JPH0884092A - Transmitter-receiver - Google Patents

Abstract

PURPOSE: To provide simple a transmitter-receiver improved in reception characteristics and capable of switching transmission and reception at a high speed by sharing an RF band oscillation circuit used at least for transmission/ reception frequency conversion and generating transmission IF signals to be required at the time of the transmission from at least one referece signal source already present inside the transmitter-receiver only at the time of the transmission in the transmitter-receiver of a high frequency band. CONSTITUTION: The reference signal source 1 of a phase-locked oscillation circuit 4 serving for both transmission and reception performs oscillation at all times and local oscillation signals generated by the reference signals are supplied to reception and transmission frequency conversion circuits 5 and 6. A transmission IF sine wave generation circuit 7 generates IF signals by signals from the reference signal source 1 and the transmission IF sine wave generation circuit 7 supplies IF frequency signals to the next stage only at the time of the transmission by transmission/reception switching signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a transmitter / receiver having a transmitting function and a receiving function mainly used for wired and wireless communication.

[0002]

2. Description of the Related Art FIG. 16 is a block diagram of a basic configuration of a transmission / reception device used for wireless communication or the like.

The transmitter 82 includes a transmission IF oscillation circuit 83 (oscillation frequency f _ITX ), a modulation circuit 9 for modulating the sine wave output of the transmission IF oscillation circuit 83, a transmission frequency conversion circuit 6 connected to this, and a transmission circuit. A transmission local oscillation circuit (oscillation frequency f that gives a local oscillation signal to the frequency conversion circuit 6
_LTX ) 84. At the time of transmission, the modulation circuit 9
The output sine wave signal of the F oscillation circuit 83 (f = f _ITX ) is modulated by the transmission baseband signal which is the transmission information, and the output IF signal and the output IF signal of the transmission local oscillation circuit 84 are modulated. Is converted to a desired transmission RF frequency (f = f _TX ) by the transmission frequency conversion circuit 6 and then transmitted from the transmission terminal 11.

The receiving section 85 includes a receiving frequency converting circuit 5,
A local oscillator circuit 86 for receiving a local oscillation signal
Swing frequency f_LRX), And the reception frequency conversion circuit 5
The demodulator 8 is configured as shown in FIG. Receiving terminal 10 when receiving
The received RF signal (f =
f_RX) And the output sine wave (f =
f _LRX) And the demodulator 8 operates in the reception frequency conversion circuit 5.
Possible reception IF frequency f_{IR X}Convert up to. IF reception
Signal is input to the demodulator 8 and demodulated to obtain desired reception information.
To obtain a received baseband signal. This demodulator circuit smells
Characteristics such as ease of realization, interference resistance, demodulation sensitivity, etc.
The operating frequency (f_IRX) Is 100 tens of M
Hz is the limit, and the reception frequency f_RXIs my
If the frequency is extremely high, such as the black band, the received local frequency
Also needs to be in the microwave band.

[0005] Here, the half-duplex system, which is commonly used, is used.
In the transmission system, the transmission frequency f_TXAnd f_RXAre the same
Therefore, the transmission local frequency f_LTXAnd receive local frequency
Number f _LRXAlso becomes the same, and the transmission local oscillation circuit 84 also has a pole.
It must be a high frequency oscillator circuit. Only
However, oscillators in the RF band, especially in the microwave band and above, are usually
It is expensive and has a large shape. Also, data communication, etc.
For applications, it is required to have good frequency stability and
The configuration becomes complicated due to stabilization of the vibration frequency.

Therefore, conventionally, the number of RF band oscillators in the apparatus has been reduced by using the configuration shown in FIGS.

FIG. 17 shows a first conventional example in which the transmission local oscillation circuit 84 and the reception local oscillation circuit 86 shown in FIG. 16 are shared by a single transmission / reception RF oscillation circuit 87. In this case, since f _IRX is not more than 100 tens MHz as described above, the oscillation frequency of the transmission / reception RF oscillation circuit 87 is also in such a high frequency band, and the transmission IF oscillation circuit 83
Is the reception IF frequency (f _IRX ) if the same frequency is transmitted and received
Will oscillate. Therefore, an IF modulation circuit operating at f _IRX is used as the modulation circuit 9 in FIG.

By the way, in general, an RF modulation circuit that operates in the VHF band or higher for modulating a sine wave signal in the RF band can be easily realized, and by using this, a reception local oscillator circuit output sine wave signal and an RF modulation circuit input. It is also possible to share the sine wave signal with one RF band oscillator circuit output.

FIG. 18 shows the construction of a second embodiment of such a system. RF oscillation circuit 8 for both transmission and reception
No. 7 oscillates in the RF band as in the first conventional example. In this case, the output sine wave signal of the transmission IF oscillation circuit 83 is directly applied to the IF input terminal of the transmission frequency conversion circuit 6. An RF modulator 12 is connected between the transmission / reception RF oscillation circuit 87 and the transmission frequency conversion circuit 6, and a transmission baseband signal is sent to the RF modulator 12.

FIG. 19 shows a third conventional example, which is an RF modulator 12.
18 and a transmission / reception oscillation circuit 88 are used, and the transmission frequency conversion circuit and the transmission IF oscillation circuit are omitted.
Is different from the RF modulator 12 in which the modulation circuit operates at f _TX.
That is, the direct modulation is performed at the desired transmission frequency f _TX during transmission. That is, the transmission / reception RF oscillation circuit 88
Oscillates at a frequency of f _LRX at the time of reception and f _TX at the time of transmission, and switches the frequency by a transmission / reception switching signal. Therefore, the transmission IF oscillation circuit 83 and the transmission frequency conversion circuit 6 shown in FIG. 18 are unnecessary.

In the first and second conventional examples shown in FIGS. 17 and 18, the number of oscillation sources in the RF band is reduced by one compared with the basic configuration shown in FIG. In the third conventional example, one RF band oscillator and one transmission IF oscillator are reduced.

[0012]

By the way, when the communication is carried out in the half-duplex system as described above, the transmission / reception switching time is particularly important. In applications such as high-speed packet data communication, this switching time is the data transmission time. Compared with the speed or the packet length, it cannot be ignored, and the transmission efficiency is reduced. Specifically, it is no exaggeration to say that the transmission / reception switching time is determined by the characteristics such as the rise time and frequency setting of the oscillation circuit in the device. Therefore, in order to shorten the switching time,
It is desirable that the oscillator in the device always operates regardless of transmission and reception, and that the frequency is fixed in order to shorten the frequency setting time.

In the first conventional example of FIG. 17, when the transmission / reception frequencies f _TX and f _RX are the same, in order to reduce the transmission / reception switching time, the transmission / reception R which is an oscillation circuit in the device is used for the above reason.
It is desirable that the F-combined oscillation circuit 87 and the transmission IF oscillation circuit 83 always operate regardless of transmission / reception, and the transmission / reception R
It is desirable that the oscillation frequency of the F oscillation circuit 87 is selected to be the same for transmission and reception. In this case, the transmission and reception IF frequencies are also equal,
The transmission IF oscillating circuit 83 oscillates at the demodulator operating frequency during reception, and acts as an interference source for the demodulator 8. Generally, the demodulator 8 has a very high sensitivity, and the transmission I existing in the device is
No matter how strong the shield for avoiding the interference from the F oscillation circuit 83 is, the slight signal leakage causes the deterioration of the reception characteristics.

Also in the second conventional example of FIG. 18, the transmission I
The F oscillating circuit 83 functions as an interference source at the time of reception, and causes deterioration of the reception characteristic for the same reason as above.

In the third conventional example of FIG. 19, the signal source that interferes with the demodulator 8 at the time of reception does not exist in the apparatus, but when the frequency of transmission and reception is the same, the oscillation of the transmission / reception IF oscillating circuit 88 is inevitable. The frequency must be shifted by the reception IF frequency f _{IRX at the} time of transmission / reception switching, and a frequency setting time for this is required, so that the transmission / reception switching time can be shortened essentially.

Further, as apparent from FIGS. 17 to 19, focusing on the number of RF band oscillation circuits, in the first or second method capable of shortening the transmission / reception switching time, one RF band transmission source and transmission IF transmission are provided. A minimum of one source and a total of two sources was required.

It is an object of the present invention to provide a transmission / reception device of a high frequency band, which also serves as at least an RF band oscillation circuit used for transmission / reception frequency conversion, and which has at least one transmission IF signal already present in the device for transmission. An object of the present invention is to provide a transmission / reception device that is simple and has good reception characteristics and can switch between high-speed transmission and reception by generating only from a reference signal source during transmission.

[0018]

In the transmitting / receiving apparatus of the present invention, a reference signal source existing in the apparatus is utilized, whereby a transmitting IF frequency signal is generated only during transmission, and the transmitting / receiving apparatus in the apparatus is irrespective of transmission / reception. The reference oscillation source is always operated, and the component that interferes with the demodulator is not generated during reception. Further, the frequency of the reference oscillation source and the transmission IF signal frequency are selected in a specific relation, and the reference signal source output is multiplied,
By dividing, mixing, or combining these, an IF signal with a frequency different from that of the reference signal source can be generated.

[0019]

In a transmitter / receiver generally used for data communication and other wireless communication, good frequency stability is required. Therefore, the oscillator in the transmitter / receiver is a reference oscillator such as a crystal oscillator or the reference in the RF band. A phase locked oscillator that is phase locked to the oscillator is used. Further, when a digital signal processing circuit is provided in the transmitter / receiver, it usually has a reference clock for determining the operation timing thereof, and generally at least one reference signal is provided in the transmitter / receiver. There is a source. In such a transmission / reception device according to the present invention, the reference signal source in the device is always operated regardless of transmission / reception, and even if the oscillation frequency is selected to be the same for transmission / reception, a transmission IF signal is not generated from the reference signal at the time of reception. Thus, when receiving, an interference signal having a transmission IF frequency component equal to the reception IF frequency component that deteriorates the demodulation characteristic is not generated. Further, since multiplication, frequency division, mixing, or a combination thereof is used as the transmission IF signal generating means, by adopting a circuit element having a high response time, the transmission / reception switching time is hardly affected.
Further, since the transmission IF signal which has been conventionally required is always generated from the reference signal source existing in the device, the number of transmission sources in the device can be minimized.

[0020]

1 is a block diagram of a first embodiment of a transmitting / receiving apparatus according to the present invention. The present apparatus is composed of a reference oscillator 1, a phase-locking circuit 2 connected to the reference oscillator, and a phase-locking oscillator circuit 4 serving as a local oscillator which oscillates in the RF band and which is a local oscillator oscillating in an RF band, and a receiver connected thereto. The frequency conversion circuit 5, the transmission frequency conversion circuit 6, the demodulator 8 connected to the reception frequency conversion circuit 5, and the transmission IF which is a means for generating a transmission IF sine wave signal from the output of the reference oscillator 1 in the local oscillator. A sine wave generating circuit 7 and a reception IF provided between the sine wave generating circuit 7 and the transmission frequency conversion circuit 6.
The IF modulation circuit 9 operates at the frequency f _IRX .

In this embodiment, the RF sine wave signal output of the phase-locked oscillator circuit 4 for both transmission and reception is divided and applied as a transmission and reception RF local signal of the reception frequency conversion circuit 5 and the transmission frequency conversion circuit 6. On the other hand, the output of the reference oscillator 1 in the transmission / reception phase synchronization circuit 4 is input to the transmission IF sine wave generation circuit 7, and a transmission IF sine wave signal whose frequency is f _ITX = f _IRX is obtained as its output. As will be described later in detail, the transmission IF sine wave generation circuit 7 is operated only at the time of transmission by the transmission / reception switching signal, or its output is blocked only at the time of reception by a signal switch or the like, and the transmission IF sine wave signal is transmitted only at the time of transmission. Generate and output.

In the reception state, the reception signal input from the reception terminal 10 is mixed by the reception frequency conversion circuit 5 with the sine wave signal output from the transmission / reception phase-locked oscillation circuit 4 and converted into a reception IF signal. The converted reception IF signal is input to the demodulator 8 and the desired reception baseband signal is obtained as its output. At this time, since the transmission IF sine wave generation circuit 7 is in the non-operating state or the non-output state as described above, it has a reception IF frequency component that causes interference to the demodulator even when the oscillator in the apparatus is constantly operated. There is no signal.

Next, in the transmission state, the transmission I generated by the transmission IF sine wave generation circuit 7 in the IF modulator 9 is transmitted.
The F sine wave signal is modulated with the transmission baseband signal to obtain a modulated signal. By mixing this modulated signal and the sine wave signal output from the phase-locked oscillator circuit 4 for both transmission and reception, the transmission frequency conversion circuit 6 obtains a desired transmission signal, and the transmission terminal 11
Send out. In the present embodiment, since the transmission IF sine wave signal is generated from the reference signal already existing in the device, the transmission IF oscillation circuit which has been conventionally required becomes unnecessary,
It is possible to minimize the number of oscillation circuits in the device.

FIG. 2 is a block diagram of a second embodiment of the transmitting / receiving apparatus according to the present invention. Transmission and reception phase-locked oscillator circuit 4, reception frequency conversion circuit 5, transmission frequency conversion circuit 6,
The demodulator 8 and the transmission IF sine wave generation circuit 7 are the same as those in the first embodiment, except that the IF modulation circuit 9 is used instead of the sine wave in the RF band. The RF modulation circuit 12 that modulates a signal is provided in the preceding stage of the transmission frequency conversion circuit 6. In this embodiment, the output of the transmission / reception phase-locked oscillator circuit 4 is divided and input to the reception frequency conversion circuit 5 and the RF modulation circuit 12, and the transmission IF sine wave generation circuit is produced by the same method as in the first embodiment. The transmission IF sine wave signal generated in 7 is directly transmitted to the transmission frequency conversion circuit 6
To enter. Similar to the first embodiment, the transmission IF sine wave generation circuit 7 generates and outputs the transmission IF sine wave signal only during transmission by the transmission / reception switching signal.

The receiving operation in this embodiment is the same as the first embodiment.
Same as the example, but in the transmitting state, the dual-use phase
RF band sine wave signal divided from the output of the synchronous oscillation circuit 4
(F _LRX) To the RF modulation circuit 12 with the transmission baseband signal
, And obtain the RF modulated wave as its output.
It RF modulated signal and transmission IF sine wave thus obtained
The transmission IF sine wave signal generated by the generation circuit 7 is transmitted.
By mixing in the wave number conversion circuit 6, the desired transmission signal
Convert to.

FIG. 3 is a block diagram of the third embodiment.
When the modulation method is FM or PM, it is possible to replace the RF modulation circuit 12 surrounded by the dotted line in FIG. 2 and the transmission / reception phase-locked oscillation circuit 4 with the direct phase-locked modulation circuit 13 shown in FIG. is there. The direct phase-locked modulation circuit 13 comprises a reference oscillator 1, a phase-locked circuit 2 and a VCO 3.
In addition to the oscillation circuit shown in FIG. 2, a waveform shaping circuit 14 including a level shift, an LPF and the like for shaping a transmission baseband signal, and a phase synchronization circuit 2 and V connected to the waveform shaping circuit 14.
It is configured by adding an adder 15 added between CO3.

At the time of reception, the modulation circuit 13 has a transmission base.
Used without modulation without applying band signal. in this case,
The VCO 3 has a synchronization control voltage output from the phase synchronization circuit 2.
Pressure V _LIs applied, and the output of the modulator 13 is the reference signal.
Frequency f which is phase-locked to_LRXBecomes a sine wave of
Path 13 acts as a receiving local oscillator.

At the time of transmission, in addition to the synchronous control voltage V _L , the baseband modulation signal V _m whose waveform has been shaped by the waveform shaping circuit 14 is superimposed by the adder 15, and V _L + V _m is applied to the VCO 3. Since the phase synchronization circuit 2 has no sensitivity to the modulation signal V _m , the output of the modulation circuit 13 becomes an FM or PM wave at the frequency f _LRX . Here, the waveform shaping circuit 14 may be omitted if necessary.

Also in the second and third embodiments described above,
Since the transmission IF sine wave generation circuit 7 is put into a non-output state at the time of reception, as in the first embodiment, even if the oscillator in the apparatus is always operated regardless of transmission / reception, there is a f _IRX component which becomes a problem at the time of reception. There is no interfering signal. Further, since the transmission IF sine wave signal is generated from the reference signal already existing in the device, the number of oscillators in the device is minimized.

Further, in the actual transmitting / receiving device for communication, FIG.
Various circuits are added to the configurations of 3 to 3. If the added circuit includes reference signal sources, these reference signal sources can also be used. 4 and 5 are examples thereof.

FIG. 4 is a block diagram of the fourth embodiment.
This is a case in which an up / down converter 28 for making a transmission / reception signal a higher frequency is added to the device as shown in FIGS. Here, the up / down converter 28 is
It comprises an up converter 16, a down converter 17, a local phase-locked oscillation circuit 18 for supplying signals to these, and a transmission / reception changeover switch 19 provided between the antenna and the up converter 16 and the down converter 17. The local phase-locked oscillator circuit 18 has the same configuration as the transmission / reception phase-locked oscillator circuit 4 shown in FIGS. 1 to 3, and includes a reference oscillator 20, a phase-locked loop circuit 21, and a VCO 22. In this case, the output of the reference oscillator 20 in the local phase locked oscillator circuit 18 can be input to the transmission IF sine wave generation circuit 7 to generate a transmission IF sine wave signal.

FIG. 5 is a block diagram of the fifth embodiment.
This is a case where a digital signal processing circuit 24 as an interface with a control terminal 23 such as a computer is added to the apparatus as shown in FIGS. Generally, such a digital signal processing circuit has a reference clock 25 that always determines its timing. In this embodiment, this output is input to the transmission IF sine wave generation circuit 7 to obtain a transmission IF sine wave signal.

Although the case where the IF modulation circuit 9 is used is shown in FIGS. 4 and 5, the same can be considered when the RF modulation circuit is used.

In the case of FIGS. 4 and 5, the transmission / reception phase-locked oscillator circuit 4 in the first to third embodiments may be replaced with a normal oscillator having no reference oscillator and having low frequency stability.

FIG. 6 is a block diagram of the sixth embodiment, which is an example in which a plurality of reference signal sources are present in the transmitter / receiver. In this embodiment, the reference signal sources 27-1 to 27-k in the device are used.
(Oscillation frequency f _r1 , f _r2 ... _frk ) is characterized in that the transmission IF sine wave signal is obtained, and the transmission IF sine wave generation circuit 26 receives the k reference signal source outputs and outputs the transmission IF sine wave signals to the outputs. The k-input 1-output circuit has a function of generating and outputting a sine wave signal only during transmission. Although this embodiment also shows the case where the IF modulation circuit 9 is used, the same applies to the case where the RF modulation circuit is used, as in the fourth and fifth embodiments.

The transmission IF sine wave generating circuit 7 according to the present invention employs a circuit having a high response time, and the reference signal in the first to fifth embodiments is multiplied by N or M times. , And the reference signal in the sixth embodiment by a factor of N or M, and selecting the reference signal, N _j or M _j (j = 1).
By changing (k) to (k), the frequency can be switched more easily and at a higher speed than in the past.

FIG. 7A is a block diagram of the seventh embodiment. This is a case where a transmission IF sine wave generation circuit that multiplies the frequency of the reference signal by M is used. Using the IF modulation circuit 9, the transmission IF frequency f _ITX (that is, the reception IF frequency = f _IRX )
The relationship between the reference signal frequency f _r to be the case you choose to the following relationship.

[0038]

(Equation 5)

In this case, the transmission IF sine wave generation circuit uses the frequency M times circuit 30. This frequency M times circuit 30
Is a signal cutoff switch 32, 35 provided on the input / output side.
And a band-multiplier circuit 34 having an M-multiplier 33 and a center-frequency M · F _r band-pass filter (BPF) and an amplifier. The M multiplier / multiplier 33 intentionally distorts the input output of the reference oscillator 31 to generate a harmonic component.
Specifically, as shown in FIG. 7 (b), AB class, B class
Class 37 or Class C non-linear amplifier 37, FIG.
A multiplier 38 such as a varactor diode shown in (c), an inverter 39 such as a simple CMOS logic shown in FIG. 7D, or a sine such as a buffer 40 shown in FIG. 7E. A wave-square wave shaping circuit may be used.

In this embodiment, at the time of transmission, the signal cut-off switches 32 and 35 of the frequency M-multiplier circuit 30 are rendered conductive by the transmission / reception switching signal, and the M-multiplier 33 and the band amplifier circuit 34 are put into the operating state to enable the output. To Generally, the output of the M-multiplier 33 is 1, 2, or 3 times the input reference signal frequency.
Various harmonic components of ... are included, and the band amplification circuit 34 attenuates the components other than the M-fold harmonic,
Only the M-times harmonic is input to the IF modulator 9 as a desired transmission IF sine wave signal.

At the time of reception, by the transmission / reception switching signal,
The signal cut-off switches 32 and 35 are cut off, the M-multiplier 33 and the band amplification circuit 34 are deactivated, and the transmission I
The F frequency f _ITX (reception IF frequency f _IRX ) component is not generated, and interference with the demodulator, which has been a problem in the past, does not occur. Here, if necessary, the signal cutoff switch 32 on the input side may be omitted, and the band amplification circuit 34 may be a simple bandpass circuit having no amplifier. Since the signal cut-off switch is provided, the M-multiplier 33 and the band amplification circuit 34 may be operated regardless of transmission / reception.

FIG. 8 is a block diagram of the eighth embodiment.
In this case, the reference signal frequency is set to 1 / N to generate the transmission IF sine wave signal. The transmission IF frequency f _ITX and the oscillation frequency f _r of the reference oscillator are selected in the following relationship.

[0043]

(Equation 6)

In this case, the transmission IF sinusoidal wave generation circuit uses the frequency 1 / N circuit 41. Frequency 1 / N circuit 41
Is a signal interruption switch 45, 46 provided on the input / output side.
N frequency divider 42 consisting of CMOS digital programmable counter or the like provided therebetween, the center frequency f _r / N of the BPF and the bandpass amplifier comprising an amplifier 43
It consists of a cascade connection. This 1 / N frequency circuit uses the same method as in the seventh embodiment to enable output only during transmission by a transmission / reception switching signal. Therefore, at the time of transmission, the reference signal is converted into a pulse having a frequency of 1 / N by the N frequency divider 42, and the band amplification circuit 43 and the signal cutoff switch 46.
Then, a transmission IF sine wave signal having a desired level is generated. At the time of reception, the 1 / N frequency circuit, which is the transmission IF sine wave generation circuit, is in the non-output state as in the seventh embodiment.
Interference to the demodulator can be avoided.

Also in this embodiment, as shown in the seventh embodiment, one of the signal cutoff switches 45 and 46 may be omitted if necessary, and the band amplification circuit may be a band pass circuit. Further, since the signal cutoff switch is provided, the N frequency divider 42 and the band amplification circuit 43 may always operate.

FIG. 9A is a block diagram of the ninth embodiment, which shows a case where the seventh and eighth embodiments are combined. The reference frequency f _r and the reception IF frequency f _IRX, that is, the transmission IF frequency f _ITX have the relationship of the following expression (3).

[0047]

(Equation 7)

In the figure, the transmission IF sine wave is transmitted by the frequency N / M multiplication circuit 47 which is a cascade connection of the frequency M / multiplication circuit 30 of the seventh embodiment and the frequency 1 / N circuit 41 of the eighth embodiment. A generation circuit is configured. Here, when focusing on the first circuit 41 of the frequency N times, the output of the N divider 42 in the circuit is a pulse waveform of repetition period N / f _r, various harmonics of the frequency components f _r / N Is included. Therefore, by changing the center frequency of the bandpass amplifier 43 in first circuit 41 frequency N times to M · f _r / N, and therefore can be used as M times the circuit 47 of the frequency N times in this embodiment .

FIG. 9B is a block diagram of an example thereof, in which the N divider 42 is provided between the signal cutoff switches 45 and 46.
And the band amplification circuit 48 are connected. Band amplification circuit 4
Center frequency of 8 is in the M · f _r / N.

In the seventh to ninth embodiments, the center frequency variable BPF is used as the BPF in the band amplifying circuits 34, 43, 48 to change the initial values of the multiplier and the frequency divider so that the BPF can be easily adjusted. And, it becomes possible to switch the frequency at high speed.

FIG. 10 is a block diagram of the tenth embodiment. This is the case of the transmission IF sine wave generation circuit combining the sixth embodiment and the ninth embodiment. relationship between the oscillation frequency f _r1 ~f _rk transmission IF frequency f _ITX of the k reference oscillator,

[0052]

[Equation 8]

It is assumed that k number of frequencies N _j fraction of M _j times circuit (j = 1 to k) 51-1 to 51-k and k inputs and one output of the frequency mixer 49 and the center frequency (4) of f _ITX is a BPF And a band amplification circuit 50 composed of an amplifier. Signal cut-off switches 52-1 to 52 on the input section
-K is provided, and the signal cutoff switch 5 is provided at the output.
3 is provided. In this embodiment, the j-th reference signal source output is input to the input j of this circuit to generate the transmission IF sine wave signal defined by the equation (4). At the time of reception, similarly to the seventh to ninth embodiments, the transmission I
By setting the F sine wave generation circuit 26 in the non-output state, interference during reception is suppressed. Also in this embodiment, the seventh to ninth
The frequency can be switched easily and at high speed by changing N _j and M _j as in the above embodiment. In addition to this, in addition to this, the frequency of N _j of M _j multiplication circuits 51-i to 51-k is increased. Signal cut-off switches 52-1 to 52- provided on the input part
By cutting off any of k, k input 1 output transmission IF
The output frequency of the sine wave generation circuit 26 can be shifted by M _j · f _r / N _{j, and} high-speed frequency switching by this method is also possible.

The seventh to tenth embodiments are examples using the IF modulation circuit 9, and even when the RF modulation circuit 12 or the direct phase synchronization modulation circuit 13 is used, the transmission IF sine wave generation circuit is By using the specific examples shown in the seventh to eighth embodiments, it is possible to obtain the transmission IF sine wave signal different from the frequency of the reference signal in the same manner as above.

Next, the frequency conversion circuit for transmission and reception will be described. 11A and 11B are block diagrams of the reception frequency conversion circuit 5 and the transmission frequency conversion circuit 6 according to the first to tenth embodiments, respectively. Both of them have two input band amplification circuits 55, 61 and 68, 7 respectively.
It is composed of a total of three band amplification circuits, one and one output band amplification circuits 58 and 65, and two-input and one-output mixers 62 and 72 for outputting the sum or difference of the frequencies of the two inputs.

FIG. 11A shows a reception frequency conversion circuit. When the reception signal is input to the terminal A and the reception local sine wave signal is input to the terminal C, the reception IF signal is output to the terminal B. The input band amplification circuit 55 to which the received signal is input has a band RF amplification circuit centered on the reception frequency f _RX , and the input band amplification circuit 61 to which the received local signal is input has a band RF amplification centered on the reception local frequency f _LRX. Circuit.
The output band amplification circuit 58 is a band IF amplification circuit whose operating frequency is the reception IF frequency f _IRX since its output is connected to the demodulator.

FIG. 11B shows a transmission frequency conversion circuit, in which a signal having a transmission IF frequency component at the terminal E,
When a signal having a transmission local frequency component is input to the terminal F, a signal having a desired transmission frequency is output to the terminal D. Here, when the transmission and reception have the same frequency, the input band amplification circuit 6
8 is a band IF amplifier circuit centered on the transmission IF frequency, input band amplifier circuit 71 is a band RF amplifier circuit centered on the reception local frequency f _LRX , and an output band amplifier circuit 65.
Is a band RF amplifier circuit centered on a desired transmission frequency. Therefore, the functions of the two RF amplifier circuits and one IF amplifier circuit used for both are exactly the same. Also,
When the receiving RF signal is input to the input 1 and the local RF signal is input to the input 2, the receiving mixer 62 outputs a frequency difference signal between these two input signals. On the other hand, when the input mixer 3 inputs the IF band signal and the input 4 inputs the RF band signal, the transmission mixer 72 outputs the frequency sum signal of these two input signals. Generally, a mixer utilizes the input / output non-linearity of a frequency mixing element used, and when two signals are input, a sum of frequencies of the two input signals or a frequency difference component is generated at the output. Therefore, the difference between the mixer for reception and the mixer for transmission is that only the conversion efficiency for the frequency difference component for reception and the frequency sum component for transmission is designed with priority, and functionally They are the same.

As is clear from the above and FIG. 11, the difference between the receiving frequency converting circuit and the transmitting frequency converting circuit is that the combination of the design frequency of the mixer circuit and the amplifier circuit connected to the input / output of the mixer is different. Only. Therefore, it can be used also as a mixer.

FIG. 12 is a block diagram in the case where the mixer for transmission and the mixer for reception are both used. A transmitter / receiver mixer 73 having characteristics of both a transmitter and a receiver, a signal changeover switch 74 to 77, a transmitter / receiver RF band amplifier circuit 78 which operates in a high frequency range at a transmitter / receiver frequency, and a mixer 73 which operates at a receiver local frequency. RF band amplification circuit 80 to connect
And an IF band amplification circuit 79 operating at the reception IF frequency
12, the transmission frequency conversion circuit and the reception frequency conversion circuit are shared by one transmission / reception frequency conversion circuit 81, so that the circuit can be simplified, downsized, and reduced in cost. Note that FIG. 12 shows a transmitting state, and at the time of reception, the signal changeover switches 74 to 77 are connected in opposite directions, and the input / output connection directions of the band amplification circuits 78 and 79 are opposite.

In FIG. 12, a local sine wave signal is supplied from the terminal K to the input 6 of the transmission / reception mixer 73 via the RF band amplification circuit 80. The input 5 of the transmission / reception mixer 73 is connected to the output terminal of the transmission / reception RF band amplification circuit 78 via the signal changeover switch 75 (during reception), or connected to the output terminal of the IF band amplification circuit 79 via the switch 77. Will be done (when sending). The output 3 of the transmission / reception mixer 73 is connected to the input terminal of the transmission / reception RF band amplification circuit 78 via the signal changeover switch 74 (during transmission) or the input terminal of the IF band amplification circuit 79 via the signal changeover switch 76. Connected to (when receiving). RF band amplification circuit 7 for both transmission and reception
The output terminal of 8 is connected to the terminal G via the signal switch for transmitting 75, the transmission signal is output from here, and its input terminal is connected to the terminal H via the signal changing switch for receiving 74 and receiving from here. A signal is input. Dual-use I / O
The output terminal of the F band amplifier circuit 79 is connected to the terminal I via the signal switch for reception 77, the reception IF signal is output from this terminal, and the input terminal is connected to the terminal J via the signal switch for transmission 76. The signal of the transmission IF frequency component is input from here.

FIG. 13 is a block diagram of a transmission / reception frequency conversion circuit obtained by modifying the circuit of FIG. The difference from FIG. 12 is that the mixer is a bidirectional mixer 82. In the bidirectional mixer 82, one of the three terminals is an RF local signal common input terminal, and the remaining two terminals can both input and output. That is, when a signal is applied to the input / output 1, a converted output is obtained to the input / output 2 and a converted output is obtained to the input / output 1 when a signal is applied to the input / output 2, respectively. Can be obtained.

Here, as in the second and third embodiments using the modulation circuit in RF shown in FIGS. 2 and 3, the transmission IF sine wave signal which is the output of the transmission IF sine wave generation circuit 7 is When the transmission / reception frequency conversion circuit 81 shown in FIGS. 12 and 13 is applied to the configuration directly input to the transmission frequency conversion circuit 6, each transmission IF sine wave generation circuit 30 described in the seventh to tenth embodiments. , 41, 47, and 26, the band amplification circuits 34, 43, 48, and 50 can be commonly used by the IF band amplification circuit 79 of the transmission / reception frequency conversion circuit 81, which further simplifies, downsizes, and lowers the circuit. Cost can be expected.

FIG. 14 shows the eleventh embodiment which also serves as a circuit.
2 is a block diagram of the embodiment of FIG. 2 and is a simplified version of the second embodiment of FIG. 2 using a transmission / reception frequency conversion circuit 81. 2 is different from the circuit of FIG. 2 in that instead of the reception and transmission frequency conversion circuits 5 and 6, a transmission / reception frequency conversion circuit 81 is provided, which is connected to the demodulator 8, the transmission IF sine wave generation circuit 7 and the RF modulation circuit 12. That is what is being done. Further, the terminal K of the transmission / reception frequency conversion circuit 81 is connected by switching with the RF modulator 12 or the transmission / reception phase-locked oscillation circuit 4 by a switch 90. The transmission / reception switching signal is supplied to the transmission IF sine wave generation circuit 7, the RF modulator 12, the switch 90, and the transmission / reception frequency conversion circuit 81 to control them. In this embodiment, the output of the transmission / reception RF phase-locked oscillation circuit 4 is input to the RF modulation circuit 12 during transmission. The reception local sine wave signal which is an unmodulated carrier at the time of reception is transmitted / received by the frequency conversion circuit 81 K.
In order to apply to the terminal, the bypass switch 90
The input / output of the modulation circuit 12 is bypassed, and the modulation circuit is put into a non-operation state or a non-modulation state when receiving the transmission / reception switching signal. Note that, depending on the case, the bypass switch 90 may be omitted, and the RF modulation circuit 12 may be constantly operating.

FIG. 15 is a block diagram of the twelfth embodiment. The transmission / reception frequency conversion circuit 81 is applied to the embodiment using the direct phase synchronous modulation circuit 13 of FIG. 3 to simplify the circuit. It is a thing. 3 is different from the circuit of FIG. 3 in that instead of the transmission and reception frequency conversion circuits 6 and 5, a transmission / reception frequency conversion circuit 81 is provided, which is a demodulator 8,
That is, it is connected to the transmission IF sine wave generation circuit 7. A transmission / reception switching signal is supplied to the RF modulation circuit, the transmission IF sine wave generation circuit, and the transmission / reception frequency conversion circuit,
Control these. In this embodiment, as described above, at the time of reception, the input of the transmission baseband signal to the phase synchronous modulator circuit 13 is stopped, or the operations of the adder 15 and the waveform shaping circuit 14 are made inactive by the transmission / reception switching signal. As a result, the unmodulated reception local signal is applied to the K terminal of the transmission / reception frequency conversion circuit 81.

11th and 12th of FIGS. 14 and 15
In the embodiment using the frequency conversion circuit for both transmission and reception, the reception I
When the F frequency and the reference signal frequency have the relationship of the expression (1), the transmission IF sine wave generation circuit 7 in the apparatus operates the M multiplier 33.
Further, in the case of the relationship of the formula (2), it can be realized only by the N frequency divider 42, and is a frequency M times circuit which is the transmission IF sine wave generation circuit described in the seventh and eighth embodiments. The band amplification circuits 34 and 43 inside the circuit 30 and the 1 / N frequency circuit 41 are unnecessary. Similarly, when the relationship between the reception IF frequency and the reference signal is expressed by the equations (3) and (4), the transmission / reception frequency conversion circuit is used to make the M-times circuit 47 for the frequency N or the transmission IF sine wave generation circuit 26. The band amplification circuits 48 and 50 in the inside can be omitted. Therefore, in the embodiment using the eleventh and twelfth transmission / reception frequency conversion circuits, the circuit of the transmission / reception device can be extremely simplified, which is very advantageous in terms of circuit area, number of parts, and cost compared with the conventional case. . Further, there is also an advantage that a power divider or the like for dividing the output of the RF oscillation circuit for both transmission and reception, which has been conventionally required, into a transmission system and a reception system is unnecessary.

[0066]

EFFECTS OF THE INVENTION According to the present invention, 1) a transmission IF that is required at the time of transmission in a transmission / reception device that uses a reception IF demodulator and uses an RF oscillation circuit for both transmission and reception.
By generating the sine wave signal from the reference signal source already existing in the device, the number of oscillation circuits in the device can be reduced.

2) The transmission IF sine wave generation circuit for generating the transmission IF sine wave signal is put into a non-output state at the time of reception to eliminate the interference component to the demodulator, and the transmission / reception switching time is almost deteriorated. Absent.

3) High-speed frequency switching is possible by switching the constant in the transmission IF sine wave generation circuit.

4) By using the transmission / reception frequency conversion circuit, the circuit having the same function in the device is shared, and the circuit can be simplified, downsized, and reduced in cost. And so on, an extremely excellent effect can be expected.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a third embodiment of the present invention.

FIG. 4 is a block diagram of a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a fifth embodiment of the present invention.

FIG. 6 is a block diagram of a sixth embodiment of the present invention.

FIG. 7A is a block diagram of a seventh embodiment of the present invention, and FIGS. 7B to 7E are drawings showing an example of an M-times multiplier.

FIG. 8 is a block diagram of an eighth embodiment of the present invention.

FIG. 9A is a block diagram of a ninth embodiment,
(B) is a block diagram of an M times circuit for frequency N.

FIG. 10 is a transmission I used in the tenth embodiment of the present invention.
It is a block diagram of an F sine wave generation circuit.

11A and 11B are block diagrams of a reception frequency conversion circuit and a transmission frequency conversion circuit, respectively.

FIG. 12 is a block diagram of a frequency conversion circuit using a transmission / reception mixer.

FIG. 13 is a block diagram of a frequency conversion circuit using a bidirectional mixer.

FIG. 14 is a block diagram of an eleventh embodiment of the present invention.

FIG. 15 is a block diagram of a twelfth embodiment of the present invention.

FIG. 16 is a block diagram of a conventional transmission / reception device.

FIG. 17 is a block diagram of a conventional example.

FIG. 18 is a block diagram of a conventional example.

FIG. 19 is a block diagram of a conventional example.

[Explanation of symbols]

 1 Reference signal source 2 Phase-locked circuit 3 VCO 4 Transmission / reception phase-locked oscillator circuit 5 Reception frequency conversion circuit 6 Transmission frequency conversion circuit 7 Transmission IF sine wave generation circuit 8 Demodulator 9 IF modulation circuit 10 Transmission terminal 11 Reception terminal 12 RF modulation 13 Direct phase-locked modulation circuit 14 Waveform shaping circuit 15 Adder 16 Up-converter 17 Down-converter 18 Local phase-locked oscillator circuit 19 Transmission / reception switch 23 Control terminal 24 Digital signal processing circuit 25 Reference clock 26 Transmission IF sine wave generation circuit 30 Frequency M times circuit 41 Frequency 1 / N circuit 73 Transmission / reception mixer 82 Bidirectional mixer

Claims (6)

[Claims] 1. A at least one reference signal source having the same transmission / reception frequency and provided in any part of the device, and a demodulator for demodulating a reception IF frequency signal having a modulated VHF band or less. , The difference between the oscillation frequency and the reception frequency is the reception IF frequency, and the reception signal and the transmission / reception oscillation circuit output are input to the demodulator.
A reception frequency conversion circuit that outputs an F signal, a transmission IF frequency generation circuit, and a transmission IF frequency signal that has the same frequency as the reception IF frequency or a signal that is output from the oscillation circuit for both transmission and reception is modulated by transmission information. A modulator,
A transmitter / receiver comprising a transmission frequency conversion circuit which outputs a transmission signal when the modulator output signal and a transmission IF frequency signal or a signal from the transmission / reception / oscillation circuit, which is the other unmodulated signal, is inputted. The received signal and the output signal of the oscillation circuit for both transmission and reception are input to the frequency conversion circuit, the received IF signal that is the output is input to the demodulator to obtain the reception information, and at the time of transmission, the output of the oscillation circuit for both transmission and reception is transmitted by the modulator according to the transmission information. Or the signal of the transmission IF frequency is modulated, and the modulated signal is input to the transmission frequency conversion circuit together with the other unmodulated signal to obtain the transmission signal. The transmission IF frequency generation circuit outputs the signal of the transmission IF frequency required for transmission to at least one reference signal source output provided in the device. Transmitting and receiving apparatus and generates by use. 2. The transmission / reception according to claim 1, wherein a signal having a transmission IF frequency is output only during transmission, and a signal having a transmission IF frequency component equal to the reception IF frequency component is not output within the device during reception. apparatus. 3. The relationship between the IF transmission frequency f _ITX and an arbitrary reference signal source frequency f _{r in} any part of the apparatus is _{expressed by} the following equation: In addition, as the transmission IF frequency signal generating means, a frequency M times circuit that is in an output state only at the time of transmission is used, the reference signal source output is input to the frequency M times circuit, and the transmission IF frequency signal is transmitted only at the time of transmission. The transmission / reception device according to claim 1, wherein the transmission / reception device is generated. 4. The relationship between the transmission IF frequency f _ITX and the reference signal source frequency f _r in any part of the apparatus is _{expressed by} the following equation: Further, as the transmission IF frequency signal generating means, a frequency 1 / N circuit that is in an output state only during transmission is used, and the reference signal source output is input to the frequency 1 / N circuit to transmit only during transmission. The transmitter / receiver according to claim 1 or 2, which generates an IF frequency signal. 5. The relationship between the transmission IF frequency f _ITX and an arbitrary reference signal source frequency f _{r in} any part of the device is _{expressed by} the following equation: In addition, as the transmission IF frequency signal generation means, an M-fold circuit for a frequency N that is in an output state only during transmission is used,
3. The transmitter / receiver according to claim 1, wherein a transmission IF signal is generated only during transmission by inputting the output of the arbitrary reference signal source to the M-fold circuit for the frequency N. 6. A transmission IF frequency f _ITX and an oscillation frequency f of k reference signal sources among a plurality of reference signal sources in the apparatus.
The relation of _rj (j = 1 to k) is as follows: Further, the transmission IF frequency signal generation means outputs k frequencies M _j / N _j multiplication circuits and k inputs for outputting the sum or difference of these k M _j / N _j multiplication circuit output signal frequencies. One output frequency mixing circuit is included, and an arbitrary number of reference signal source outputs are input to the corresponding M _j / N _j times circuits, and the outputs are mixed to generate a transmission IF frequency signal only during transmission. The transmitter / receiver according to claim 1 or 2.