when input signal was input to input 122, the signal that occurs on the tie point of capacitor 514 and variable resistor 516 was input to the in-phase input terminal of differential amplifier 512.Because input signal is input to an end of the CR circuit that is made of capacitor 514 and variable resistor 516, so, by this CR circuit phase of input signals is moved the in-phase input terminal that signal voltage behind the ormal weight puts on differential amplifier 512.Signal after the difference that differential amplifier 512 output will put on the voltage of 2 input terminals in a manner described with the multiplication factor of regulation is amplified.
Figure 54 is the input and output voltage of prime phase-shift circuit 510C shown in expression Figure 53 and the polar plot that appears at the relation between the voltage on the capacitor etc.
As shown in the drawing, the voltage VR1 that appears at variable resistor 516 two ends and the voltage VC1 that appears at capacitor 114 two ends differ 90 ° phase place each other, after the two vector addition, equal input voltage Ei.Therefore, in the amplitude constant of input signal and just under the situation of frequency change, the both end voltage VC1 of the both end voltage VR1 of variable resistor 416 and capacitor 514 is along the semicircle circumferential variation shown in Figure 54.
In addition, voltage (the both end voltage Ei/2 of the resistance 520) vector of voltage (the both end voltage VR1 of variable resistor 516) that puts on the in-phase input terminal of differential amplifier 512 and the reversed input terminal that puts on is subtracted each other, can get differential voltage Eo '.This differential voltage Eo ' in the semicircle shown in Figure 54, can be a starting point in order to its central point, the intersection point on circumference is the vector representation of terminal point with voltage VR1 and voltage VC1, and its size equals the radius Ei/2 of semicircle.
With the multiplication factor of regulation with this differential voltage Eo ' amplification after, can get the output voltage Eo of differential amplifier 512.Therefore, in above-mentioned phase-shift circuit 510C, no matter why the frequency of input signal is worth, output voltage Eo is constant, thereby can be used as all pass circuit operation.
In addition, can know from Figure 54 and to find out, because voltage VR1 and voltage VC1 meet at right angle on circumference, so, the phase difference of input voltage Ei and voltage VR1, when frequencies omega changes from 0 to ∞, be that benchmark is along hour hands rotation direction (phase lag direction) variation from 270 ° to 360 ° with input voltage Ei.So the phase-shift phase 9 of the integral body of phase-shift circuit 510C changes between 180 ° to 360 ° according to frequency.
Equally, Figure 55 is the circuit diagram that illustrates after the structure of the back level phase-shift circuit 530C shown in Figure 52 is extracted out.Back level phase-shift circuit 530C shown in this figure structurally comprises: differential amplifier 532 is used for the multiplication factor of regulation the differential voltage of 2 inputs being amplified back output; Resistance 526 and capacitor 534 will be input to the in-phase input terminal of differential amplifier 532 behind the phase shifts ormal weight of the AC signal of input on the input 142; Resistance 538 and 540 does not change the reversed input terminal that is input to differential amplifier 532 in the phase place of the signal of input on the input 142 after its voltage level dividing potential drop is about 1/2.
When the AC signal of input regulation on the input shown in Figure 55 142, will be applied to voltage Ei dividing potential drop on the input 142 by resistance 538 and resistance 540 is voltage after about 1/2, puts on the reversed input terminal of differential amplifier 532.
On the other hand, when input signal was input to input 142, the signal that occurs on the tie point of resistance 536 and capacitor 534 was input to the in-phase input terminal of differential amplifier 532.Because input signal is input to the end by resistance 536 and capacitor 534 and the CR circuit that constitutes, so, by this CR circuit phase of input signals is moved the in-phase input terminal that signal voltage behind the ormal weight puts on differential amplifier 512.Signal after the difference that differential amplifier 532 output will put on the voltage of 2 input terminals in a manner described with the multiplication factor of regulation is amplified.
Figure 56 is the input and output voltage of expression back level phase-shift circuit 530C and the polar plot that appears at the relation between the voltage on the capacitor etc.
As shown in the drawing, the voltage VC2 that appears at capacitor 534 two ends and the voltage VR2 that appears at resistance 536 two ends be the phase place of 90 ° of phasic differences mutually each other, after the two vector addition, equals input voltage Ei.Therefore, in the amplitude constant of input signal and just under the situation of frequency change, the both end voltage VR2 of the both end voltage VC2 of capacitor 534 and resistance 536 is along the semicircle circumferential variation shown in Figure 56.
In addition, the voltage (the both end voltage VC2 of capacitor 534) that puts on the in-phase input terminal of differential amplifier 532 is subtracted each other with voltage (the both end voltage Ei/2 of the resistance 540) vector that puts on reversed input terminal, can get differential voltage Eo '.This differential voltage Eo ' in the semicircle shown in Figure 56, can be a starting point in order to its central point, the intersection point on circumference is the vector representation of terminal point with voltage VC2 and voltage VR2, and its size equals the radius Ei/2 of semicircle.
With the multiplication factor of regulation with this differential voltage Eo ' amplification after, can get the output voltage Eo of differential amplifier 532.Therefore, in above-mentioned phase-shift circuit 530C, no matter why the frequency of input signal is worth, output voltage Eo is constant, can be used as all pass circuit operation.
In addition, can know from Figure 56 and to find out, because voltage VC2 and voltage VR2 meet at right angle on circumference, so, the phase difference of input voltage Ei and voltage VC2, when frequencies omega changes from 0 to ∞, the variation from 0 ° to 90 °.So the phase-shift phase 10 of the integral body of phase-shift circuit 530C changes between 0 ° to 180 ° according to frequency.
In the manner described above, in each of 2 phase-shift circuit 510C, 530C,, and shown in Figure 54 and Figure 56, under assigned frequency, add up to 360 ° signal by the overall output phase shift amount of 2 phase-shift circuit 510C, 530C respectively with the phase shifts ormal weight.
In addition, the output of back level phase-shift circuit 530C, taken out as the output of tuning circuit 1J from lead-out terminal 192, simultaneously, the output that makes this phase-shift circuit 530C signal after by bleeder circuit 160 is fed back to input side with circuitry phase 550C via feedback resistance 170.Then, with this feedback signal and signal plus by input resistance 174 input, and with the signal after this addition by be input to prime phase-shift circuit 510C with circuitry phase 550.
In addition, by adjusting the gain separately of above-mentioned 2 phase-shift circuit 510C, 530C, can compensate the decay of two phase-shift circuit 510C, 530C shown in Figure 52, bleeder circuit 160 and the loss that in feedback loop, produces, and the loop gain of tuning circuit integral body can be set in below 1.Also can not adjust the gain separately of phase-shift circuit 510C, 530C, and adjust gain, make the value of its maintenance more than 1 with circuitry phase 550.
What take out from the lead-out terminal 192 of tuning circuit 1J is the output that is input to the phase-shift circuit 530C before the bleeder circuit 160, so, the gain that can keep tuning circuit 1J itself, thus can be when carrying out tuning action with the amplitude amplification of signal.
In the tuning circuit shown in Figure 52, when not needing to amplify action, also bleeder circuit 160 can be omitted, and the output of phase-shift circuit 530C is directly fed back to preceding-stage side.Perhaps, making the resistance value of the resistance 162 in the bleeder circuit 160 is minimum value, thereby voltage ratio is set at 1.
[the 13rd variation of tuning circuit]
Tuning circuit 1J shown in Figure 52 comprises the CR circuit though it constitutes in each phase-shift circuit 510C, 530C, also can adopt the phase-shift circuit that the CR circuit is replaced into behind the LR circuit that is made of resistance and inductor to constitute tuning circuit.
Figure 57 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the prime phase-shift circuit 510C of tuning circuit 1J shown in displacement Figure 52 is shown.Phase-shift circuit 510L shown in this figure has the CR circuit that is made of capacitor 514 and variable resistor 516 in the 510C of phase-shift circuit shown in Figure 52 is replaced as structure behind the LR circuit that is made of variable resistor 516 and inductor 517.With inductor 517 capacitor connected in series 519, be used to stop direct current, its impedance sets minimumly under operating frequency, promptly have big electrostatic capacitance.
Figure 57 is the input and output voltage of expression phase-shift circuit 510L and the polar plot of the relation that appears at the voltage on the inductor etc.The time constant of the LR circuit that is made of variable resistor 516 and inductor 517 as supposition is T 1(as the resistance value of establishing variable resistor 516 is that the inductance of R, inductor 517 is L, then T 1=L/R), then the phase-shift phase 11 of the phase-shift circuit 510L shown in Figure 58 is identical with the 1 that above-mentioned formula (6) provides.
And if the phase-shift circuit 510L shown in the phase-shift circuit 510C shown in Figure 52 and Figure 57 is compared the changing in the opposite direction of each phase-shift phase when gate voltage of the FET that forms variable resistor 516 is changed.For example, in phase-shift circuit 510C, the gate voltage that makes variable resistor 516 rises and when voltage VR1 was lowered, tuned frequency changed to high frequency side.On the other hand, in phase-shift circuit 510L, the gate voltage that makes variable resistor 516 rises and when voltage VR1 was lowered, tuned frequency changed to lower frequency side.Therefore, when phase-shift circuit 510C is replaced as phase-shift circuit 510L, in Figure 13, must be with the transposing that is connected of 2 terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit from frequency control circuit 2 and tuning circuit is become oppositely.
Figure 59 is the circuit diagram of another kind of structure that expression comprises the phase-shift circuit of LR circuit, and a kind of possible structure of the prime phase-shift circuit 530C of tuning circuit 1J shown in displacement Figure 52 is shown.Phase-shift circuit 530L shown in this figure has the CR circuit that is made of resistance 536 and capacitor 534 in the 530C of phase-shift circuit shown in Figure 55 is replaced as structure behind the LR circuit that is made of inductor 537 and resistance 536.With inductor 537 capacitor connected in series 539, be used to stop direct current, its impedance sets minimumly under operating frequency, promptly have big electrostatic capacitance.
This phase-shift circuit 530L has the CR circuit that is made of resistance 536 and capacitor 534 in the 530C of phase-shift circuit shown in Figure 55 is replaced into structure behind the LR circuit that is made of inductor 537 and resistance 536.
Figure 60 is the input and output voltage of expression phase-shift circuit 530L and the polar plot of the relation that appears at the voltage on the inductor etc.The time constant of the LR circuit that is made of inductor 537 and resistance 536 as supposition is T 2(as the inductance of establishing inductor 537 be the resistance value of L, resistance 536 be R,, T then 2=L/R), then the phase-shift phase 12 of the phase-shift circuit 530L shown in Figure 60 is identical with the 2 that above-mentioned formula (7) provides.
Like this, phase-shift circuit 530L shown in phase-shift circuit 510L shown in Figure 57 and Figure 59, respectively with the phase-shift circuit 510C shown in Figure 53 or Figure 55,530C equivalence, thereby in the tuning circuit 1J shown in Figure 52, can be respectively with the phase-shift circuit 510C of prime be replaced into the phase-shift circuit 510L shown in Figure 57, will the back level phase-shift circuit 530C be replaced into the phase-shift circuit 530L shown in Figure 59.When the both sides with 2 phase-shift circuit 510C, 530C are replaced into phase-shift circuit 510L, 530L, integrated by the integral body of tuning circuit is carried out, be easy to make tuned frequency to reach high frequency.
In addition, only among 2 phase-shift circuit 510C, the 530C any one is being replaced under the situation of phase-shift circuit 510L or 530L, the integral body that contains the tuning circuit that constitutes LR circuit inductance device, maybe this inductor is removed is being carried out when integrated, can prevent the tuned frequency that causes because of variations in temperature variation, promptly can carry out so-called temperature-compensating.
[the 14th variation of tuning circuit]
Tuning circuit 1J shown in Figure 52 comprises 2 phase-shift circuits that the phase shift direction differs from one another, but also essentially identical 2 phase-shift circuits combination of structure can be constituted tuning circuit.
Figure 61 is the circuit diagram of the another kind of structure of expression tuning circuit.Tuning circuit 1K shown in this figure structurally comprises: negative circuit 580 is used for the AC signal of being imported anti-phase back output; 2 phase-shift circuit 510C, 510C ' add up to 180 ° phase shift by the phase shifts ormal weight of inciting somebody to action input exchange signal separately under assigned frequency; Bleeder circuit 160 is made of the resistance 162 and 164 on the back level of the phase-shift circuit 510C ' that is arranged on the back level; And add circuit, by feedback resistance 170 and input resistance 174 dividing potential drop of bleeder circuit 160 is exported (feedback signal) and the ratio addition of the signal of importing (input signal) with regulation on input terminal 190 respectively.
Prime phase-shift circuit 510C, the phase relation of its detailed structure and input and output, with adopt Figure 53 and Figure 54 to illustrate the same, back level phase-shift circuit 510C ' has the structure that the variable resistor 516 in the prime phase-shift circuit 510C is replaced into the resistance 515 that resistance value fixes.Therefore, under the frequency of regulation, it is 180 ° by the total phase-shift phase of the overall generation of 2 phase-shift circuit 510C, 510C '.
In addition, be connected the negative circuit 580 of the prime of 2 phase-shift circuit 510C, 510C ', be used to make the AC signal of being imported anti-phase, for example realize by earthed-emitter circuit or source ground circuit or with the circuit of operational amplifier and resistance combination.
Like this, under assigned frequency, make 180 ° of phase shifts, and phase place is further reversed, thereby be 360 ° by the total phase-shift phase of the overall generation of these 3 circuit by the negative circuit 580 that is connected in prime by 2 phase-shift circuit 510C, 510C '.
In addition, the output of back level phase-shift circuit 510C ', take out as the output of tuning circuit 1K from lead-out terminal 192, simultaneously, the output that the makes back level phase-shift circuit 510C ' signal after by bleeder circuit 160 is fed back to the input side of negative circuit 580 via feedback resistance 170.Then, with the signal of this feedback and signal plus, and the signal after this addition is input to negative circuit 580 by resistance 174 inputs.
Like this, the output of bleeder circuit 160 is fed back to the input side of negative circuit 580 by feedback resistance 170, and with this feedback signal and the signal plus of importing by resistance 174, simultaneously, adjust the gain of 2 phase-shift circuit 510C, 510C ', the loss that produces by bleeder circuit 160 or at the connecting portion of feedback resistance 170 and input resistance 174 with compensation etc., thus can carry out the tuning action identical and amplify action with the 1J of tuning circuit shown in Figure 52.In addition, also can not adjust phase-shift circuit 510C, 510C ' gain separately, and adjust the gain of negative circuit 580.
In the tuning circuit 1K shown in Figure 61, when not needing to amplify action, also bleeder circuit 160 can be omitted, and the output of phase-shift circuit 510C ' is directly fed back to preceding-stage side.Perhaps, making the resistance value of the resistance 162 in the bleeder circuit 160 is minimum value, thereby voltage ratio is set at 1.
[the 15th variation of tuning circuit]
Figure 62 is the circuit diagram of another variation of expression tuning circuit.Different with Figure 55, structurally comprise the back level phase-shift circuit 530C shown in Figure 52.
Tuning circuit 1L shown in Figure 62 structurally comprises: 2 phase-shift circuit 530C ', 530C add up to 180 ° phase shift by the phase shifts ormal weight of inciting somebody to action input exchange signal separately under assigned frequency; Negative circuit 580 is used so that the phase place of the output signal of back level phase-shift circuit 530C is further reversed; And add circuit, respectively will be from the signal (feedback signal) and the ratio addition of the signal of importing at input terminal 190 (input signal) of negative circuit 580 outputs with regulation by feedback resistance 170 and input resistance 174.
Back level phase-shift circuit 530C, the phase relation of its detailed structure and input and output, with adopt Figure 55 and Figure 56 to illustrate the same, for example, the time constant of supposing the CR circuit that is made of capacitor 534 and resistance 536 is T 2, then frequency is ω=1/T 2The time phase-shift phase 10, be 90 ° along hour hands rotation direction (phase lag direction).
And prime phase-shift circuit 530C ', its basic structure is identical with above-mentioned back level phase-shift circuit 530C, has the resistance in the phase- shift circuit 530C 536 is replaced into the structure that can be changed the variable resistor 535 of resistance value by the control voltage that applies from the outside.Therefore, for example, the time constant of supposing the CR circuit that is made of variable resistor 535 and capacitor 534 is T 2, then frequency is ω=1/T 2The time phase-shift phase 10 ', be 90 ° along the hour hands rotation direction.Therefore, under assigned frequency, it is 180 ° by the total phase-shift phase of the overall generation of 2 phase-shift circuit 530C ', 530C.
Like this, when adopting above-mentioned phase-shift circuit 530C ', 530C, under assigned frequency, also be to make 180 ° of phase shifts by 2 phase-shift circuit 530C ', 530C, and phase place is further reversed, thereby it is 360 ° by the total phase-shift phase of the overall generation of these 3 circuit by the negative circuit 580 that is connected in prime
Therefore, in above-mentioned tuning circuit 1L, the output of bleeder circuit 160 is fed back to the input side of negative circuit 580 by feedback resistance 170, and with this feedback signal and the signal plus of importing by input resistance 174, simultaneously, adjust the gain of 2 phase- shift circuit 530C, 530C ', the loss that produces by bleeder circuit 160 or at the connecting portion of feedback resistance 170 and input resistance 174 with compensation etc., and the loop gain of feedback loop is set in below 1, thereby can carries out the tuning action identical and amplify action with the 1K of tuning circuit shown in Figure 61 etc.
In addition, tuning circuit 1K, the 1L shown in Figure 61 and Figure 62, the phase-shift circuit cascade that inside is comprised the CR circuit connects, but also can comprise the LR circuit at least one phase-shift circuit inside.
Specifically, in the tuning circuit 1K shown in Figure 61, prime phase-shift circuit 510C is replaced into the phase-shift circuit 510L shown in Figure 57, or will back level phase-shift circuit 510C ' be replaced into the phase-shift circuit 510L ' that adopts behind the variable resistor 516 that the fixing resistance of resistance value 515 replaces in the phase-shift circuit 510L shown in Figure 57.Perhaps, the both sides with 2 phase-shift circuit 510C, 510C ' are replaced into above-mentioned phase-shift circuit 510L, 510L '.
In addition, in the tuning circuit 1L shown in Figure 62, prime phase-shift circuit 530C ' is replaced into the phase-shift circuit 530L ' that adopts behind the resistance 536 that variable resistor 535 replaces in the phase-shift circuit 530L shown in Figure 59, or a back level phase-shift circuit 530C is replaced into the phase-shift circuit 530L shown in Figure 59.Perhaps, the both sides with phase-shift circuit 530C ', 530C are replaced into above-mentioned phase-shift circuit 530L ', 530L.
But, when the phase-shift circuit 510L that the prime phase-shift circuit 510C shown in Figure 61 is replaced into shown in Figure 57, or when the prime phase-shift circuit 530C ' shown in Figure 62 is replaced into phase-shift circuit after resistance with the phase-shift circuit 530L shown in Figure 59 changes to variable resistor 535, because changing in the opposite direction of each phase-shift phase when gate voltage of the variable-resistance FET of formation changes, so, in Figure 13, must be with 2 lead-out terminals and the tristate buffer 700 of trigger 63,702 connection transposing, or with 2 tristate buffers 700, the link of 702 output is changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit from frequency control circuit 2 and tuning circuit is become oppositely.
In tuning circuit 1K, the 1L shown in Figure 61 and Figure 62, when not needing to amplify action, also bleeder circuit 160 can be omitted, and the output that phase-shift circuit 510C ' waits is directly fed back to preceding-stage side.Perhaps, making the resistance value of the resistance 162 in the bleeder circuit 160 is minimum value, thereby voltage ratio is set at 1.
Simultaneously, above-mentioned various tuning circuit 1J, 1K, 1L, structurally comprise negative circuit and 2 phase-shift circuits or with circuitry phase and 2 phase-shift circuits, and to make the phase-shift phase of total under assigned frequency be 360 ° by connecting overall behind 3 circuit when being conceived to phase shift, thereby the tuning action that can stipulate.Therefore, when only being conceived to phase-shift phase, which perhaps is linked in sequence above-mentioned 3 circuit by what kind of in two phase-shift circuits of prime use, has the degree of freedom to a certain degree, can determine the order of connection as required.
[other variation of J.]
Simultaneously, at the various mechanical tuning devices shown in Fig. 1 etc., variable resistor 116 grades in the phase-shift circuit in the phase-shift circuit that constitutes tuning circuit are formed with junction type FET, but also can adopt other elements to constitute variable resistor.
To be expression be replaced into the circuit diagram of the structure of the variable resistor 126 that the FET with the MOS type forms with the variable resistor 116 in the phase-shift circuit 110C shown in Figure 3 to Figure 63.Like this, the raceway groove that forms between leaking of the source that can be used in the FET of MOS type is as resistive element.In this case, the control voltage that puts on grid by change can make the channel resistance of this FET change, so, the tuned frequency of tuning circuit 1 grade is changed arbitrarily within the specific limits.
In addition, in above-mentioned each tuning circuit, the resistance value of the variable resistor 116 by changing prime phase-shift circuit inside changes tuned frequency, but also this variable resistor can be replaced into fixed resistance, resistance 136 grades that simultaneously will back level phase-shift circuit inside are replaced into the variable resistor that is formed by junction type or MOS type FET, and make overall tuned frequency change by the control voltage that change puts on this FET grid.But the shift direction when control voltage changes becomes when reverse, in Figure 13, must be with the transposing that is connected of 2 terminals with the tristate buffer 700,702 of trigger 63, or the link of the output of 2 tristate buffers 700,702 changed each other, promptly must do some changes, so that the change direction of the tuned frequency of the change direction of the control voltage that applies to tuning circuit 1 from frequency control circuit 2 and tuning circuit 1 is become oppositely.
Perhaps, also can variable resistor be set respectively in prime and level phase-shift circuit inside, back.In this case owing to can change the phase-shift phase separately of 2 phase-shift circuits simultaneously, so, have can with overall tuned frequency variable quantity, be the excursion of tuned frequency set very big advantage.Further, in Fig. 2 etc., also can be with the front and back position exchange of 2 phase-shift circuits in the tuning circuit.
In addition, above-mentioned phase-shift circuit 110C etc., by the resistance value that changes variable resistor 116 grades that are connected in series with capacitor 114 grades phase-shift phase is changed, thereby change overall tuned frequency, but also can change overall tuned frequency by the electrostatic capacitance that changes capacitor 114 grades.
For example, be replaced into variable-capacitance element by capacitor 114 grades that will be comprised at least one of 2 phase-shift circuits and change its electrostatic capacitance, the phase-shift phase of each phase-shift circuit is changed, thereby change tuned frequency.More particularly, above-mentioned variable-capacitance element can be by changing the variable capacitance diode that is applied to the reverse bias voltage between the anode negative electrode, maybe can forming by the FET that grid voltage changes grid capacitance.And be to make the reverse bias voltage that puts on above-mentioned variable-capacitance element variable, the capacitor that the prevention direct current need only be used and this variable-capacitance element are connected in series and get final product.
In addition, in Fig. 2 etc., the variable resistor 116 in the phase-shift circuit 110C is formed by FET, but also can be with the formation of the element beyond FET variable resistor 116.For example, Figure 64 is the circuit diagram of the example when adopting FET element in addition as the variable resistor in phase-shift circuit 110C or the 130C.Structure shown in this figure is, the phase-shift circuit 110C ' that tuning circuit 1 is comprised structurally comprises the CdS optical coupler, simultaneously, between voltage combiner circuit 7E that frequency control circuit 2 is comprised and this phase-shift circuit 110C ', be connected and control the voltage-to-current translation circuit 200 that voltage transformation is a Control current.
Phase-shift circuit 110C ' shown in Figure 64 has the structure that the variable resistor 116 with FET formation in the phase-shift circuit 110C shown in Figure 3 is replaced into the CdS optical coupler 177 that is made of CdS optical sensor and light-emitting diode.The CdS transducer that this optical coupler 177 is comprised, the more little characteristic of the many more resistance values of luminous quantity with light-emitting diode, so, this CdS optical coupler 177 can be able to be accompanyed or follow the Control current that the outside applies as its resistance value and the variable resistor that changes used.
Voltage combiner circuit 7E shown in Figure 64 has the structure after voltage combiner circuit 7 shown in Figure 13 partly changed, and its difference is that the biasing circuits that are made of variable resistor 706 and resistance 722 in the voltage combiner circuit 7 of Figure 13 are removed.
In addition, the voltage-to-current translation circuit 200 shown in Figure 64 structurally comprises: operational amplifier 204, on its reversed input terminal, promptly control voltage by the output of resistance 202 input voltage combiner circuit 7E; And variable resistor 206, be used to produce variable bias voltage.
Operational amplifier 204 is being connected the light-emitting diode in the above-mentioned optical coupler 177, in-phase input terminal ground connection between lead-out terminal and reversed input terminal.Therefore, when the output voltage (control voltage) of voltage combiner circuit 7E when determining, flow through light-emitting diode in the optical coupler 177 by the rated current of the resistance ratio of resistance 202 and variable resistor 206 decision, make the CdS optical sensor relative have the certain resistance value corresponding with the luminous quantity of light-emitting diode with this light-emitting diode.
Therefore, by reducing the output voltage of voltage combiner circuit 7E, the current value that flows through light-emitting diode is reduced and reduce luminous quantity, the resistance value that the CdS optical sensor is had increases, thereby makes the tuned frequency reduction of tuning circuit 1.On the contrary, by the output voltage of boosted voltage combiner circuit 7E, the current value that flows through light-emitting diode is increased and the increase luminous quantity, the resistance value that the CdS optical sensor is had reduces, thereby the tuned frequency of tuning circuit 1 is raise.This relation is identical with the relation of variable resistor that is formed by above-mentioned FET and control voltage, can make the tuned frequency of tuning circuit 1 consistent with the frequency of input signal by identical control program.
Like this, by adopting optical coupler 177, also can constitute the tuning circuit of the mechanical tuning device of realizing above-mentioned example as variable resistor.When adopting optical coupler 177 as variable resistor, no matter what value is variable-resistance both end voltage etc. be, always can obtain certain resistance value, so have the advantage of the little tuning output that is easy to obtain to distort.But, because that the integral body that can not will comprise the tuning circuit 1 of optical coupler is carried out on Semiconductor substrate is integrated, so have only optical coupler 177 as single parts with wiring such as connecting lines.
In addition, in above-mentioned example, constitute tuning circuit 1～1E by the phase-shift circuit 110C that adopts operational amplifier etc., thereby can realize high stability, but in such usage such as phase-shift circuit 110C that resembles this example, on offset voltage or voltage gain and do not require so high performance, so, also can use differential amplifier to replace operational amplifier in each phase-shift circuit with regulation multiplication factor.
Figure 65 is the circuit diagram of in the structure that adopts operational amplifier the needed part of the action of phase-shift circuit being extracted out, and whole conduct has the differential amplifier of regulation multiplication factor and operates.Differential amplifier shown in this figure comprises the differential input level 100 that is made of FET, this differential input level 100 is supplied with the constant-current circuit 102 of constant currents, constant-current circuit 102 supplied with biasing circuit 104, and the output amplifier 106 that is connected with differential input level 100 of regulation bias voltages.As shown in the drawing, save the multistage amplifier circuit that is used to obtain voltage gain that the actual operation amplifier is comprised, thereby can make the designs simplification of differential amplifier, and can realize wide frequency band.Like this,, can improve the upper limit of operating frequency, so can improve the tuned frequency upper limit of tuning circuit 1 grade of the differential amplifier formation that adopts this form by carrying out the simplification of circuit.
In addition, the present invention is not limited to above-mentioned various example, can implement various distortion in basic essential scope of the present invention.
For example, figure 2 illustrates the tuning circuit 1 of detailed structure etc., adopt feedback resistance 170 as the feedback impedance element, adopt input resistance 174 as the input impedance element, but owing to do not change phase relation as long as can will be input to the signal plus of each element, so can replace resistance to form feedback impedance element and input impedance element with capacitor, or also can and adjust the real part of impedance and the ratio of imaginary part branch simultaneously with combinations such as resistance and electric capacity.
At least one resistance in feedback resistance 170 and the input resistance 174 can also constitute with variable resistor, thereby can make the tuning frequency bandwidth of tuning circuit 1 grade variable.
In addition, in phase-shift circuit 110C shown in Figure 2 etc., variable resistor 116 is made of a FET, but also the FET of the FET of p raceway groove and n raceway groove can be connected in parallel and constitute a variable resistor.Like this, by 2 FET combinations are constituted variable resistor, owing to improving the nonlinear area of FET, so can reduce the distortion of tuning output.
Below be illustrated in the invention put down in writing in each claim and the corresponding relation of accompanying drawing, and the corresponding relation of the mark in the resistance of in each claim, being put down in writing etc. and the specification.
(1) tuning circuit of claim 18, corresponding to Figure 33,34,35.The 1st, 2,3 resistance in claim 18 and the resistance of Ge Tu corresponding as follows.
The 1st resistance → resistance 118,138;
The 2nd resistance → resistance 120,140;
The 3rd resistance → variable resistor 116,135, resistance 115,136.
(2) tuning circuit of claim 26, corresponding to Fig. 2,30,32.The 1st, 2,3 resistance in claim 26 and the resistance of Ge Tu corresponding as follows.
The 1st resistance → resistance 118,138;
The 2nd resistance → resistance 120,140;
The 3rd resistance → variable resistor 116, resistance 136.
(3) tuning circuit of claim 34, corresponding to Figure 34,35,36.The 1st～4 resistance in claim 34 and the resistance of Ge Tu corresponding as follows.
The 1st resistance → resistance 118 ', 138 ';
The 2nd resistance → resistance 120 ', 140 ';
The 3rd resistance → resistance 119,139;
The 4th resistance → variable resistor 116, resistance 136.
(4) tuning circuit of claim 42, corresponding to Figure 41,46,48.The resistance of the 1st resistance in claim 42 etc. and each figure etc. corresponding as follows.
The 1st resistance → variable resistor 416, resistance 436;
Converting means → FET412, resistance 418,420; Or FET432, resistance 438,440.
(5) tuning circuit of claim 48, corresponding to Figure 50,51.The corresponding relation of the resistance of the 1st resistance in claim 48 etc. and each figure etc. is as follows.
The 1st resistance → variable resistor 416, resistance 436.
(6) tuning circuit of claim 54, corresponding to Figure 52,57,59.The corresponding relation of the resistance of the 1st resistance in claim 54 etc. and each figure etc. is as follows.
The 1st resistance → resistance 518,538;
The 2nd resistance → resistance 520,540;
The 3rd resistance → variable resistor 516, resistance 536.
(7) tuning circuit of claim 60 is corresponding to each figure of aforesaid right requirement 26,34,42,48,54.Input impedance element in the claim 60 and the corresponding relation of feedback impedance element and Ge Tu are as follows.
Input impedance element → resistance 174;
Feedback impedance element → resistance 170.
Application possibility on the industry
As mentioned above, tuning manner of the present invention is owing to carry out FEEDBACK CONTROL to the tuned frequency of tuning circuit With the frequency input signal of elimination tuning circuit and the deviation of tuned frequency, so can make reliably accent Humorous frequency is consistent with the frequency of input signal. Therefore, with the tuning circuit over all Integration time, even every system There is discrete discrepancy in the chip that becomes, and tuning characteristic does not have deviation yet. In addition, even determine tuned frequency The parameter of each element changes with temperature etc., and tuned frequency does not also change, so also be suitable for integrated Change.

Claims (61)

1. tuning control manner, have: tuning circuit, comprise wildcard-filter style phase-shift circuit that 2 cascades connect, and the output of above-mentioned phase-shift circuit that will the back level feed back to the input side of the above-mentioned phase-shift circuit of prime, will be input to the add circuit of the above-mentioned phase-shift circuit of prime after above-mentioned feedback signal and the input signal addition simultaneously as feedback signal, and the signal of close assigned frequency is passed through;
It is characterized in that also having, frequency control circuit, when above-mentioned tuning circuit having been imported the signal of the close afore mentioned rules frequency of its frequency, according to the phase difference between the input/output signal of above-mentioned tuning circuit, make the tuned frequency of above-mentioned tuning circuit consistent with the frequency of the input signal of above-mentioned tuning circuit.
2. tuning control manner according to claim 1, it is characterized in that: at least one of above-mentioned 2 phase-shift circuits that above-mentioned tuning circuit comprised can change phase-shift phase according to the control signal from the output of said frequencies control circuit, when the tuned frequency of the frequency of the signal that is input to above-mentioned tuning circuit and above-mentioned tuning circuit not simultaneously, by changing at least one phase-shift phase of above-mentioned 2 phase-shift circuits, make above-mentioned tuned frequency consistent with the frequency of the input signal of above-mentioned tuning circuit.
3. tuning control manner according to claim 2, it is characterized in that: the said frequencies control circuit has: circuit of synchronous rectification, according to the contrast signal synchronous, the input signal of above-mentioned tuning circuit is carried out synchronous rectification with the output signal of above-mentioned tuning circuit; And control signal generative circuit, output according to above-mentioned circuit of synchronous rectification detects the phase difference between the input/output signal of above-mentioned tuning circuit, and output makes the control signal of the tuned frequency of above-mentioned tuning circuit towards the direction variation of eliminating this phase difference.
4. tuning control manner according to claim 3 is characterized in that: above-mentioned circuit of synchronous rectification has: contrast signal generative circuit, the synchronous contrast signal of output signal of output and above-mentioned tuning circuit; And switch, with above-mentioned contrast signal the input signal of above-mentioned tuning circuit is passed through or cut-out.
5. tuning control manner according to claim 4, it is characterized in that: above-mentioned contrast signal generative circuit comprises voltage comparator, compare by voltage level and assigned voltage value, export the square wave corresponding as above-mentioned contrast signal with this comparative result with the output signal of above-mentioned tuning circuit; 2 voltage levels that above-mentioned switch has above-mentioned square wave make the input signal of above-mentioned tuning circuit pass through when on-state respectively as on-state and off-state.
6. tuning control manner according to claim 3, it is characterized in that: above-mentioned control signal generative circuit has: pulse conversion circuit, according to the output of above-mentioned circuit of synchronous rectification, output has the signal of the corresponding pulse duration of phase difference between input/output signal with above-mentioned tuning circuit; The polarity discriminating circuit according in the input/output signal of above-mentioned tuning circuit any one, is judged the polarity of above-mentioned phase difference; And voltage combiner circuit, be used to produce the proportional component of voltage of pulse duration with the signal of exporting from above-mentioned pulse conversion circuit, simultaneously, according to the judged result of above-mentioned polarity discriminating circuit, by with this component of voltage and assigned voltage addition or subtract each other that to control voltage synthetic; To export as above-mentioned control signal by the synthetic above-mentioned control voltage of above-mentioned voltage combiner circuit.
7. tuning control manner according to claim 6, it is characterized in that: above-mentioned pulse conversion circuit comprises voltage comparator, by will comparing the signal that output has the pulse duration corresponding with this comparative result from voltage level and the assigned voltage value that the synchronous rectification of above-mentioned circuit of synchronous rectification output is exported.
8. tuning control manner according to claim 6 is characterized in that: above-mentioned polarity discriminating circuit, according to the rising of above-mentioned pulse conversion circuit output signal or the synchronous sequential that descends, carry out the polarity of above-mentioned phase difference according to above-mentioned contrast signal and judge.
9. tuning control manner according to claim 8, it is characterized in that: above-mentioned polarity discriminating circuit comprises 2 grades of triggers that cascade connects, with the rising of above-mentioned pulse conversion circuit output signal or the synchronously maintenance logic level corresponding with above-mentioned contrast signal that descend.
10. tuning control manner according to claim 9, it is characterized in that: above-mentioned polarity discriminating circuit also comprises the delay element of the output signal delay stipulated time that makes above-mentioned pulse conversion circuit, according to the rising of above-mentioned pulse conversion circuit output signal or descend, carry out the polarity of above-mentioned phase difference and judge according to the afore mentioned rules sequential of time of delay.
11. tuning control manner according to claim 6 is characterized in that: above-mentioned voltage combiner circuit has: 2 opening and closing devices according to the judged result of above-mentioned polarity discriminating circuit, pass through or cut-out the output signal of above-mentioned pulse conversion circuit; And the voltage adding device, according to the pulse duration of the signal of any one output from above-mentioned 2 opening and closing devices, carry out the addition of voltage, and, carry out subtracting each other of voltage according to the pulse duration of the signal of wherein another output.
12. tuning control manner according to claim 11, it is characterized in that: above-mentioned 2 opening and closing devices have the 1st input terminal, the 2nd input terminal respectively, reach lead-out terminal, the signal of the judged result of the above-mentioned polarity discriminating circuit of input expression on above-mentioned the 1st input terminal, the output signal of the above-mentioned pulse conversion circuit of input on above-mentioned the 2nd input terminal, according to the voltage level of above-mentioned the 1st input terminal, export its logic level and the identical or different signal of above-mentioned the 2nd input terminal from above-mentioned lead-out terminal.
13. tuning control manner according to claim 12 is characterized in that: above-mentioned 2 opening and closing devices respectively by tristate buffer, analog switch, and gate in any one constitute.
14. tuning control manner according to claim 11 is characterized in that: above-mentioned voltage adding device comprises the difference channel that the difference of above-mentioned 2 opening and closing devices output voltage is separately carried out computing.
15. tuning control manner according to claim 14 is characterized in that: above-mentioned voltage adding device also comprises and is used for filter circuit that the high fdrequency component of the output of above-mentioned difference channel is removed.
16. tuning control manner according to claim 3 is characterized in that: at the back level connection low pass filter of above-mentioned circuit of synchronous rectification, when above-mentioned tuning circuit is transfused to the AM ripple, from above-mentioned low pass filter output AM rectified signal.
17. tuning control manner according to claim 3, it is characterized in that: the said frequencies control circuit has high frequency and removes circuit, be used for will be relevant with the above-mentioned control signal that generates at above-mentioned control signal generative circuit the assigned frequency that signal contained more than high fdrequency component remove, when above-mentioned tuning circuit is imported the FM ripple, remove circuit output FM rectified signal from above-mentioned high frequency.
18. tuning control manner according to claim 2, it is characterized in that: at least one of above-mentioned 2 phase-shift circuits that above-mentioned tuning circuit comprised comprises: differential amplifier, one end of the 1st resistance is connected with reversed input terminal, and by above-mentioned the 1st resistance input exchange signal; The 2nd resistance is connected between the reversed input terminal of the output of above-mentioned differential amplifier and above-mentioned differential amplifier; And series circuit, constitute by the reactance component and the 3rd resistance of capacitor or inductor, can change time constant according to above-mentioned control signal, and be connected with the other end of above-mentioned the 1st resistance; The connecting portion of above-mentioned the 3rd resistance and above-mentioned reactance component is connected with the in-phase input terminal of above-mentioned differential amplifier.
19. tuning control manner according to claim 18, it is characterized in that: above-mentioned tuning circuit has the phase place that does not change the AC signal of being imported and the same circuitry phase of exporting, in the above-mentioned part that is plugged on the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form with circuitry phase; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 360 ° frequency passes through.
20. tuning control manner according to claim 18, it is characterized in that: above-mentioned tuning circuit has the negative circuit of exporting after the phasing back that makes the AC signal of being imported, and above-mentioned negative circuit is plugged in the part of the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 180 ° frequency passes through.
21. tuning control manner according to claim 18 is characterized in that: the prime of 2 phase-shift circuits that connect in above-mentioned cascade is inserted the follower circuit that is made of transistor.
22. tuning control manner according to claim 18 is characterized in that: in the part of the feedback loop that 2 phase-shift circuits that connected by above-mentioned cascade form, insert bleeder circuit; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned bleeder circuit and export as harmonic ringing.
23. tuning control manner according to claim 18, it is characterized in that: at least one of resistance that constitutes the above-mentioned series circuit in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
24. tuning control manner according to claim 18 is characterized in that: above-mentioned differential amplifier is an operational amplifier.
25. tuning control manner according to claim 18 is characterized in that: with component parts whole formation on Semiconductor substrate.
26. tuning control manner according to claim 2, it is characterized in that: at least one of 2 phase-shift circuits that above-mentioned tuning circuit comprised comprises: differential amplifier, one end of the 1st resistance is connected with reversed input terminal, and by above-mentioned the 1st resistance input exchange signal; The 1st bleeder circuit is connected in the lead-out terminal of above-mentioned differential amplifier; The 2nd resistance is connected between the reversed input terminal of the output of above-mentioned the 1st bleeder circuit and above-mentioned differential amplifier; And series circuit, constitute by the reactance component and the 3rd resistance of capacitor or inductor, can change time constant according to above-mentioned control signal, and be connected with the other end of above-mentioned the 1st resistance; The connecting portion of above-mentioned the 3rd resistance and above-mentioned reactance component is connected with the in-phase input terminal of above-mentioned differential amplifier.
27. tuning control manner according to claim 26, it is characterized in that: above-mentioned tuning circuit has the phase place that does not change the AC signal of being imported and the same circuitry phase of exporting, in the above-mentioned part that is plugged on the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form with circuitry phase; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 360 ° frequency passes through.
28. tuning control manner according to claim 26, it is characterized in that: above-mentioned tuning circuit has the negative circuit of exporting after the phasing back that makes the AC signal of being imported, and above-mentioned negative circuit is plugged in the part of the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 180 ° frequency passes through.
29. tuning control manner according to claim 26 is characterized in that: the prime of 2 phase-shift circuits that connect in above-mentioned cascade is inserted the follower circuit that is made of transistor.
30. tuning control manner according to claim 26 is characterized in that: in the part of the feedback loop that 2 phase-shift circuits that connected by above-mentioned cascade form, insert the 2nd bleeder circuit; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned the 2nd bleeder circuit and export as harmonic ringing.
31. tuning control manner according to claim 26, it is characterized in that: at least one of resistance that constitutes the above-mentioned series circuit in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
32. tuning control manner according to claim 26 is characterized in that: above-mentioned differential amplifier is an operational amplifier.
33. tuning control manner according to claim 26 is characterized in that: with component parts whole formation on Semiconductor substrate.
34. tuning control manner according to claim 2, it is characterized in that: at least one of above-mentioned 2 phase-shift circuits that above-mentioned tuning circuit comprised comprises: differential amplifier, one end of the 1st resistance is connected with reversed input terminal, and by above-mentioned the 1st resistance input exchange signal; The 2nd resistance is connected between the reversed input terminal and lead-out terminal of above-mentioned differential amplifier; The 3rd resistance, an end is connected with the reversed input terminal of above-mentioned differential amplifier, other end ground connection; And series circuit, constitute by the reactance component and the 4th resistance of capacitor or inductor, can change time constant according to above-mentioned control signal, and be connected with the other end of above-mentioned the 1st resistance; The connecting portion of above-mentioned the 4th resistance and above-mentioned reactance component is connected with the in-phase input terminal of above-mentioned differential amplifier.
35. tuning control manner according to claim 34, it is characterized in that: above-mentioned tuning circuit has the phase place that does not change the AC signal of being imported and the same circuitry phase of exporting, in the above-mentioned part that is plugged on the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form with circuitry phase; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 360 ° frequency passes through.
36. tuning control manner according to claim 34, it is characterized in that: above-mentioned tuning circuit has the negative circuit of exporting after the phasing back that makes the AC signal of being imported, and above-mentioned negative circuit is plugged in the part of the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 180 ° frequency passes through.
37. tuning control manner according to claim 34 is characterized in that: the prime of 2 phase-shift circuits that connect in above-mentioned cascade is inserted the follower circuit that is made of transistor.
38. tuning control manner according to claim 34 is characterized in that: in the part of the feedback loop that 2 phase-shift circuits that connected by above-mentioned cascade form, insert bleeder circuit; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned bleeder circuit and export as harmonic ringing.
39. tuning control manner according to claim 34, it is characterized in that: at least one of resistance that constitutes the above-mentioned series circuit in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
40. tuning control manner according to claim 34 is characterized in that: above-mentioned differential amplifier is an operational amplifier.
41. tuning control manner according to claim 34 is characterized in that: with component parts whole formation on Semiconductor substrate.
42. tuning control manner according to claim 2, it is characterized in that: above-mentioned tuning circuit has the phase place that does not change the AC signal of being imported and the same circuitry phase of exporting, in the above-mentioned part that is plugged on the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form with circuitry phase; At least one of above-mentioned 2 phase-shift circuits comprises: converting means is transformed to homophase and anti-phase AC signal with the AC signal of being imported; Series circuit is made of the reactance component and the 1st resistance of capacitor or inductor, can change time constant according to above-mentioned control signal; And synthesizer, make by the end of an AC signal after the above-mentioned converting means conversion by above-mentioned series circuit, the other end of another AC signal by above-mentioned series circuit synthesized.
43. according to the described tuning control manner of claim 42, it is characterized in that: the signal that above-mentioned tuning circuit only makes the phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 360 ° frequency passes through.
44., it is characterized in that: in the part of 2 phase-shift circuits that connect by above-mentioned cascade and the circuit-formed feedback loop of above-mentioned homophase, insert bleeder circuit according to the described tuning control manner of claim 42; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned bleeder circuit and export as harmonic ringing.
45. according to the described tuning control manner of claim 42, it is characterized in that: the above-mentioned converting means in above-mentioned 2 phase-shift circuits comprises transistor, on above-mentioned transistorized source electrode and drain electrode or emitter and collector, be connected the 2nd resistance that its resistance value equates substantially respectively, input exchange signal on above-mentioned transistorized grid or base stage is between leak in above-mentioned transistorized source or connect and compose the above-mentioned reactance component and above-mentioned the 1st resistance of above-mentioned series circuit between the emitter collector electrode.
46. according to the described tuning control manner of claim 42, it is characterized in that: at least one of above-mentioned the 1st resistance in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
47., it is characterized in that: with component parts whole formation on Semiconductor substrate according to the described tuning control manner of claim 42.
48. tuning control manner according to claim 2, it is characterized in that: above-mentioned tuning circuit has the negative circuit of exporting after the phasing back that makes the AC signal of being imported, and above-mentioned negative circuit is plugged in the part of the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form; At least one of above-mentioned 2 phase-shift circuits comprises: converting means is transformed to homophase and anti-phase AC signal with the AC signal of being imported; Series circuit is made of the reactance component and the 1st resistance of capacitor or inductor, can change time constant according to above-mentioned control signal; And synthesizer, make by the end of an AC signal after the above-mentioned converting means conversion by above-mentioned series circuit, the other end of another AC signal by above-mentioned series circuit synthesized.
49. according to the described tuning control manner of claim 48, it is characterized in that: the signal that above-mentioned tuning circuit only makes the phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 180 ° frequency passes through.
50., it is characterized in that: in the part of the feedback loop that 2 phase-shift circuits and above-mentioned negative circuit by above-mentioned cascade connection form, insert bleeder circuit according to the described tuning control manner of claim 48; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned bleeder circuit and export as harmonic ringing.
51. according to the described tuning control manner of claim 48, it is characterized in that: the above-mentioned converting means in above-mentioned 2 phase-shift circuits comprises transistor, on above-mentioned transistorized source electrode and drain electrode or emitter and collector, be connected the 2nd resistance that its resistance value equates substantially respectively, input exchange signal on above-mentioned transistorized grid or base stage is between leak in above-mentioned transistorized source or connect and compose the above-mentioned reactance component and above-mentioned the 1st resistance of above-mentioned series circuit between the emitter collector electrode.
52. according to the described tuning control manner of claim 48, it is characterized in that: at least one of above-mentioned the 1st resistance in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
53., it is characterized in that: with component parts whole formation on Semiconductor substrate according to the described tuning control manner of claim 48.
54. tuning control manner according to claim 2 is characterized in that: at least one of above-mentioned 2 phase-shift circuits that above-mentioned tuning circuit comprised comprises: the 1st series circuit, and the 1st and the 2nd resistance that is equated substantially by resistance value constitutes; The 2nd series circuit is made of the reactance component and the 3rd resistance of capacitor or inductor; And differential amplifier, the current potential of the tie point of the 1st and the 2nd resistance that constitutes above-mentioned the 1st series circuit is amplified with the difference of the current potential of the tie point of above-mentioned reactance component that constitutes above-mentioned the 2nd series circuit and the 3rd resistance and export with the multiplication factor of regulation; In the end difference input exchange signal of the above-mentioned the 1st and the 2nd series circuit, above-mentioned the 2nd series circuit can change time constant according to above-mentioned control signal.
55. according to the described tuning control manner of claim 54, it is characterized in that: above-mentioned tuning circuit has the phase place that does not change the AC signal of being imported and the same circuitry phase of exporting, in the above-mentioned part that is plugged on the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form with circuitry phase; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 360 ° frequency passes through.
56. according to the described tuning control manner of claim 54, it is characterized in that: above-mentioned tuning circuit has the negative circuit of exporting after the phasing back that makes the AC signal of being imported, and above-mentioned negative circuit is plugged in the part of the feedback loop that 2 phase-shift circuits being connected by above-mentioned cascade form; Above-mentioned tuning circuit, the signal that only makes phase-shift phase near the overall generation of 2 phase-shift circuits that connected by above-mentioned cascade add up to 180 ° frequency passes through.
57., it is characterized in that: in the part of the feedback loop that 2 phase-shift circuits that connected by above-mentioned cascade form, insert bleeder circuit according to the described tuning control manner of claim 54; Above-mentioned tuning circuit will be input to the AC signal of above-mentioned bleeder circuit and export as harmonic ringing.
58. according to the described tuning control manner of claim 54, it is characterized in that: at least one of resistance that constitutes the above-mentioned the 1st and the 2nd series circuit in 2 phase-shift circuits that above-mentioned cascade connects, form by variable resistor, voltage level according to above-mentioned control signal changes above-mentioned variable-resistance resistance value, can change the tuned frequency of above-mentioned tuning circuit.
59., it is characterized in that: with component parts whole formation on Semiconductor substrate according to the described tuning control manner of claim 54.
60. tuning control manner according to claim 2 is characterized in that: above-mentioned tuning circuit comprises the input impedance element of at one end importing above-mentioned input signal, and at one end imports the feedback impedance element of above-mentioned feedback signal; Above-mentioned add circuit is with the signal plus of the other end of the signal of the other end of above-mentioned input impedance element and above-mentioned feedback impedance element.
61., it is characterized in that:, change the frequency bandwidth of above-mentioned tuning circuit by changing the ratio of above-mentioned input impedance element and the component parameters of above-mentioned feedback impedance element according to the described tuning control manner of claim 60.
CN96198160A 1995-11-09 1996-04-23 Tuning control manner Expired - Fee Related CN1113463C (en)

Applications Claiming Priority (24)

Application Number Priority Date Filing Date Title
JP317227/1995 1995-11-09
JP31756795 1995-11-09
JP317393/95 1995-11-09
JP317566/1995 1995-11-09
JP317228/95 1995-11-09
JP317567/1995 1995-11-09
JP317566/95 1995-11-09
JP31739395 1995-11-09
JP317227/95 1995-11-09
JP317393/1995 1995-11-09
JP31722895 1995-11-09
JP317567/95 1995-11-09
JP317228/1995 1995-11-09
JP31756695 1995-11-09
JP31722795 1995-11-09
JP34665795 1995-12-13
JP346657/95 1995-12-13
JP346657/1995 1995-12-13
JP18152/96 1996-01-08
JP18152/1996 1996-01-08
JP1815296 1996-01-08
JP38880/1996 1996-02-01
JP38880/96 1996-02-01
JP3888096 1996-02-01

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CN1113463C true CN1113463C (en) 2003-07-02

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WO (1) WO1997017760A1 (en)

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WO2005119206A1 (en) * 2004-06-02 2005-12-15 Japan Science And Technology Agency Method and device for controlling photo-excitation q value of vibrator
CN110380687B (en) * 2019-08-23 2024-06-18 无锡嘉硕科技有限公司 Multifunctional automatic correction and compensation machine for temperature frequency drift of crystal oscillator

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JPS6290016A (en) * 1986-06-25 1987-04-24 Nippon Columbia Co Ltd Frequency characteristic correction circuit
JPH03178205A (en) * 1989-12-07 1991-08-02 Matsushita Electric Ind Co Ltd Phase shift type cr oscillator
JPH0575387A (en) * 1991-09-17 1993-03-26 Sanyo Electric Co Ltd Variable delay circuit
JPH05183406A (en) * 1991-12-27 1993-07-23 Nec Eng Ltd Automatic phase correction circuit
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KR19990037687A (en) 1999-05-25
KR100350399B1 (en) 2002-12-18
AU5348296A (en) 1997-05-29
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HK1015978A1 (en) 1999-10-22
JP3764484B2 (en) 2006-04-05

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