WO1997018625A1 - Modulateur fm - Google Patents

Modulateur fm Download PDF

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Publication number
WO1997018625A1
WO1997018625A1 PCT/JP1996/001706 JP9601706W WO9718625A1 WO 1997018625 A1 WO1997018625 A1 WO 1997018625A1 JP 9601706 W JP9601706 W JP 9601706W WO 9718625 A1 WO9718625 A1 WO 9718625A1
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WIPO (PCT)
Prior art keywords
circuit
phase shift
phase
signal
resistor
Prior art date
Application number
PCT/JP1996/001706
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English (en)
Japanese (ja)
Inventor
Takeshi Ikeda
Akira Okamoto
Original Assignee
Takeshi Ikeda
Akira Okamoto
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Takeshi Ikeda, Akira Okamoto filed Critical Takeshi Ikeda
Priority to AU61378/96A priority Critical patent/AU6137896A/en
Publication of WO1997018625A1 publication Critical patent/WO1997018625A1/fr

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/10—Angle modulation by means of variable impedance

Definitions

  • the present invention relates to an FM modulator that FM-modulates a ⁇ signal input from the outside and sends it out.
  • the FM modulation circuit is generally configured using an LC oscillator that generates a sine wave with little distortion.
  • LC oscillators for example, Colpitts type oscillators.
  • the capacity of the LC resonance circuit contained in the oscillator is composed of varicaps (variable capacitance diodes), and the capacitance is the voltage level of the FM modulation signal. FM modulation is performed by changing the bell according to the fluctuation.
  • the present invention has been conceived in order to solve such a problem, and a purpose thereof is to provide an FM modulator having a simple circuit configuration.
  • the FM modulator of the present invention includes two all-pass type phase shift circuits including a differential amplifier and a CR circuit, and cascade-connects these two phase shift circuits to output the output of the phase shift circuit at a subsequent stage. Is fed back to the input side of the phase shift circuit in the preceding stage, and F ⁇ ⁇ ⁇ ⁇ is used as a resistor in the CR circuit included in one of the two phase shift circuits, and the gate of the F ⁇ ⁇ is used.
  • an FM-modulated signal is output from one of the two phase shift circuits.
  • FM modulation can be directly performed by changing a resistance or an element constant of a capacity according to a signal input from the outside, and the circuit configuration of the entire FM modulation device can be simplified. Also, since an all-pass type circuit is used, a stable output amplitude can always be obtained regardless of the output frequency.
  • FIG. 1 is a diagram showing a configuration of an FM modulator according to a first embodiment
  • FIG. 2 is a diagram showing another configuration of the FM modulator
  • FIG. 3 is a circuit diagram showing the configuration of an oscillator in which the FET included in the FM modulator shown in FIG. 1 and its peripheral circuits are replaced by resistors having fixed resistance values,
  • Fig. 4 is a vector diagram related to the human output voltage etc. of the preceding phase shift circuit shown in Fig. 3
  • Fig. 5 is a vector related to the human output voltage etc. of the subsequent phase shift circuit shown in Fig. 3.
  • Fig. 6 is a circuit diagram showing the configuration of the phase shift circuit including the FET.
  • FIG. 7 is a circuit diagram showing a configuration of a phase shift circuit including an LR circuit
  • FIG. 8 is a vector diagram relating to the input / output voltage of the phase shift circuit shown in FIG. 7,
  • FIG. 9 is a circuit diagram showing another configuration of the phase shift circuit including the LR circuit,
  • FIG. 10 is a vector diagram relating to input / output voltages and the like of the phase shift circuit shown in FIG. 9,
  • FIG. 11 is a circuit diagram showing a configuration of a phase shift circuit including a FET as a part of the LR circuit
  • FIG. 12 is a circuit diagram showing another configuration of the phase shift circuit including the FET in a part of the LR circuit.
  • FIG. 13 is a configuration diagram of an oscillator having a voltage dividing circuit in the phase shift circuit.
  • FIG. 14 is a circuit diagram showing another configuration of the oscillator,
  • FIG. 15 is a circuit diagram showing a configuration of a phase shift circuit that can be replaced with the preceding phase shift circuit shown in FIG. 14,
  • FIG. 16 is a circuit diagram showing a configuration of a phase shift circuit that can be replaced with the subsequent phase shift circuit shown in FIG. 14,
  • FIG. 17 is a circuit diagram showing a detailed configuration of an FM modulator according to a fourth embodiment.
  • FIG. 18 is a circuit diagram showing a configuration of an oscillator including a phase inversion circuit.
  • FIG. 19 is a circuit diagram showing another configuration of an oscillator including a phase inversion circuit
  • FIG. 20 is a circuit diagram showing a detailed configuration of an FM modulator according to a seventh embodiment
  • FIG. 21 is a circuit diagram showing the configuration of an oscillator in which the FET and its peripheral circuits included in the FM modulator shown in FIG.
  • FIG. 22 is a vector diagram relating to input / output voltages and the like of the preceding phase shift circuit shown in FIG. 21;
  • FIG. 23 is a vector diagram relating to the input / output voltage of the subsequent phase shift circuit shown in FIG. 21;
  • FIG. 24 is a circuit diagram showing a configuration of a phase shift circuit including FET,
  • FIG. 25 is a circuit diagram showing a configuration of a phase shift circuit that can be replaced with the preceding phase shift circuit shown in FIG. 21;
  • Fig. 26 is a vector diagram of the input / output voltage of the phase shift circuit shown in Fig. 25, and Fig. 27 is a phase shift circuit that can be replaced with the subsequent phase shift circuit shown in Fig. 21 Circuit diagram showing the configuration of
  • FIG. 28 is a vector diagram showing input / output voltages of the phase shift circuit shown in FIG. 27,
  • FIG. 29 is a circuit diagram showing a configuration of a phase shift circuit including an FET in a part of the LR circuit,
  • FIG. 30 is a circuit diagram showing a configuration of a phase shift circuit including a variable capacitance element,
  • FIG. 31 is a circuit diagram showing a configuration of an oscillator including a phase inversion circuit
  • FIG. 32 is a circuit diagram showing another configuration of an oscillator including a phase inversion circuit
  • FIG. 33 is a circuit diagram showing the configuration of the FM modulator according to the tenth embodiment.
  • FIG. 34 is a diagram showing the FET and its peripheral circuits included in the FM modulator shown in FIG. A circuit diagram showing a configuration of an oscillator in which the value is replaced by a fixed resistor,
  • FIG. 35 is a vector diagram relating to the input / output voltage of the former phase shift circuit shown in FIG. 34,
  • FIG. 36 is a vector diagram relating to the input and output voltages of the subsequent phase shift circuit shown in FIG. 34,
  • FIG. 37 is a circuit diagram showing the configuration of a phase shift circuit including FET,
  • FIG. 38 is a circuit diagram showing a configuration of a phase shift circuit including an LR circuit
  • Fig. 39 is a circuit diagram showing another configuration of the phase shift circuit including the LR circuit.
  • FIG. 40 is a circuit diagram showing the configuration of an oscillator including a phase inversion circuit.
  • FIG. 41 is a circuit diagram showing another configuration of the generator including the phase inversion circuit
  • FIG. 42 is a circuit diagram showing a portion necessary for the operation of the phase shift circuit in the configuration of the operational amplifier.
  • FIG. 1 is a circuit diagram showing a configuration of an FM modulator according to a first embodiment to which the present invention is applied.
  • the FM modulator 1 shown in the figure has a total of 360 at a predetermined frequency.
  • the two phase shifters 1 0 C and 130 C, and the feedback resistor 7 that feeds back the output of the subsequent phase shift circuit 130 C to the input side of the previous phase shift circuit 10 C The feedback resistor 70 has a finite resistance value from 0 ⁇ . These two phase shift circuits 10 C and 130 C and the feedback resistor 70 constitute an oscillator.
  • the FM modulator 1 has an external input terminal 90, and FM-modulates a signal input from the external input terminal 90 and outputs the signal.
  • an amplifier 2 and an antenna 3 are connected after the FM modulator 1, and the output of the FM modulator 1 is amplified by the amplifier 2 and transmitted from the antenna 3 to the air.
  • the signal may be transmitted to the transmission path 400 via the transmitting driver 4 as shown in FIG.
  • FIG. 3 shows the configuration of the oscillator 5 when the FET 35 and its peripheral circuit included in the FM modulator 1 shown in FIG. 1 are replaced with a resistor 36 having a fixed resistance value. It is a circuit diagram.
  • the oscillator 5 shown in the figure is composed of two phase shift circuits 10 C and 30 C that perform a total of 360 ° phase shift at a predetermined frequency, and the output of a subsequent phase shift circuit 30 C. And a feedback resistor 70 for feeding back to the input side of the phase shift circuit 10 C in the preceding stage.
  • the phase shift circuit 10 C at the preceding stage that constitutes the oscillator 5 shown in FIG. 3 is a type of differential amplifier.
  • An operational amplifier (operational amplifier) 12 a resistor 16 that shifts the phase of the signal input to the phase shift circuit 10 C by a predetermined amount, and inputs the resulting signal to the non-inverting input terminal of the operational amplifier 12 and a capacitor 1. 4 and a resistor 18 inserted between the human input end of this phase shift circuit 10 C and the inverted human input terminal of the operational amplifier 12, and a resistor 18 inserted between the output end of the operational amplifier 12 and the inverted input terminal And a resistor 20.
  • the input voltage E1 is obtained by adding the voltage VR1 across the resistor 18 in a vector as shown in FIG.
  • the output voltage Eo is obtained by vectorially subtracting the voltage VR1 of the resistor 20 from i
  • the relationship between the magnitude and phase of the input / output voltage is expressed by the manpower voltage Ei and the output voltage Eo as hypotenuse.
  • the amplitude of the output signal is the same as the amplitude of the input signal regardless of the frequency, and the phase shift ⁇ 0 is shown in Fig. 4. It can be seen that it is represented by 1.
  • the phase shift circuit 30 C of the subsequent stage constituting the oscillator 5 shown in FIG. 3 is provided with an operational amplifier 32 which is a kind of a differential amplifier and a phase of a signal manually input to the phase shift circuit 30 C.
  • An operational amplifier 32 which is a kind of a differential amplifier and a phase of a signal manually input to the phase shift circuit 30 C.
  • phase shift circuit 30 C is the same as that of the previous stage phase shift circuit 10 C, and the connection of the CR circuit composed of the capacitor 34 and the resistor 36 is performed by connecting the phase shift circuit 10 C of the previous stage. From resistor 1 6 and capacitor 1 4 in Is different from the connection of the CR circuit.
  • the output voltage Eo can be expressed as an oblique side and can be expressed as an isosceles triangle with the base of twice the voltage VC2.
  • the amplitude of the output signal is the same as the amplitude of the input signal regardless of the frequency, and the phase shift amount It can be seen that it is represented by 02 shown in FIG.
  • phase of each of the two phase shift circuits 10 C and 30 C is shifted by a certain amount, and the phase is shifted by the entire two phase shift circuits 10 C and 30 C at a predetermined frequency.
  • a signal with a total shift amount of 360 ° is output.
  • the output of the subsequent phase shift circuit 30 C is fed back to the input side of the phase shift circuit 10 C via the feedback resistor 70, and by setting the loop gain of the feedback loop to 1 or more, However, sinusoidal oscillation is performed at such a frequency that the total phase shift amount becomes 360 ° when the circuit makes one round.
  • the resistors 18 and 20 have the same resistance and the resistors 38 and 40 have the same resistance, the gains of the phase shift circuits 10 C and 30 C become 1, In addition, there is a loss in the return loop, so the loop gain is smaller than 1. Therefore, in order to increase the loop gain to 1 or more, the resistance of the resistor 20 must be higher than that of the resistor 18, or the resistance of the resistor 40 must be higher than that of the resistor 38.
  • the FM modulator 1 shown in FIG. 1 is configured such that a resistance value is changed according to the voltage level of an externally input AC signal through a later-stage phase shift [ill path 30 C] included in the oscillator 5 described above.
  • An FM modulator 1 having a configuration in which the phase shifter circuit 130 C including the changing FET 35 is replaced, and having such a configuration will be described.
  • FIG. 6 is a circuit diagram showing a configuration of a phase shift circuit including the above-described FET.
  • FIG. 6A shows a configuration of a subsequent phase shift circuit 130 C included in the FM modulator 1. ing.
  • This phase shift circuit 130 C is a phase shift circuit 30 C included in the oscillator 5 shown in FIG.
  • a CR circuit composed of a capacitor 34 and a resistor 36 is replaced with a capacitor 34
  • a CR circuit consisting of an FET 35 that uses ffl as a resistor applying a predetermined bias to this FET 35 and a resistor 42 that applies a predetermined bias to the gate of the FET 35 from the outside It has a DC current blocking capacitor 44 provided to apply only the AC component of the input signal.
  • each of the two phase shift circuits 10C and 130C constituting the FM modulator 1 is an all-pass circuit, and the amplitude is almost constant even when the frequency of the FM-modulated carrier is changed. This eliminates the need for another configuration to prevent amplitude fluctuations.
  • phase shift circuit 10 C of the preceding stage constituting the oscillator 5 shown in FIG. 3 is replaced with the phase shift circuit 1 10 C shown in FIG. 6B (instead of the resistor 16 in the phase shift circuit 10 C, FET 15, a resistor 22 for bias application and a capacitor 24 for blocking DC current) may be used.
  • both of the two phase shift circuits include a CR circuit, but at least one of the phase shift circuits can be replaced with a phase shift circuit including an LR circuit.
  • FIG. 7 is a circuit diagram showing a configuration of a phase shift circuit 10L that can be replaced with the preceding phase shift circuit 10C included in the oscillator 5 shown in FIG.
  • the phase shift circuit 10 L shown in Fig. 7 is a 1 ° C phase shift circuit shown in Fig. 3, which is a CR circuit consisting of a resistor 16 and a capacitor 14, and an LR circuit consisting of an inductor 17 and a resistor 16.
  • the configuration has been replaced with Considering the relationship between the magnitude and phase of the input / output voltage with the voltage across the inductor 17 as VL1 and the voltage across the resistor 16 as VR1, as shown in Fig. 8, the input voltage Ei and the output voltage Eo And the amplitude of the output signal i ⁇ is the same as the amplitude of the input signal regardless of the frequency. It can be seen that the amount of phase shift is represented by 03 shown in FIG.
  • phase shift circuit 10L is equivalent to the phase shift circuit 10C, and the phase shift circuit 10C can be replaced with the phase shift circuit 10L. Therefore, in the oscillator 5 shown in FIG. 3, the preceding phase shift circuit 10C is replaced with the phase shift circuit 10L shown in FIG. 7, and the latter phase shift circuit 30C is replaced with the phase shift circuit 30C shown in FIG.
  • phase shift circuit 130 C shown in (1) each of the two phase shift circuits can constitute an FM modulator including an LR circuit or a CR circuit.
  • FIG. 9 is a circuit diagram showing a configuration of a phase shift circuit 30L that can be replaced with a subsequent phase shift circuit 30C included in the oscillator 5 shown in FIG.
  • the phase shift circuit 30L shown in Fig. 9 is different from the phase shift circuit 30C shown in Fig. 3 in that the CR circuit consisting of the capacitor 34 and the resistor 36 is replaced by an LR circuit consisting of the resistor 36 and the inductor 37.
  • Configuration Considering the relationship between the magnitude and phase of the input / output voltage with the voltage across the resistor 36 as VR2 and the voltage across the inductor 37 as VL2, as shown in Fig.
  • the input voltage Ei and output voltage Eo are The output signal amplitude is the same as the input signal amplitude regardless of the frequency, and the amount of phase shift is shown in Fig. 10. It can be seen that By the way, assuming that the time constant of the CR circuit in the phase shift circuit 30C shown in FIG. 3 and the time constant of the LR circuit in the phase shift circuit 30L shown in FIG. The transfer functions of the paths 30 C and 30 L are both 1 (1 ⁇ Ts) / (1 + Ts). As described above, the phase shift circuit 30L is equivalent to the phase shift circuit 30C, and the phase shift circuit 30C can be replaced with the phase shift circuit 30L. Therefore, in the oscillator 5 shown in FIG.
  • each of the two phase shift circuits can constitute an FM modulator including an LR circuit or a CR circuit. Also, in the various FM modulators described above, an external signal is input to the phase shift circuit including the CR circuit, but the external signal may be manually input to the phase shift circuit including the LR circuit. Good.
  • FIG. 11 is a circuit diagram showing a configuration of a phase shift circuit including a FET in a part of the LR circuit.
  • Fig. 11 (A) shows a phase shifter using a FET 15, a resistor 22 for bias application, and a capacitor 24 for blocking DC current, instead of the resistor 16 in the phase shift circuit 10L shown in Fig. 7.
  • the configuration of M road 110L is shown.
  • the FM modulator can be configured by replacing the phase shift circuit 10 (:) in the preceding stage with the phase shift circuit 110L shown in Fig. 11 (A).
  • the preceding phase shift circuit 10 ⁇ is replaced with the phase shift circuit 110L shown in FIG. 11 (A), and the latter phase shift circuit 30C is shown in FIG.
  • the FM modulator can be configured by replacing the phase shift circuit 30 shown.
  • Fig. 11 (B) shows a phase shifter using a FET 35, a resistor 42 for applying a bias, and a capacitor 44 for blocking DC current, instead of the resistor 36 in the phase shift circuit 30L shown in Fig. 9.
  • 19 shows a configuration of a circuit 130L.
  • an FM modulator can be configured by replacing the subsequent phase shift circuit 30C with the phase shift circuit 130L shown in FIG. 11 (B).
  • the subsequent phase shift circuit 30 C is replaced with the phase shift circuit 130 shown in FIG. 11B, and the preceding phase shift circuit 10 C is replaced with the seventh phase. It is possible to construct an FM modulator by substituting the phase shift circuit 10 shown in FIG.
  • the resistance value of the resistor formed by FET is changed by an externally input signal, but the capacitance of the capacitor constituting the CR circuit is externally input. It may be changed by a different signal.
  • FIG. 12 is a circuit diagram for reducing the configuration of a phase shift circuit including a variable capacitance element in a CR circuit.
  • Fig. 12 (A) shows the FET 35 in the phase shifter 130C shown in Fig. 6 (A) as the fixed resistor 36, and the capacitor 34 as the variable capacitance diode 34-1 and DC current blocking.
  • FIG. 34-2 shows the configuration of the phase shifter 1 30 C ′ in which 11 is replaced.
  • a bias circuit is formed by the two resistors 42 and 43, and only the AC component of the input signal passes through the capacitor 44. And this AC component is superimposed on a predetermined bias voltage to become a reverse bias voltage applied to the oj variable capacitance diode 34-1.
  • phase shift circuit 130 C ′ is shown in FIG. 6 (A) because the capacitance of the J variable capacitance diode 34-1 changes slightly according to the signal input from the outside.
  • An FM modulation device can be configured by using the phase shift circuit 130C instead of the phase shift circuit 130C.
  • Fig. 12 (B) shows the FET 15 in the phase shift circuit 110C shown in Fig. 6 (B) as the fixed resistor 16 and the capacitor 14 as the variable capacitance diode 1.
  • the structure of the phase shifter 110 C ′ replaced with each other is shown in Fig. 4-11 and the capacity for DC current blocking.
  • a bias circuit is formed by the two resistors 22 and 23, and only the AC component of the input signal is separated by passing through the capacitor 24, and this AC component is separated by a predetermined bias.
  • the reverse bias voltage is superimposed on the voltage and applied to the variable capacitance diode 14 11.
  • phase shift circuit 110C is replaced with the phase shift circuit shown in FIG. 6 (B). By using it in place of 110 C, it is possible to configure an FM modulator.
  • each phase shift circuit shown in Fig. 3 the output of the operational amplifier is directly fed back to the input side of the operational amplifier via the feedback resistor 70, but the voltage divider is connected to the output terminal of each operational amplifier.
  • the output may be ii on the human side of the operational amplifier.
  • FIG. 13 is a circuit diagram showing a detailed configuration of an oscillator provided with a voltage dividing circuit in the Park I circuit.
  • a voltage dividing circuit composed of resistors 28 and 29 is connected to the output terminal of the operational amplifier 12 in the phase shift circuit 210C.
  • the output terminal is connected to the inverting human terminal of the operational amplifier 12 via the resistor 20.
  • a voltage dividing circuit composed of resistors 48 and 49 is connected to the output terminal of the operational amplifier 32 in the phase shift circuit 230 C.
  • the voltage dividing output terminal is connected to the operational amplifier via the resistor 40. 3 Connected to 2 inverted human power terminals.
  • the resistance in the CR circuit of either one of the two phase shift circuits 210C and 230C shown in Fig. 13 is configured by using the FET and the bias application resistance.
  • an FM modulator can be configured in the same manner as in FIG.
  • FIG. 13 shows an example in which a voltage dividing circuit is connected to the output terminals of the operational amplifiers 12 and 32 in the phase shift circuits 10 C and 30 C shown in FIG.
  • Connect a divider / operator circuit to the output terminals of the operational amplifiers 12 and 32 in the phase shift circuits 10 L and 30 L shown in the figures and Fig. 9, and connect the voltage divider output terminals to the operational amplifiers 12 and 3 2 respectively.
  • the same stable oscillating operation as that of the oscillator 5A shown in FIG. 13 is performed.
  • FIG. 14 is a circuit diagram showing another configuration of the oscillator.
  • the oscillator 5B shown in the figure is configured to include two phase shift circuits 410C and 430C that perform a total of 360 ° phase shift at a predetermined frequency.
  • the frequency of the input AC signal changes by setting the resistance values of the resistors 18 and 20 in the preceding phase shift circuit 10C to the same value. It suppresses the amplitude change when it is turned on.
  • the phase shift circuit 410C in the preceding stage included in the oscillator 5B shown in FIG. The phase shift circuit 4 1 0
  • the gain of C is set to a value greater than 1.
  • phase shift circuit 430 C By setting the resistance value of the resistor 40 ′ larger than the resistance value of the resistor 38 ′, the gain of the phase shift circuit 430 C is increased. Set to a value greater than 1.
  • gain fluctuation may occur depending on the frequency of the input signal.
  • the gain at this time becomes 1 because the phase shift circuit 410 C becomes a voltage follower circuit.
  • the phase shift circuit 410C becomes an inverting amplifier, so the gain at this time is 1 m (m is the resistance ratio between the resistance 20 'and the resistance 18').
  • Such amplitude fluctuations can be suppressed by connecting a resistor 19 to the inverting input terminal of the operational amplifier 12 and matching the gains when the input frequency is low and high.
  • the input signal is set by setting the resistance value of the resistor 19 to mr / (m-1).
  • Each gain of the phase shift circuit 410C when the frequency of the signal is 0 and infinity can be matched.
  • the phase shift circuit 43OC by connecting a resistor 39 having a predetermined resistance value to the inverting input terminal of the operational amplifier 32, the amplitude fluctuation of the output i can be suppressed.
  • one ends of the resistors 19 and 39 may be connected to a fixed potential other than the ground level.
  • an FM modulator can be configured in the same manner as in FIG. '
  • the oscillator 5B shown in Fig. 14 has a cascade connection of phase shift circuits 411C and 430C including a CR circuit, but the CR circuit can be replaced with an LR circuit. It is.
  • the phase shift circuit 4 10 shown in FIG. This is equivalent to 10 C, and the phase shift circuit 410 C can be replaced with a phase shift circuit 410 L.
  • the phase shift circuit 430 L shown in FIG. 16 is equivalent to the subsequent phase shift circuit 430 C shown in FIG. Can be replaced by 4300L.
  • an FM modulator can be configured in the same manner as in FIG.
  • the phase shift amount of the two phase shift circuits is set to be 360 ° at a predetermined frequency, but the two phase shift circuits are connected in cascade.
  • the FM modulator may be configured by connecting a non-inverting circuit that does not change the phase to a part of the formed feedback loop.
  • FIG. 17 is a circuit diagram showing a detailed configuration of the FM modulator according to the fourth embodiment.
  • the FM modulator 1A shown in the figure is the same as the FM modulator 1 shown in FIG. 1 in that the phase shift circuit 10C and the phase shift circuit 13OC are connected in cascade, and the subsequent phase shifter is used. This is different from the FM modulator 1 shown in FIG. 1 in that a non-inverting circuit 50 is connected to the output side of the circuit 130 C.
  • the non-inverting circuit 50 includes an operational amplifier 52 and resistors 54 and 56, and has a predetermined gain according to a resistance ratio of the two resistors 54 and 56. Therefore, the loss at the time of forming the closed loop can be compensated by this gain, and the loop gain of the feedback loop can be easily set to 1 or more. Further, the non-inverting circuit 50 can have a function as a power amplification stage.
  • FIG. 17 as an example, the configuration in which the non-inverting circuit 50 is connected to the FM modulator 1 shown in FIG. 1 is described, but the above-described various phase shift circuits are cascaded in an arbitrary order.
  • the non-inverting circuit 50 shown in FIG. 17 may be connected to various FM modulators configured as described above.
  • the oscillation operation was performed at a frequency where the total amount of phase shift by the two phase shift circuits was 360 °, but the phase inversion circuit must be connected in a closed loop. Accordingly, the oscillation operation may be performed at a frequency at which the total amount of phase shift by the two phase shift circuits is 180 °.
  • FIG. 18 is a circuit diagram of an oscillator configured by cascade-connecting two phase shift circuits and a phase inversion circuit.
  • the oscillator 5C shown in the figure has a two-stage cascade connection of the preceding stage phase shift circuit 10C in the oscillator 5 shown in FIG. 3, and an operational amplifier 82 and resistors 84, 86 at the subsequent stage.
  • the phase inversion circuit 80 is connected, and the output of the phase inversion circuit 80 is fed back to the human side of the preceding phase shift circuit 10 C via the feedback resistor 70.
  • the phase shift amount when making a round of the closed loop is 3 60 °, and a predetermined oscillation operation is performed by setting the loop gain of the feedback loop at this time to 1 or more.
  • the FM modulator used for the FM modulation signal can be configured.
  • one of the two phase shift circuits 10 C included in the damper 5 C is replaced with the phase shift circuit 110 C shown in FIG. 6 (B), and the other is replaced with the phase shift circuit 110 C shown in FIG.
  • the FM modulator may be configured by replacing the phase shift circuit 10L shown in the figure.
  • the FM modulator may be configured by replacing the capacity in the CR circuit included in one of the two phase shift circuits 10 C with a variable capacitance diode and a resistor for bias application.
  • the oscillator 5 C shown in FIG. 18 shows an example in which the phase shift circuit 10 C is cascaded, but the oscillator is constructed by cascading the subsequent phase shift circuit 30 C shown in FIG. You may.
  • FIG. 19 is a circuit diagram showing another configuration of the oscillator including the phase inversion circuit.
  • the oscillator 5D shown in the figure has a cascade connection of two stages of the phase shift circuit 30C at the subsequent stage in the oscillator 5 shown in FIG. 3, and a phase inversion circuit 80 is connected to the subsequent stage.
  • the output of the circuit 80 is fed back to the input side of the preceding phase shift circuit 30 C via the feedback resistor 70. ing.
  • the phase inverting circuit 80 Since the signal is inverted by the phase inverting circuit 80, when the total phase shift amount of the two phase shift circuits 30C is 180 °, the phase shift amount when making a round of the closed loop becomes 3 60 °, and a predetermined oscillation operation is performed by setting the loop gain of the feedback loop at this time to 1 or more.
  • an FM modulator by replacing one of the two phase shift circuits 30 C included in the oscillator 5 D with the phase shift circuit 130 C shown in FIG. 6 (A). it can.
  • one of the two phase shift circuits 30C included in the oscillator 5D is replaced with the phase shift circuit 130C shown in FIG. 6 (A), and the other is shifted as shown in FIG.
  • the phase modulation circuit may be replaced with 30 L to form an FM modulator.
  • FIG. 20 is a circuit diagram showing a detailed configuration of the FM modulator according to the seventh embodiment.
  • the FM modulator 1B shown in the figure includes two phase shift circuits 61 0C and 73 0 that perform a total of 360 ° phase shift at a predetermined frequency, and a phase shift circuit 73 0 at the subsequent stage.
  • a non-inverting circuit 650 that amplifies and outputs the output signal of C at a predetermined amplification level without changing the phase, and an output of the non-inverting circuit 65 0 It is configured to include a feedback resistor 670 for feeding back.
  • This feedback resistor 670 has a finite resistance value from 0 ⁇ .
  • the feedback resistor 670 and the capacitor 672 connected to the column are for blocking DC current, and the impedance is extremely small at the operating frequency, that is, it has a large capacitance. I have.
  • the FM modulator 1B has an external input terminal 90, and outputs a signal input from the external input terminal 90 as an FM modulated signal.
  • an amplifier 2 and an antenna 3 are connected to the subsequent stage of the FM modulator 1B, and the output of the FM modulator 1B is amplified by the amplifier 2 and transmitted from the antenna 3 to the air. Then it becomes an FM wireless transmitter.
  • the signal may be transmitted to the transmission path 400 via the transmission driver 4 as shown in FIG.
  • FIG. 21 is a circuit diagram showing a configuration of the oscillator 5E in which the FET 635 included in the FM modulator 1B shown in FIG. 20 and its peripheral circuit are replaced with a resistor 636 having a fixed resistance value. is there.
  • the generator 5E shown in the figure is composed of two phase shift circuits 6 10C and 630C that perform a total of 360 ° phase shift at a predetermined frequency, and the output signals of the subsequent phase shift circuit 630C.
  • a non-inverting circuit 650 that amplifies and outputs a predetermined degree of amplification without changing the phase, a feedback resistor 670 that feeds back the output of the non-inverting circuit 650 to the input side of the two-stage phase shifting circuit 6100 It is composed of
  • the phase shift circuit 610C of the preceding stage constituting the oscillator 5 shown in Fig. 21 is composed of an FET 612 whose gate is connected to the human-powered end of the phase shift circuit 610C, and a FET 612
  • the capacitor 614 and the resistor 616 connected in series with the drain of the FET's, the resistor 618 connected between the drain of FE 612 and the positive power supply, and the FET 612 And a resistor 620 connected between the source and the ground.
  • the resistor 626 in the phase shift circuit 610 C is for applying an appropriate bias voltage to the FET 612.
  • at least one of the F ⁇ 6 12 and the F ⁇ 632 described later may be replaced with a bipolar transistor.
  • the resistance values of the two resistors 620 and 618 connected to the source and drain of F ⁇ 1 6 12 described above are set substantially equal, and the input voltage applied to the gate is Focusing on the AC component, a signal with the same phase is output from the source of FET 612, and a signal whose phase is inverted and whose amplitude is equal to the signal output from the source is output from the drain of F ⁇ 612 It is output as it is.
  • the amplitude of the AC voltage appearing at the source and drain is Ei.
  • a series circuit composed of a capacitor 614 and a resistor 616 is connected between the source and the drain of the FET 612, and the voltage appearing at the source and the drain of the FET 612 is connected.
  • a signal obtained by synthesizing them through the resistor 616 or the capacitor 614 is output from the phase shift circuit 610C.
  • the ti voltage VC1 appearing at both ends of the capacitor 614 and the voltage VR1 appearing at both ends of the resistor 616 are 90 ° out of phase with each other, and the vector combination of these is the FET 6 1 Since the voltage between the source and drain of 2 is equal to 2 Ei, As shown in Fig. 22, the hypotenuse is defined as twice the voltage Ei, and the voltage VC1 across the capacitor 614 and the voltage VR1 across the resistor 616 form a right-angled triangle forming two sides that are orthogonal to each other. .
  • this output voltage Eo starts at the center point of the semicircle shown in FIG. It can be represented by a vector ending at a point on the circumference where VC1 and voltage VR1 intersect.
  • the amplitude of the output signal is constant regardless of the frequency, and the amount of phase shift is shown in Fig. 22. It can be seen that it is represented by 05 shown in Fig.
  • the phase shift circuit 630C of the subsequent stage constituting the oscillator 5E shown in FIG. 21 includes a FET 632 whose gate is connected to the input terminal of the phase shift circuit 630C, and a source and a drain of the FET 632.
  • the resistor 636 and the capacitor 634 connected in series with the resistor 632, the resistor 638 connected between the drain of the FET 632 and the positive power supply, and the resistor 640 connected between the source of the FET 632 and the ground. It is comprised including.
  • the resistor 646 in the phase shift circuit 630 C is for applying an appropriate bias voltage to the FET 632, and the capacitor 648 inserted between the phase shift circuit 630 C and It is for current blocking.
  • This phase shift circuit 630C has the same basic configuration as the phase shift circuit 610C in the preceding stage.
  • the connection of the CR circuit consisting of the resistor 636 and the capacitor 634 is connected to the phase shift circuit 610C in the preceding stage.
  • the difference is that the connection is opposite to the connection of the CR circuit consisting of the capacity 6 14 and the resistor 6 16.
  • the amplitude of the output signal is constant regardless of the frequency, and the amount of phase shift is denoted by 06 in Fig. 23. It can be seen that it is represented. In this way, the phase is shifted by a predetermined amount in each of the two phase shift circuits 610C and 630C, and the whole of the two phase shift circuits 610C and 630C at a predetermined frequency is changed. As a result, a signal having a total phase shift amount of 360 ° is output.
  • the non-inverting circuit 650 shown in FIG. 21 has a resistor 654 between the drain and the positive power supply, and a FET 656 connected between the source and the ground. Appropriate bias voltage to FET 652, transistor 652 whose base is connected to the drain of FET 652, and whose collector is connected to the source via resistor 660 And a resistor 6 62.
  • the capacity 664 provided before the non-inverting circuit 650 shown in FIG. 21 is for blocking DC current that removes a DC component from the output of the subsequent phase shift circuit 630C. Yes, only the AC component is input to the non-reverse circuit 650.
  • the FET 652 When an AC signal is input to the gate, the FET 652 outputs a signal of the opposite phase from the drain. Also, when the signal having the opposite phase is input to the base, the transistor 658 becomes a signal whose phase is further inverted, that is, the signal having the same phase when considering the phase of the signal input to the gate of the FET 652 as a reference. Is output from the collector, and this in-phase signal is output from the non-inverting circuit 650. The output of the non-inverting circuit 650 is taken out from the output terminal 92 as the output of the oscillator 5E, and is fed back to the input side of the preceding phase shift circuit 610C via the feedback resistor 670. I have.
  • the amplification degree of the non-inverting circuit 65 0 described above is determined by the respective resistance values of the above-described resistors 65 4, 65 6, and 66 0.
  • the loop gain of the feedback loop formed by including the two phase shift circuits 61 0 C and 63 0 C and the feedback resistor 67 0 shown in Fig. 1 can be set to 1 or more. Then, a sine wave oscillation is performed at a frequency such that the total phase shift amount is 360 °.
  • FIG. 24 is a circuit diagram showing a configuration of the phase shift circuit including the FET described above.
  • (A) shows the configuration of the subsequent phase shift circuit 730C included in the FM modulator 1B.
  • the phase shift circuit 730C is a phase shift circuit 630C in the subsequent stage included in the oscillator 5E shown in FIG.
  • the resistor 642 for applying a predetermined bias to this FET 635 and the AC component of the signal input externally to the gate of the FET 635 are used. It has a current blocking capacitor 644 provided for application.
  • the channel resistance between the source and the drain of the FET 635 is minutely changed by using the FET 635 as a resistor and inputting a signal from the outside to the gate of the FET 635.
  • the two phase shift circuits 6 10 C and 730 C constituting the FM modulator 1 B are all-pass circuits, and even if the frequency of the FM-modulated carrier is changed, the amplitude is changed. Is almost--, and another configuration for preventing amplitude fluctuation is not required.
  • an external signal is input to the subsequent phase shift circuit 730C, but an external signal is input to the preceding phase shift circuit 6100C.
  • the number may be input. That is, the phase shift circuit 610C of the preceding stage constituting the oscillator 5E shown in FIG. 21 is replaced by the phase shift circuit 710C shown in FIG. 24 (B) (the phase shift circuit 610C).
  • a resistor 622 of FET 6 15 and a bias application ffl of the resistor 622 and a capacitor 624 for blocking DC current may be used.
  • both of the two phase shift circuits include a CR circuit, but at least one of the phase shift circuits is replaced with a phase shift circuit including an LR circuit. You can also.
  • FIG. 25 is a circuit diagram showing a configuration of a phase shift circuit 6100L that can be replaced with the preceding phase shift circuit 6100C included in the oscillator 5E shown in FIG.
  • the phase shift circuit 610 L shown in FIG. 25 is different from the phase shift circuit 61 0 C shown in FIG. 21 in that a CR circuit consisting of a capacitor 614 and a resistor 6 16 is connected to a resistor 6 16 It has a configuration in which it is replaced with an LR circuit consisting of an inductor 6 17. Assuming that the voltage between both ends of the resistor 6 16 is VR1 and the voltage between both ends of the inductor 6 17 is VL1, as shown in FIG.
  • the oblique side is twice the voltage Ei, and the voltage VR1 across the resistor 6 16 and the inductor In the evening, the voltage VL1 at both ends of 617 forms a right triangle forming two sides that are orthogonal to each other.
  • this output voltage Eo starts from the center point of the semicircle shown in FIG. It can be represented by a vector ending at a point on the circumference where voltage VR1 and voltage VL1 intersect.
  • the amplitude of the output signal is constant regardless of the frequency, and the amount of phase shift is shown in Fig. 26. It can be seen that it is represented by 07 shown.
  • phase shift circuit 610L is equivalent to the phase shift circuit 610C, and the phase shift circuit 610C can be replaced with the phase shift circuit 610L. Therefore, in the oscillator 5E shown in FIG. 21, the former-stage phase shift circuit 610C is replaced with the phase-shift circuit 610 L shown in FIG. 25, and the latter-stage phase shift circuit 630C is replaced.
  • phase shift circuit 730C shown in Fig. 24 (A) each of the two phase shift circuits can constitute an FM modulator including an LR circuit or a CR circuit.
  • FIG. 27 is a circuit diagram showing a configuration of a phase shift circuit 630L which can be replaced with a subsequent phase shift circuit 630C included in the oscillator 5E shown in FIG.
  • the phase shift circuit 630 L shown in FIG. 27 is different from the phase shift circuit 630 C shown in FIG. 21 in that a CR circuit comprising a resistor 636 and a capacitor 634 is replaced by an LR comprising an inductor 637 and a resistor 636. It has a configuration replaced with a circuit.
  • V across inductor 637 Assuming that the voltage across L2 and the resistor 636 is VR2, as shown in Fig.
  • phase shift circuit 63 0 C shown in Fig. 21 and the time constant of the LR circuit in the phase shift circuit 63 0 L shown in Fig. 27 are both T.
  • the transfer functions of these phase shift circuits 63 0 C and 63 0 L are both-a (1-T s) / (1 + T s).
  • each of the two phase shift circuits can constitute an FM modulator including an LR circuit or a CR circuit .
  • an external signal is input to the phase shift circuit including the CR circuit, but an external signal may be input to the phase shift circuit including the LR circuit. Good.
  • FIG. 29 is a circuit diagram showing a configuration of a phase shift circuit including an FET in a minus portion of the LR circuit.
  • the 29th (A) is replaced with the FET 615, biasing resistor 622 and DC current blocking instead of the resistor 616 in the phase shift circuit 610L shown in Fig. 25.
  • the figure shows a configuration of a phase shift circuit 7110 L using a capacitor 624 for use. ⁇
  • the FM modulator by replacing the phase shift circuit 6100C in the preceding stage with the phase shift circuit 7 10L shown in Fig. 29 (A). it can.
  • the preceding phase shift circuit 6100C is replaced with the phase shift circuit 7100L shown in FIG. 6 3 0 C
  • An FM modulator can be configured by replacing the phase shift circuit 630 L shown in FIG.
  • a FET 635 instead of the resistor 636 in the phase shift circuit 630L shown in Fig. 27, a FET 635, a resistor 642 for applying a bias, and a capacitor 644 for blocking a DC current are used.
  • the configuration of the phase shift circuit 730L is shown.
  • the subsequent phase shift circuit 630C can be replaced with the phase shift circuit 730L shown in FIG. 29 (B) to constitute an FM modulator.
  • the subsequent phase shift circuit 630C is replaced by the phase shifter 730L shown in FIG.
  • the FM modulator can be constructed by replacing 10 C with the phase shift circuit 6 10 L shown in FIG.
  • the resistance of the resistor formed by FET is changed by a signal input from the outside, but the capacity of the CR circuit is changed by a signal input from the outside. You may make it change.
  • FIG. 30 is a circuit diagram showing a configuration of a phase shift circuit in which a variable capacitance element is included in a CR circuit.
  • Fig. 30 (A) shows the FET 635 in the phase shift circuit 730C shown in Fig. 24 (A) as the fixed resistor 636, and the capacity 634 as the variable capacitance diode 634-1 and
  • the configuration of the phase shift circuit 730 C ' is shown in Fig. 64-2, which is a DC current blocking capacitor.
  • a bias circuit is formed by the two resistors 642 and 643, and only the AC component of the signal to be input is separated by passing through the capacitor 644, and this AC component is superimposed on a predetermined bias voltage.
  • variable capacitance diode 634-1 As a result, a reverse bias voltage is applied to the variable capacitance diode 634-1. Since the capacitance of the variable capacitance M-diode 634-1 changes slightly according to the signal input from the outside, the above-described phase shift circuit 730C 'is connected to the phase shift circuit shown in FIG. 24 (A). By using the circuit instead of the circuit 730C, an FM modulator can be configured.
  • Fig. 30 (B) shows the FET 615 in the phase shift circuit 710 shown in Fig. 24 (B) as the fixed resistor 616, and the capacitor 614 as the variable capacitance diode 6 1 4 1 1 and phase shifter replaced by DC current blocking capacitor 6 14- [o] shows the configuration of the path 7110C '. Also, a bias circuit is formed by the two resistors 6 2 2 and 6 2 3, and only the AC component of the input signal is separated by passing through the capacitor 6 24, and this AC component is The reverse bias voltage is superimposed on the voltage and applied to the variable capacitance diode 6 14-4-1.
  • phase shift circuit 7 110 C is shown in FIG. 24 (B).
  • the FM modulator can be configured.
  • the oscillation operation is performed at a frequency at which the sum of the phase shifts fi by the two phase shift circuits is 360 °, but within the closed loop.
  • the oscillation operation may be performed at a frequency at which the total phase shift amount of the two phase shift circuits is 180 °.
  • FIG. 31 is a circuit diagram of an oscillator configured using two phase shift circuits and a phase inversion circuit.
  • the oscillator 5F shown in the figure is composed of a two-stage cascade connection of the preceding phase-shift circuit 6100C in the oscillator 5E shown in FIG. 21I, and a FET 682 and a resistor 684
  • a phase inverting circuit 680 composed of the phase inverting circuit 686 and the output of the phase inverting circuit 680 is fed back to the input side of the preceding phase shift circuit 610C via the resistor 670.
  • the sum of the phase shifts:: by the two phase shifting circuits 610C is 1800.
  • the phase shift amount when the circuit goes through the closed loop becomes 360 °, and a predetermined oscillation operation is performed by setting the loop gain of the feedback loop at this time to 1 or more.
  • phase shift circuit 710C shown in FIG. 29 (A) or the phase shift circuit 7 shown in FIG. 30 (B) may be used.
  • Use 10 C or other The phase shift circuit 610 L shown in FIG. 25 may be used as the other phase shift circuit (a phase shift circuit to which no external signal is input).
  • FIG. 32 is a circuit diagram of another oscillator configured by cascading two phase shift circuits and a phase inversion circuit.
  • the oscillator 5G shown in the figure has a two-stage cascade connection of the subsequent phase shift circuit 630C in the oscillator 5E shown in FIG. 21 and a phase inversion circuit 680 connected to the subsequent stage. Then, the output of the phase inversion circuit 680 is fed back to the input side of the preceding phase shift circuit 630 C via the resistor 670.
  • the phase inverting circuit 680 Since the signal is inverted by the phase inverting circuit 680, when the total phase shift amount by the two phase shifting circuits 630C is 180 °, the phase shift when the circuit goes through a closed loop ffi becomes 360 °, and a predetermined generating operation is performed by setting the loop gain of the feedback loop at this time to 1 or more.
  • phase shift circuit 730C shown in FIG.
  • An FM modulator that converts signals into FM modulation signals can be configured.
  • the phase shift circuit 730 C instead of the above-described phase shift circuit 730 C, the phase shift circuit 730 L shown in FIG. 29 (B) or the phase shift circuit shown in FIG. 30 (A) 730C may be used, or the phase shift circuit 630L shown in FIG. 27 may be used as the other phase shift circuit (a phase shift circuit to which no external signal is input).
  • FIG. 33 is a circuit diagram showing the detailed configuration of the FM modulator of the tenth embodiment c .
  • the FM modulator 1C shown in FIG. 33 does not change the phase of the input AC signal.
  • the non-inverting circuit 850 functions as a buffer circuit, and includes, for example, an emitter follower circuit, a source follower circuit, and the like.
  • the non-inverting circuit 850 is omitted and the FM modulator is omitted. Make up 1 C Is also good.
  • the FM modulator 1C shown in FIG. 33 has an external input terminal 90.
  • the signal input from the external input terminal 90 is FM-modulated and output.
  • the output of the FM modulator 1 is amplified by the amplifier 2 and transmitted from the antenna 3 to the air. Becomes an FM wireless transmitter.
  • the signal may be transmitted to the transmission line 400 via the transmitting driver 4 as shown in FIG.
  • Fig. 34 shows the configuration of the oscillator when the FET 835 and its peripheral circuit included in the FM modulator 1C shown in Fig. 33 are replaced with a fixed resistor 836.
  • the preceding phase shift circuit 810C shown in the figure is a differential amplifier 812 that amplifies the differential voltage of the two inputs with a predetermined amplification and outputs the amplified signal, and a phase difference of the input AC signal by a predetermined amount.
  • the capacitance and the resistance input to the non-inverting human input terminal of the differential amplifier 812 are shifted to about 1/2 of the voltage level without changing the phase of the input AC signal.
  • the resistors 818 and 820 to be input to the inverting input terminal of the differential amplifier 812.
  • FIG. 35 is a vector ⁇ showing the relationship between the human output voltage of the phase shift circuit 8100 C shown in FIG. 34 and the voltage appearing in the capacity and the like.
  • the voltage VR1 appearing at both ends of the resistor 816 and the voltage VC1 appearing at both ends of the capacitor 814 are 90 ° out of phase with each other.
  • the phase shift circuit is equivalent to a human input voltage Ei of 8100C. Therefore, when the amplitude of the input voltage E i is constant and only the frequency changes, the voltage VR1 across the resistor 8 16 and the voltage across the capacitor 8 14 along the circumference of the semicircle shown in FIG. The voltage VC1 changes.
  • the voltage H applied to the non-inverting input terminal of the differential amplifier 812 (the voltage VC1 across the capacitor 814) is applied to the voltage applied to the inverting human terminal (the voltage across the resistor 8200).
  • the vector obtained by subtracting E i / 2) is the difference voltage E o '.
  • This difference voltage E o ' is expressed as a vector with the center point as the starting point and the end point at one point on the circumference where voltage VC1 and voltage VR1 intersect in the semicircle shown in Fig. 35. And its size is equal to the radius of the semicircle E i / 2.
  • the output voltage Eo of the differential amplifier 812 is obtained by amplifying the differential voltage Eo 'with a predetermined amplification factor. Therefore, the above-described phase shift circuit 8100C operates as an all-pass circuit because the output voltage E o is constant irrespective of the frequency of the input voltage E i. Further, as is apparent from FIG. 35, since the voltage VC1 and the voltage VR1 intersect at right angles on the circumference, the phase difference between the input voltage Ei and the voltage VC1 varies from a frequency ⁇ of 0 to ⁇ . Then, it changes from 0 ° to 90 ° in the clockwise direction (phase lag direction) based on the human-power voltage E i. Then, the phase shift amount 09 of the entire phase shift circuit 8110C changes from 0 ° to 180 ° according to the frequency.
  • the subsequent phase shift circuit 8330C shown in FIG. 34 includes a differential amplifier 832 that amplifies the differential voltage of the two inputs at a predetermined amplification degree and outputs the amplified signal, and a differential amplifier 832 of the input AC signal. After shifting the phase by a predetermined amount, the voltage level of the capacitor 834 and the resistor 836 input to the non-inverting input terminal of the differential amplifier 832, and the voltage level of the input AC signal are changed without changing the phase. It is configured to include resistors 838 and 840 which divide the voltage by 1/2 and input to the inverting input terminal of the differential amplifier 812.
  • FIG. 36 is a vector diagram showing a relationship between the human output voltage of the phase shift circuit 830 C shown in FIG. 34 and the overpressure appearing in the capacity and the like.
  • the voltage VC2 appearing at both ends of the capacitor 834 and the voltage VR2 appearing at both ends of the resistor 836 are 90 ° out of phase with each other, and are vector-wise added. Becomes the input voltage E i. Therefore, when the amplitude of the input signal is constant and only the frequency changes, the voltage V C2 across the capacitor 834 and the voltage across the resistor 836 along the circumference of the semicircle shown in Fig. 36 The voltage VR2 changes.
  • the voltage applied to the non-inverting input terminal of the differential amplifier 832 (the voltage VR2 across the resistor 836) and the voltage applied to the inverting input terminal (the voltage E i / 2 ) Is the difference voltage E o '.
  • the difference voltage E o ′ is calculated from the center point of the graduation circle shown in FIG. It can be represented by a vector ending at a point on the circumference where C2 intersects, and its size is equal to the radius Ei / 2 of the semicircle.
  • the output voltage Eo of the differential amplifier 832 is obtained by amplifying the differential voltage Eo ′ with a predetermined amplification factor. Therefore, the above-described phase shift circuit 830C operates as an all-pass circuit in which the output voltage Eo is constant regardless of the frequency of the input signal.
  • the phase difference between the input voltage Ei and the voltage VR2 increases as the frequency ⁇ changes from 0 to ⁇ . 1 80 ° to 270.
  • the phase shift amount 010 of the entire phase shift circuit 830C changes from 180 ° to 360 ° according to the frequency.
  • the phase of each of the two phase shift circuits 810C and 830C is shifted by a predetermined amount, and the phase shift circuit 810C and 830C as a whole is shifted at a predetermined frequency.
  • a signal with a total of 360 ° is output.
  • the FM modulator 1C shown in FIG. 33 has a phase shifter 830C included in the oscillator 5H shown in FIG. 34 which is connected to a resistor in accordance with the voltage level of an externally input AC signal. It has a configuration in which the phase shift circuit 930C including the FET 835 whose value changes is replaced with a phase shift circuit 930C. Next, an FM modulator 1C having such a configuration will be described.
  • FIG. 37 is a circuit diagram showing a configuration of a phase shift circuit including the above-described FET.
  • FIG. 37A shows a configuration of a subsequent phase shift circuit 930C included in the FM modulator 1C. I have.
  • This phase shift circuit 930C uses a CR circuit composed of a resistor 836 and a capacitor 834 as a resistor between a source and a drain in the subsequent phase shift circuit 830C included in the oscillator 5H shown in FIG.
  • the resistor 842 for applying a predetermined bias to the FET 835 and the AC component of the signal input from the outside to the FET 835 gate are applied. To prevent DC current from being provided.
  • the channel resistance between the source and the drain of the FET 835 slightly changes.
  • FET 835 whose resistance value changes according to the external input, it is possible to easily obtain an FM-modulated signal. Therefore, the circuit configuration itself of the FM modulator 1C can be simplified.
  • the two phase-shift circuits 8100C and 930C that make up the FM modulator 1C are all-pass circuits, and even if the frequency of the FM-modulated carrier is changed, Is almost equal to one, and an additional circuit for preventing amplitude fluctuation is not required.
  • an external signal is input to the subsequent phase shift circuit 930C, but an external signal is input to the preceding phase shift circuit 8100C. May be input. That is, the phase shift circuit 8100C in the preceding stage shown in FIG. 33 is replaced with the phase shift circuit 910C shown in FIG. 37 (B) (in place of the resistor 816 in the phase shift circuit 8100C). , FET 815, resistor 822 for applying bias and capacitor 824 for blocking DC current).
  • both of the two phase shift circuits include a CR circuit, but at least the-phase shift circuit can be replaced with a phase shift circuit including an LR circuit. .
  • FIG. 38 is a circuit diagram showing a configuration of a phase shift circuit 8110L which can be replaced with the preceding phase shift circuit 8100C included in the oscillator 5H shown in FIG.
  • the phase shift circuit 8 10 L shown in FIG. 38 is different from the phase shift circuit 8 10 C shown in FIG. 34 in that a CR circuit consisting of a capacitor 814 and a resistor 8 16 is connected to the resistor 8 16 C. It has a configuration in which it is replaced with an LR circuit consisting of
  • phase shift circuits of 8 10 C and 8 10 L are both a (1 — T s) / (1 + T s: where s 2, where a is each phase shift circuit Is the gain.
  • phase shift circuit 8100L is equivalent to the phase shift circuit 8110C, and the phase shift circuit 8110C can be replaced with the phase shift circuit 8110L. Therefore, the 34th In the oscillator 5H shown in the figure, the former phase shift circuit 8100C is replaced with the phase shift circuit 810L shown in FIG. 38, and the latter phase shift circuit 830C is replaced in FIG.
  • each of the two phase shifters can constitute an FM modulator including an LR circuit or a CR circuit.
  • FIG. 39 is a circuit diagram showing a configuration of a phase shift circuit 830L which can be replaced with a subsequent phase shift circuit 830C included in the oscillator 5H shown in FIG.
  • the phase shift circuit 830L shown in Fig. 39 is different from the phase shift circuit 830C shown in Fig. 34 in that a CR circuit consisting of a resistor 835 and a capacitor 834 is hidden in an LRfyl path consisting of an inductor 837 and a resistor 836. It has a changed configuration.
  • the phase shift circuit 830L is equivalent to the phase shift circuit 830C, and the phase shift circuit 830C can be replaced with the phase shift circuit 830L. Therefore, in the oscillator 5H shown in FIG. 34, the subsequent phase shift circuit 830C is replaced with the phase shift circuit 830L shown in FIG.
  • an FM modulator can be configured.
  • the capacity in the CR circuit included in the preceding phase shift circuit 8100C may be configured using a variable capacitance diode and a bias application resistor.
  • the oscillation operation is performed at a frequency at which the sum of the phase shift amounts by the two phase shift circuits becomes 360 °.
  • the oscillation operation may be performed at a frequency at which the total phase shift amount of the two phase shift circuits is 180 °.
  • FIG. 40 is a circuit diagram of an oscillator configured using two phase shift circuits and a phase inversion circuit.
  • the oscillator 5J shown in the figure is connected to the phase shift circuit 8100C in the oscillator 5J shown in FIG.
  • An inverting circuit is connected, and the output of the subsequent phase shift circuit 830C is fed back to the input side of the phase inverting circuit 880 via a feedback resistor 870.
  • the phase inverting circuit 880 inverts the phase of an input AC signal, and is realized by, for example, an emitter grounding circuit, a source grounding circuit, or a circuit combining an operational amplifier and a resistor.
  • phase shift when the circuit goes through a closed loop is completed. 3600.
  • a predetermined oscillation operation is performed by setting the loop gain of the feedback loop at this time to 1 or less.
  • phase inverting circuit 880 since the phase of the signal is inverted by the phase inverting circuit 880, when the total phase shift amount of the two phase shifting circuits 810C becomes 180 °, when the circuit goes through a closed loop, The phase shift amount becomes 360 °, and a predetermined oscillation operation is performed by setting the loop gain of the feedback loop at this time to 1 or more.
  • an FM modulator can be constructed by replacing one of the two phase shift circuits 810C included in the oscillator 5J with the phase shift circuit 910C shown in FIG. 37 (B). Can be. Alternatively, one of the two phase-shift circuits 8100C included in the oscillator 5J is replaced with the phase-shift circuit 9110C shown in FIG. 37 (B), and the other is replaced with the phase shifter shown in FIG.
  • the FM modulator may be configured by replacing the phase shift circuit 8101L shown in FIG.
  • FIG. 41 is a circuit diagram of another oscillator configured using two phase shift circuits and a phase inversion circuit.
  • the oscillator 5K shown in the figure is connected in cascade with two stages of the phase shift circuit 830C at the subsequent stage in the oscillator 5H shown in FIG.
  • a phase inversion circuit 880 is connected to the input side, and the output of the subsequent phase shift circuit 830C is returned to the input side of the phase inversion circuit 880 via a feedback resistor 870.
  • an FM modulator is constructed by replacing one of the two phase shifters 830C included in the generator 5K with the phase shifter 930C shown in Fig. 37 ( ⁇ ). can do.
  • one of the two phase shifters 830C included in the oscillator 5 ⁇ is replaced with the phase shifter 930C shown in FIG. 37 ( ⁇ ), and the other is replaced with the phase shifter shown in FIG.
  • the FM modulator may be configured by replacing the phase shift circuit 830 L shown in FIG.
  • the above-mentioned oscillators 5C, 5D, 5E, 5F, 5G, 5H, 5J, 5K, etc. are composed of a non-inverting circuit and two phase shifting circuits or a phase inverting circuit and two phase shifting circuits.
  • the circuit is configured to include a circuit, and a predetermined tuning operation is performed by setting the total phase shift amount to 360 ° at a predetermined frequency by a total of three connected circuits. ing. Therefore, focusing only on the amount of phase shift, there is a certain degree of freedom as to which of the two phase shift circuits is used in the preceding stage or in what order the three circuits described above are connected. Connection order can be determined according to
  • the element constant of each element other than the FET or the variable capacitance diode to which a signal is input from the outside is fixed, and the FM modulation apparatus in which the carrier frequency is fixed is realized.
  • the frequency may be arbitrarily changed by changing each element constant.
  • the FM modulator E1 shown in the 1st-1 ⁇ 1 as an example, by replacing the resistor 16 in the phase shift circuit 10 C with a variable resistor and changing the resistance value, or by changing the phase shift circuit 1
  • the capacitance 14 in 0 C with a variable capacitance element and changing this capacitance
  • the amount of phase shift by the phase shift circuit 10 C is changed, and the FM modulator IS 1
  • the carrier frequency of the output signal can be changed.
  • variable capacitance diode is used as an example of a variable capacitance element.
  • a FET whose gate capacitance can be changed when the gate voltage to be applied is varied is used as a variable capacitance element. It may be.
  • FM modulator ⁇ 1 ⁇ signals input from the outside are joined. Although it is input to the FET of the MOS type, a MOS type F ⁇ F may be used.
  • high stability is realized by configuring an FM modulator using a phase shift circuit 10 C, 130 C, etc. using an operational amplifier.
  • the offset voltage and the voltage gain are not required to have a high performance. Therefore, a differential input amplifier having a predetermined gain may be used instead of the operational amplifier in each phase shift circuit.
  • FIG. 42 ⁇ is a circuit diagram in which portions necessary for the operation of the phase shift circuit in the configuration of the operational amplifier are extracted, and the whole operates as a differential input amplifier having a predetermined gain.
  • the differential input amplifier shown in the figure includes a differential human power stage 100 composed of FETs, a current circuit 102 for supplying a constant current to the differential human power stage 100, and a constant current circuit 102 A bias circuit 104 for applying a predetermined bias voltage to the input terminal and an output amplifier 106 connected to the differential input stage 100 are provided.
  • the multistage amplifier circuit for gaining the voltage gain included in the actual operational amplifier is omitted, and the configuration of the differential input amplifier can be simplified, and the bandwidth can be widened.
  • the upper limit of the operating frequency can be reduced by simplifying the circuit, the upper limit of the output frequency of the FM modulator configured using the differential input amplifier is increased accordingly. be able to. Industrial applicability
  • the present invention it is possible to directly perform FM modulation by changing the resistance and capacitance of a capacitor according to a signal input from the outside, thereby simplifying the circuit configuration of the entire FM modulator. be able to. Also, since an all-pass 3 ⁇ 4 circuit is used, a stable output amplitude can always be obtained regardless of the output frequency.

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  • Amplitude Modulation (AREA)
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Abstract

Un modulateur FM (1) comprend deux circuits déphaseurs (10C, 130C), un transistor à effet de champ FET (35) équipant un circuit résistance-capacité monté dans le circuit déphaseur (130C). La fréquence d'oscillation du modulateur FM (1) est telle que la somme des valeurs de déphasage des deux circuits déphaseurs (10C, 130C) est de 360°. Lorsqu'un signal fourni extérieurement modifie légèrement la résistance canal du transistor à effet de champ (35), le modulateur (1) utilise directement cette modification pour la modulation de la fréquence, les signaux FM produits partant d'une borne de sortie (92).
PCT/JP1996/001706 1995-11-16 1996-06-20 Modulateur fm WO1997018625A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU61378/96A AU6137896A (en) 1995-11-16 1996-06-20 Fm modulator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP7/322222 1995-11-16
JP32222295 1995-11-16

Publications (1)

Publication Number Publication Date
WO1997018625A1 true WO1997018625A1 (fr) 1997-05-22

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PCT/JP1996/001706 WO1997018625A1 (fr) 1995-11-16 1996-06-20 Modulateur fm

Country Status (3)

Country Link
AU (1) AU6137896A (fr)
TW (1) TW297980B (fr)
WO (1) WO1997018625A1 (fr)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5029024A (fr) * 1973-07-18 1975-03-24
JPS52120657A (en) * 1976-04-02 1977-10-11 Fujitsu Ltd Voltage control oscillator
JPS5331947A (en) * 1976-09-04 1978-03-25 Nippon Gakki Seizo Kk Phase modulator circuit
JPS54959A (en) * 1977-06-06 1979-01-06 Mitsubishi Electric Corp Phase modulation circuit
JPS5427306A (en) * 1977-08-02 1979-03-01 Nec Corp Instantaneous frequency deviation control circuit
JPS5947483B2 (ja) * 1974-07-10 1984-11-19 エヌ・ベー・フイリツプス・フルーイランペンフアブリケン ブリツジの不平衝を周波数変化に変換する回路配置
JPH0575387A (ja) * 1991-09-17 1993-03-26 Sanyo Electric Co Ltd 可変遅延回路
JPH05183406A (ja) * 1991-12-27 1993-07-23 Nec Eng Ltd 自動位相補正回路

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5029024A (fr) * 1973-07-18 1975-03-24
JPS5947483B2 (ja) * 1974-07-10 1984-11-19 エヌ・ベー・フイリツプス・フルーイランペンフアブリケン ブリツジの不平衝を周波数変化に変換する回路配置
JPS52120657A (en) * 1976-04-02 1977-10-11 Fujitsu Ltd Voltage control oscillator
JPS5331947A (en) * 1976-09-04 1978-03-25 Nippon Gakki Seizo Kk Phase modulator circuit
JPS54959A (en) * 1977-06-06 1979-01-06 Mitsubishi Electric Corp Phase modulation circuit
JPS5427306A (en) * 1977-08-02 1979-03-01 Nec Corp Instantaneous frequency deviation control circuit
JPH0575387A (ja) * 1991-09-17 1993-03-26 Sanyo Electric Co Ltd 可変遅延回路
JPH05183406A (ja) * 1991-12-27 1993-07-23 Nec Eng Ltd 自動位相補正回路

Also Published As

Publication number Publication date
AU6137896A (en) 1997-06-05
TW297980B (en) 1997-02-11

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