JP2939418B2 - Transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception apparatus for giving a measurement error when an angle tracking radar such as a monopulse radar of the other party performs an angle measurement.

[0002]

2. Description of the Related Art FIG. 11 shows, for example, LEROY B. VAN BRUNT.
By APPLIED ECM (EW ENGINEERING INC. 1978, pp.55
6-572) is a functional block diagram of this type of transmitting and receiving apparatus, wherein 1 and 2 are receiving antennas for receiving transmission radio waves of a radar apparatus on the other side that causes an error,
3 and 4 are transmission antennas for transmitting radio waves to the other party's radar device, 5 is a phase shifter for adjusting the phase between the signal transmitted from the transmission antenna 3 and the signal transmitted from the transmission antenna 4, Reference numeral 6 denotes a 180 ° phase converter for inverting the phase of a signal received by the receiving antenna 2, reference numeral 7 denotes an amplifier that amplifies the output of the phase shifter 5 and outputs the output to the transmitting antenna 4, and reference numeral 8 denotes 1
This is an amplifier that amplifies the output of the 80 ° phase converter 6 and outputs it to the transmitting antenna 3.

Next, the operation will be described. This transmission / reception device is called a cross eye, and is mounted on, for example, an aircraft.
This transceiver receives a transmission signal from an angle tracking radar such as a monopulse radar installed on the ground or mounted on a flying object, inverts its phase by 180 °, amplifies it to equal amplitude, and Send to

[0004] A receiving antenna 1 installed near a transmitting antenna 3 receives a radio wave from a radar. This received signal is input to the phase shifter 5, where a predetermined phase adjustment is performed. The output of the phase shifter 5 is input to the amplifier 7, where it is amplified and then output to the transmitting antenna 4. The transmitting antenna 4 transmits the amplified received signal. On the other hand, the receiving antenna 2 installed near the transmitting antenna 4 also receives radio waves from the radar. This received signal is input to the 180 ° phase converter 6, where the phase is shifted (inverted) by 180 °. The output of the 180 ° phase converter 6 is input to the amplifier 8, where it is amplified to the same amplitude as the output of the amplifier 7 and then output to the transmitting antenna 3. Transmission antenna 3
Transmits the amplified received signal.

When the transmitting / receiving apparatus shown in FIG. 11 operates in this manner, the angle tracking radar such as a monopulse radar, in addition to the original received signal reflected by the aircraft body, receives the amplified signal from the transmitting antenna 4 and the transmitting antenna. Since the amplified signals whose phases are shifted from each other by 180 ° (these signals have the same amplitude) are simultaneously received, a normal angle measurement is not performed, and an error occurs in the angle measured for the aircraft.

[0006]

A conventional transmitting / receiving apparatus is:
With the configuration described above, it is difficult to secure isolation because the receiving operation and the transmitting operation are performed simultaneously. If the isolation cannot be ensured, the transmission radio wave transmitted by itself will be received by its own receiving antenna, processed, and transmitted again.Therefore, a closed loop of the processing will be formed, and an oscillation state may occur. The phase difference could not be secured and the interference performance was sometimes reduced. In addition, the phase may change due to various causes, and it may not be possible to provide effective interference to the other party's radar.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide a transmitting / receiving apparatus that does not lower the interference performance.

[0008]

According to a first aspect of the present invention, there is provided a transmission / reception apparatus in which a distance between a first reception antenna and a first transmission antenna and a distance between a second reception antenna and a second transmission antenna are all set. long, and the target and the sum of distances and the distance between the target and the first transmitting antenna of the first reception antenna, the distance and the target and the second between the target and the second receiving antenna And the sum of the distances to the transmission antennas of the second amplifier is equalized .
The first receiving antenna is output from the second transmitting antenna based on the output.
A pseudo signal generation circuit for simulating a signal
The output signal of the pseudo signal generating circuit is supplied to the first receiving antenna.
And a subtractor for subtracting from the output signal of

[0009]

According to a second aspect of the present invention, there is provided a transmission / reception apparatus for determining a phase difference between an output signal of a first amplifier and an output signal of a second amplifier, and comparing the phase difference with a predetermined phase difference. A phase shifter for adjusting the phase of the output signal of the first receiving antenna based on the output of the comparator.

According to a third aspect of the present invention, there is provided a transmission / reception device including a phase variable device for changing a phase of an output signal of the second receiving antenna in a predetermined range, instead of the phase converter.

According to a fourth aspect of the present invention, a first frequency converter for converting an output signal of the second receiving antenna into a low-frequency signal and a second frequency converter for converting an output signal of the phase converter into a high-frequency signal. A frequency converter, wherein the phase converter converts a phase at a low frequency.

According to a fifth aspect of the present invention, there is provided a transmitting / receiving apparatus comprising: a first delay line for delaying an output signal of a first receiving antenna;
And a second delay line for delaying the output signal of the receiving antenna.

According to a sixth aspect of the present invention, there is provided a transmitting / receiving apparatus, wherein the delay time of the first delay line and the delay time of the second delay line are set as follows:
This is the same as the pulse width of the radio wave transmitted by the target.

[0015]

According to the first aspect of the present invention, the first receiving antenna and the first transmitting antenna, and the second receiving antenna and the second transmitting antenna are spaced apart from each other, so that mutual coupling is reduced. In addition, the sum of the distance between the target and the first receiving antenna and the distance between the target and the first transmitting antenna, the distance between the target and the second receiving antenna, the target and the second By arranging them so that the total distance from the transmitting antenna is equal, the line length in space becomes the same. Also, a pseudo signal generation circuit
From the second transmitting antenna based on the output of the second amplifier
Pseudo signal simulating a signal wrapping around the first receiving antenna
And the subtractor outputs the output signal of the pseudo signal generation circuit.
Subtraction is performed from the output signal of the first receiving antenna.

[0016]

According to a second aspect of the present invention, the phase comparator determines the phase difference between the output signal of the first amplifier and the output signal of the second amplifier, compares the phase difference with a predetermined phase difference, Adjusts the phase of the output signal of the first receiving antenna such that the phase difference becomes a predetermined phase difference based on the output of the phase comparator.

According to the third aspect of the present invention, the phase variable device changes the phase of the output signal of the second receiving antenna within a predetermined range.

According to a fourth aspect of the present invention, the first frequency converter converts the output signal of the second receiving antenna into a low frequency signal, and the second frequency converter converts the output signal of the phase converter. The signal is converted into a high-frequency signal, and the phase converter converts the phase at a low frequency.

According to the fifth aspect of the present invention, the first delay line delays the output signal of the first receiving antenna, and the second delay line delays the output signal of the second receiving antenna to reduce the transmission period. Make sure that the reception period does not match.

In the invention of claim 6 , the first delay line and the second delay line delay the reception signal by the same time as the pulse width of the radio wave transmitted from the target.

[0022]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a functional block diagram of the transmission / reception device according to the first embodiment. In the drawing, reference numerals 1 and 2 denote receiving antennas for receiving radio waves transmitted from a radar apparatus on the partner side that causes an error, reference numerals 3 and 4 denote transmitting antennas for transmitting radio waves to the radar apparatus on the partner side, and 6 denotes a receiving antenna A phase converter for inverting the phase of the signal received at step 180, an amplifier 7 for amplifying the output of the loop interference wave removing circuit 17 and outputting it to the transmitting antenna 4, and an amplifier 8 for amplifying the output of the 180 ° phase converter and transmitting the amplified signal An amplifier for outputting to the antenna 3, 9 and 11 are receiving units for receiving and processing radio waves received by the receiving antennas 1 and 2, and 10 and 12 are a receiving unit for receiving and processing a part of outputs of the amplifiers 8 and 7, respectively. 16 to 16 are A / D converters for converting the outputs of the receiving units 9 to 12 from analog signals to digital signals, respectively, and 17 is the A / D converter 1
A wraparound wave elimination circuit that removes a radio wave that wraps around from a transmission antenna to a reception antenna based on the outputs of 3 and 14, 18 is a wraparound wave elimination circuit that processes the output of the A / D converters 15 and 16, and 19 is a wraparound wave elimination circuit. 17 which converts the digital output of D.17 into an analog signal and outputs it to the amplifier 7
A / A converter 20 converts a digital output of the 180 ° phase converter 6 into an analog signal and outputs the analog signal to the amplifier 8.
The converters 21 and 22 are directional couplers that take out a part of the outputs of the amplifiers 8 and 7 and output them to the receiving units 10 and 12, respectively.

FIG. 2 is a diagram showing the arrangement of the receiving antennas 1 and 2 and the transmitting antennas 3 and 4. In the figure,
P indicates the position of the antenna of the other radar device. Also,
a, d, c, and b represent the position P of the other radar device, respectively.
And the distance between the receiving antennas 1 and 2 and the transmitting antennas 3 and 4.

FIG. 3 is a circuit diagram of the loop interference wave removing circuit 1 shown in FIG.
It is an internal block diagram of 7 and 18, and in FIG.
1a to 101c are delay circuits for delaying a transmission signal;
2a to 102d are coefficient multipliers for multiplying the transmission signal and the delayed transmission signal by predetermined coefficients, 103 is a synthesizer for synthesizing the outputs of the coefficient multipliers 102a to 102d, 10
Reference numeral 4 denotes a subtractor for subtracting the output of the synthesizer 103 from the received signal.

Next, the operation will be described. The receiving antenna 1 installed near the transmitting antenna 3 receives a radio wave from the other party's radar. This reception signal is converted into a signal of a predetermined frequency by the reception unit 9 and then the A / D converter 1
3 to be converted into a digital signal. A / D converter 13
Is input to the D / A converter 19 after the wraparound wave signal is removed to some extent by the wraparound wave removal circuit 17. The operation of the loop wave removing circuit 17 will be described later. The output of the loop echo removal circuit 17 is D /
After being converted into an analog signal by the A converter 19, the analog signal is input to the amplifier 7, where it is amplified and then the directional coupler 2
The signal is output to the transmission antenna 4 through the transmission antenna 2. The transmitting antenna 4 transmits the amplified received signal.

On the other hand, the receiving antenna 2 installed near the transmitting antenna 4 also receives radio waves from the radar. The received signal is converted into a signal of a predetermined frequency by the receiving unit 11 and then converted to a digital signal by the A / D converter 15. The output signal of the A / D converter 15 is input to the 180 ° phase converter 6 after the wraparound wave signal has been removed to some extent by the wraparound wave removal circuit 18, where the phase is shifted (inverted) by 180 °. 180 ° phase converter 6
Is converted into an analog signal by the D / A converter 20 and then input to the amplifier 8, where it is amplified and then output to the transmitting antenna 3 via the directional coupler 21. The transmitting antenna 3 transmits the amplified received signal.

The transmitting and receiving apparatus according to the first embodiment is characterized in that the arrangement of the receiving antennas 1 and 2 and the transmitting antennas 3 and 4 is as shown in FIG. 2 in order to ensure isolation between the received signal and the transmitted signal. , And the loop wave removal circuit 17,
18 is provided. Next, these will be described.

First, the arrangement of the receiving antennas 1 and 2 and the transmitting antennas 3 and 4 will be described. The longer the distance between the receiving antenna and the transmitting antenna, the smaller the coupling between them. To ensure isolation, the distance between the receiving antenna 1 and the transmitting antenna 4, the distance between the receiving antenna 2 and the transmitting antenna 3, What is necessary is just to make each distance long. However, in order for the transmitting / receiving device using this cross eye to exhibit its performance, a certain distance between the transmitting antenna 3 and the transmitting antenna 4 is required in terms of the operation principle. Further, the sum of the distance between the other party's radar (P in FIG. 2) and the receiving antenna 1 (a in FIG. 2), the distance between the other party's radar and the transmitting antenna 4 (b in FIG. 2), and the other party's radar and reception The sum of the distance to the antenna 2 (d in FIG. 2) and the distance between the other party's radar and the transmitting antenna 3 (c in FIG. 2) must be equal.
That is, a + b = c + d must be satisfied. If this condition cannot be satisfied, the receiving antenna 1 and the transmitting antenna 4
A difference occurs in the line length of the free space between the signal of the system due to the above and the signal of the system due to the receiving antenna 2 and the transmitting antenna 3, so that the phase difference of the signal received by the radar of the other party is maintained at a predetermined value. It is not possible.

An example of an arrangement satisfying these conditions is the arrangement shown in FIG. That is, the receiving antenna 1 and the transmitting antenna 3 and the receiving antenna 2 and the transmitting antenna 4 are
The antennas are arranged close to each other, and the corresponding transmitting antennas and receiving antennas are symmetrical with respect to the intermediate point between the receiving antenna 1, the transmitting antenna 3 and the receiving antenna 2, and the transmitting antenna 4. Further, the distance between the set of the receiving antenna 1 and the transmitting antenna 3 and the set of the receiving antenna 2 and the transmitting antenna 4 is increased. According to this arrangement, the distance between the corresponding transmitting antenna and the receiving antenna is increased, and isolation can be achieved. In addition, the distance between the transmitting antennas is increased, and the condition of the line length is satisfied. There is no performance degradation.

Next, the operation of the loop interference wave removing circuits 17 and 18 will be described with reference to FIGS. The principle of operation of the loop interference wave removing circuits 17 and 18 is to determine in advance how much the loop interference wave is generated in the received signal by calculation or experiment, generate the same signal as the loop interference wave based on the transmission signal, and receive it. It is intended to remove only the looping-in wave by subtracting it from the signal.

In FIG. 1, the output signal of the amplifier 8 is radiated to the space by the transmitting antenna 3, but the directional coupler 2
A part is taken out by 1 and input to the receiving unit 10. The output signal of the receiving unit 10 is converted into a digital signal by the A / D converter 14 and then turned around.
Is input as a transmission signal. This transmission signal is sequentially delayed by a predetermined time by the delay circuits 101a to 101c. Then, the coefficient multipliers 102a to 102d multiply the transmission signal, the output of the delay circuit 101a, the output of the delay circuit 101b, and the output of the delay circuit 101c by predetermined coefficients. Note that the delay time and the coefficient are determined in advance by calculation or the like based on the actual arrangement of the receiving antenna and the transmitting antenna (for example, the arrangement in FIG. 2) so that the amount of wraparound from the transmitting antenna to the receiving antenna can be calculated.

The synthesizer 103 is provided with the coefficient multiplier 102
By combining the outputs of a to 102d, a pseudo signal of a loop wave superimposed on the received signal is generated. These delay circuits, coefficient multipliers, and combiners simulate a transfer function of a loop from a transmitting antenna to a receiving antenna. Then, the subtractor 104 converts the received signal
3 subtracts the pseudo signal of the wraparound wave and outputs the result to the D / A converter 19 as a reception wave after the wraparound wave removal. The operation of the loop interference wave removing circuit 18 is the same. As described above, since the pseudo signal of the wraparound wave is removed from the received signal, if the pseudo signal of the wraparound wave output from the combiner 103 is the same as the actual wraparound wave signal, the reception signal from the other party's radar is affected. Can be eliminated without giving the following. Although the delay circuit 101 has three stages in FIG. 3, the present invention is not limited to this, and a configuration having four or more stages may be employed.

When the transmitting / receiving apparatus of FIG. 1 operates as described above, the angle tracking radar such as the monopulse radar transmits the amplified signal from the transmitting antenna 4 and the transmitted signal in addition to the original received signal reflected by the aircraft body. Since an amplified signal whose phase is shifted by 180 ° from the antenna 3 is received at the same time, a normal angle measurement is not performed, and an error occurs in the angle measured for the aircraft.

This will be described in detail. A tracking radar that fixedly tracks a target in a one-to-one manner, such as a monopulse method or a conical scan method, operates so as to directly face a phase wavefront of a radio wave reflected by the target and tracks the target.
When a radar having such characteristics undergoes cross-eye jamming using two sources having different phases, a phase wavefront is distorted due to an interference phenomenon due to the jamming, and thus an angle tracking error increases. The value of the angle error is determined by the interval between the two transmitting antennas, and the phase difference and the amplitude ratio of radio waves radiated from the two transmitting antennas. The angle error increases as the interval between the transmitting antennas increases, and the angle error increases as the phase difference becomes 180 ° and the amplitude ratio approaches 1.

In the transmitting / receiving apparatus shown in FIG. 1, the receiving antenna and the transmitting antenna are arranged as shown in FIG.
Since the loop echo removal circuits 17 and 18 are provided, isolation can be ensured.

As described above, according to the transmission / reception device of the first embodiment, sufficient isolation can be ensured, and a stable operation can be performed without forming a closed loop of processing. Interference performance is improved.

Since the transmission / reception apparatus shown in FIG. 1 performs processing in a digital system, accurate and stable processing can be performed as compared with the case of the analog system, and the phase difference can be accurately and stably maintained at a predetermined value. Performance is improved.

Further, in the first embodiment, the combination of the arrangement of the transmitting antenna and the receiving antenna capable of achieving isolation and the loop interference wave removing circuit enables
Although high isolation is realized, it goes without saying that the isolation is improved by using only one of them, that is, only one of the arrangement of the transmitting antenna and the receiving antenna or one of the loop interference wave removing circuits.

Embodiment 2 FIG. In the first embodiment, the phase of the output signal of the loop interference wave removing circuit 17 is not adjusted. However, by providing a phase shifter capable of changing the amount of phase,
This may be automatically adjusted.

FIG. 4 is a functional block diagram of the transmitting / receiving apparatus according to the second embodiment. In FIG. 4, reference numeral 30 denotes a phase of a signal transmitted from the transmitting antenna 3 and a phase of a signal transmitted from the transmitting antenna 4. A phase comparator for comparing and calculating a phase difference therebetween, 31 is a phase shifter for adjusting a phase shift amount of a signal received by the receiving antenna 1 based on an output signal of the phase comparator 30, and 32 is a transmitting antenna for outputting an output of the amplifier 8 3 and a part thereof is received by the receiving unit 10 and the phase comparator 30.
A directional coupler 33 supplies the output of the amplifier 7 to the transmitting antenna 4 and distributes a part of the output to the receiving unit 12 and the phase comparator 30.

The receiving antennas 1 and 2, the transmitting antennas 3, 4, and the 180 ° phase converter 6, the amplifiers 7, 8, the receiving units 9 to 12, the A / D converters 13 to 16, the wraparound wave removing circuit 17, 18. The D / A converters 19 and 20 are the same as those shown in FIG.

Next, the operation will be described. In this type of transmission / reception apparatus, it is important to provide isolation between transmission and reception. However, in order to cause angle deception on the other radar, it is necessary to exactly reverse the phase by 180 °. Phase comparator 3 in the second embodiment
0 and the phase shifter 31 are for maintaining the phase difference accurately. That is, the phase comparator 30 compares the radio wave output from the transmission antenna 3 with the radio wave output from the transmission antenna 4 and obtains a phase difference therebetween. This phase difference is 1
When the angle is 80 °, the transmitting and receiving apparatus of the second embodiment exhibits the best performance. Therefore, the phase comparator 30 adjusts the phase shift amount of the phase shifter 31 so as to maintain the phase difference at 180 °.

As described above, according to the second embodiment, the transmitting antenna and the receiving antenna are arranged so as to be isolated from each other, and the loop antenna removing circuit is provided.
Furthermore, since a phase comparator and a phase shifter controlled by the phase comparator are provided, a predetermined phase difference is maintained between transmission signals even when a line length changes due to a temperature change or the like and a phase difference changes. However, the performance of the transmitting / receiving device does not deteriorate.

Embodiment 3 FIG. In the second embodiment, the transmitting and receiving apparatus in which the predetermined phase difference is maintained by controlling the phase error based on the comparison result of the transmission signal to reduce the phase error has been described. May be changed.

FIG. 5 shows a functional block diagram of the transmitting / receiving apparatus according to the third embodiment. In the figure, reference numeral 34 denotes a phase variable device that changes the phase of a signal received by the receiving antenna 2.
The receiving antennas 1 and 2, the transmitting antennas 3 and 4, the amplifiers 7 and 8, the receiving units 9 to 12, the A / D converters 13 to 16,
Sneak wave removing circuits 17, 18, D / A converters 19, 2,
0, the directional couplers 21 and 22 are the same as those shown in FIG.

Next, the operation will be described. Example 2 above
In the above, the phase difference was adjusted, and the phase was exactly inverted by 180 °. However, when the phase adjustment cannot be performed accurately due to a temperature change or the like, or when the accurate phase adjustment is not performed,
Interference effects may not be obtained. Therefore, in the third embodiment, a point where the phase difference is 180 ° is stochastically obtained by arbitrarily changing the phase difference within a predetermined range.

That is, the phase variable unit 34 provided in place of the 180 ° phase converter of FIG. 1 changes the phase of the received signal of the receiving antenna 2 to, for example, 170 ° to 1 ° as shown in FIG.
Change between 90 °. FIG. 6 shows a case where the phase shift amount is linearly changed from 180 ° → 190 ° → 170 ° → 190 ° in a constant cycle. As described above, by changing the phase under the predetermined condition, the possibility that the interference effect cannot be obtained can be reduced.

As described above, according to the third embodiment, the transmitting antenna and the receiving antenna are arranged so as to be able to be isolated, and a loop interference wave removing circuit is provided.
In addition, since a phase ratio variable device that changes the phase is provided, even if the line length changes due to a temperature change, etc., and the phase difference changes, a point where the phase difference is 180 ° is obtained stochastically, and The possibility that the effect cannot be obtained can be reduced. According to the third embodiment, the phase shifter and the 180 ° phase converter required in the first and second embodiments become unnecessary.

Embodiment 4 FIG. In the first to third embodiments, the transmission / reception device that converts a received signal into a digital signal and then processes the digital signal is described. It may be.

FIG. 7 shows a functional block diagram of the transmitting / receiving apparatus according to the fourth embodiment. In the figure, 5 is a phase shifter for adjusting a phase difference between a signal transmitted from the transmitting antenna 3 and a signal transmitted from the transmitting antenna 4, 25 is a local oscillator for generating a local signal, and 26 and 28 are local oscillators. Frequency converters for converting a high-frequency signal to a low-frequency signal based on the output of the oscillator 25, and frequency converters 27 and 29 for converting a low-frequency signal to a high-frequency signal based on the output of the local oscillator 25. The receiving antennas 1 and 2, the transmitting antennas 3 and 4, and the amplifiers 7 and 8 are the same as those shown in FIG. Also, 1
The 80 ° phase converter 6 is the same as that shown in FIG. 1 except that it operates in analog.

Next, the operation will be described. Example 4
Operates in the same manner as in the first embodiment except that it operates in analog and does not remove the loop interference wave. According to the fourth embodiment, since the processing of the phase of the received signal is performed after the frequency is converted to a low frequency, the influence of the error in the transmission line length can be reduced and the phase adjustment can be easily performed.

For example, when the frequency of the received signal is 1 GHz, the wavelength is λ ′ = 210 mm when the wavelength shortening rate by the line is 70%. At this time, the transmission line length is 6m
If an error of m occurs, the phase is shifted by 10 °, and the interference performance is greatly reduced. However, if the frequency is converted to 100 MHz by the frequency converters 26 and 28, the wavelength is reduced to one tenth, so that the wavelength is shifted by only 1 °, and the interference performance is not significantly reduced. Also, when the phase is adjusted, fine adjustment can be performed with the same transmission line length, so that the adjustment becomes easy. After predetermined phase processing is performed at a low frequency, the signal is again converted to a high frequency signal by the frequency converters 27 and 29, amplified, and radiated from the transmission antennas 3 and 4 to the outside.

As described above, according to the fourth embodiment, the processing of the phase of the received signal is performed after the phase is converted to a low frequency.
The influence of the error in the transmission line length can be reduced, the phase can be easily adjusted, and the interference performance is improved.

Although the transmission / reception apparatus shown in FIG. 7 does not include the loop interference wave removing circuit, it may have a configuration including the loop interference wave removing circuit as shown in FIG. In this case, the operation is the same except that the processing is performed with an analog signal. The antennas 1 to 4 may be arranged as shown in FIG.

Embodiment 5 FIG. In the first embodiment, the transmission / reception device that removes the wraparound wave using the wraparound wave removal circuit is described. However, the present invention is not limited to this, and the wraparound wave may be removed by a time division method. FIG. 8 shows the fifth embodiment.
1 is a functional block diagram of a transmitting / receiving device of FIG. In the figure,
23 and 24 are delay lines for respectively delaying the signals received by the receiving antennas 1 and 2 by a delay time in consideration of the pulse width of the other party's radar. The receiving antennas 1, 2, the transmitting antennas 3, 4, the phase shifter 5, the 180 ° phase converter 6,
The amplifiers 7 and 8 are the same as those shown in FIG.

Next, the operation will be described. Example 5
In this method, transmission is performed after a certain delay time so that reception and transmission are not performed simultaneously, thereby ensuring isolation between transmission and reception. For example, as shown in the timing chart of FIG. 4, reception processing is first performed by the reception antennas 1 and 2, and then transmission is performed from the transmission antennas 3 and 4 after a predetermined time has elapsed by the processing of the delay lines 23 and 24. Then, this operation is repeated. Since the transmission and the reception are not performed simultaneously by alternately repeating the transmission and the reception in this manner, the wraparound is reduced.

If the delay time of the delay lines 23 and 24 is too long, the signal received by the other party's radar will be separated from the signal reflected by the aircraft equipped with the transceiver and the signal transmitted by the transceiver. Decrease. Therefore, as shown in FIG. 10, the delay time t _d of the delay lines 23 and 24 is set to the pulse width τ of the transmission pulse of the partner radar.
(T _d = τ). When the pulse width τ changes, the delay time changes accordingly. By setting the delay time in this manner, isolation can be ensured without reducing the effect of interference.

As described above, according to the transmitting / receiving apparatus of the fifth embodiment, sufficient isolation can be ensured, and a stable operation can be performed without forming a closed loop of processing. Interference performance is improved.

In the fifth embodiment, a combination of the arrangement of the transmitting antenna and the receiving antenna capable of achieving isolation and the loop interference wave removing circuit as in the first embodiment may be applied. , Higher isolation can be realized.

[0060]

As described above, according to the first aspect of the present invention, the distance between the first receiving antenna and the first transmitting antenna and the distance between the second receiving antenna and the second transmitting antenna are determined. And the sum of the distance between the target and the first receiving antenna and the distance between the target and the first transmitting antenna, the distance between the target and the second receiving antenna, the target and the Since the antennas are arranged so that the total distance from the second transmitting antenna is equal, isolation can be ensured, operation is stabilized, and performance degradation of the transmitting / receiving apparatus can be prevented. Also, the output of the second amplifier
A second transmitting antenna to a first receiving antenna based on force
A pseudo-signal generation circuit that simulates a signal
The output signal of the similar signal generation circuit is output from the first receiving antenna.
A subtractor for subtracting from the output signal is provided.
Isolation can be increased.

[0061]

According to the second aspect of the present invention, there is provided a phase comparator for determining the phase difference between the output signal of the first amplifier and the output signal of the second amplifier, and comparing the phase difference with a predetermined phase difference.
A phase shifter that adjusts the phase of the output signal of the first receiving antenna based on the output of the phase comparator, so that even if the line length changes and the phase difference changes, the transmission signal , The predetermined phase difference is maintained, and the performance of the transmitting / receiving apparatus can be prevented from deteriorating.

According to the third aspect of the present invention, a phase changer for changing the phase of the output signal of the second receiving antenna within a predetermined range is provided instead of the phase converter. Even when the phase difference changes due to the change in the line length, the operation can be performed stochastically with an effective phase difference, and the performance of the transmission / reception device can be prevented from lowering.

According to the fourth aspect of the present invention, the first frequency converter for converting the output signal of the second receiving antenna into a low frequency signal, and the first frequency converter for converting the output signal of the phase converter into a high frequency signal. Since the above-mentioned phase converter converts the phase at a low frequency, the influence of an error in the transmission line length can be reduced, and the performance of the transmission / reception device can be prevented from deteriorating.

According to the fifth aspect of the present invention, the first delay line for delaying the output signal of the first receiving antenna and the second delay line for delaying the output signal of the second receiving antenna are provided. With this configuration, isolation can be ensured with a simple configuration, and a decrease in the performance of the transmission / reception device can be prevented.

According to the sixth aspect of the present invention, the first type
Since the delay time of the delay line and the delay time of the second delay line are set to be equal to the pulse width of the radio wave transmitted by the target, isolation can be secured without deteriorating the function.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a transmission / reception device according to a first embodiment of the present invention.

FIG. 2 is an arrangement diagram of an antenna of the transmission / reception device according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram of a loop interference wave removing circuit of the transmitting and receiving apparatus according to the first embodiment of the present invention.

FIG. 4 is a functional block diagram of a transmission / reception device according to a second embodiment of the present invention.

FIG. 5 is a functional block diagram of a transmission / reception device according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of an operation of the phase changer of the transmission / reception device according to the third embodiment of the present invention.

FIG. 7 is a functional block diagram of a transmission / reception device according to a fourth embodiment of the present invention.

FIG. 8 is a functional block diagram of a transmitting / receiving apparatus according to Embodiment 5 of the present invention.

FIG. 9 is an operation timing chart of the transmission / reception apparatus according to Embodiment 5 of the present invention.

FIG. 10 is an explanatory diagram of a relationship between a delay time t _d and a pulse width τ of a received pulse.

FIG. 11 is a functional block diagram of a conventional transmitting / receiving apparatus.

[Explanation of symbols]

1, 2 receiving antenna, 3, 4 transmitting antenna, 5 phase shifter, 6 180 ° phase converter, 7, 8 amplifier, 9 ~
12 receiver, 13-16 A / D converter, 17, 18
Lingering wave removal circuit, 19, 20 D / A converter 1,
21, 22 directional coupler, 23, 24 delay line, 25
Local oscillator, 26-29 frequency converter, 30 phase comparator, 31 phase shifter, 32, 33 directional coupler, 3
4 Phase changer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 7/38 G01S 13/44 G01S 13/87

Claims (6)

(57) [Claims] 1. A first receiving antenna for receiving a radio wave transmitted from a target, a first amplifier for amplifying an output signal of the first receiving antenna, and a radio wave receiving an output signal of the first amplifier. A first transmitting antenna for transmitting a signal, a second receiving antenna for receiving a radio wave transmitted by the target, a phase converter for converting the phase of an output signal of the second receiving antenna, A transmission / reception apparatus comprising: a second amplifier that amplifies an output signal; and a second transmission antenna that receives an output signal of the second amplifier and transmits a radio wave, wherein the first reception antenna and the first transmission both the distance and the distance between the second receiving antenna and said second transmit antennas of the antenna longer, and the distance and the target of the target and the first receiving antenna first transmit antenna Distance Sum of, the sum of distances and the distance between the target and the second transmission antennas of the target and the second receiving antenna is arranged to equalize the output of the second amplifier Based on the second transmission antenna
To simulate the signal sneaking from the antenna to the first receiving antenna.
Pseudo signal generation circuit, and the output signal of the above pseudo signal generation circuit.
Signal from the output signal of the first receiving antenna.
A transmission / reception device comprising a calculator . 2. An output signal of said first amplifier and said second amplifier.
A phase comparator for obtaining a phase difference from the output signal of the amplifier of the first embodiment and comparing the phase difference with a predetermined phase difference; and a phase shifter for adjusting the phase of the output signal of the first receiving antenna based on the output of the phase comparator The transmission / reception device according to claim 1, further comprising a transmitter. 3. The apparatus according to claim 1, further comprising a phase changer that changes the phase of the output signal of the second receiving antenna within a predetermined range, instead of the phase converter.
The transmitting / receiving device as described in the above. 4. A first frequency converter for converting an output signal of the second receiving antenna into a low-frequency signal, and a second frequency converter for converting an output signal of the phase converter into a high-frequency signal. 2. The transmission / reception apparatus according to claim 1, wherein the phase converter converts a phase at a low frequency. 5. A first receiving antenna for receiving a radio wave transmitted from a target, a first amplifier for amplifying an output signal of the first receiving antenna, and a radio wave receiving the output signal of the first amplifier. A first transmitting antenna for transmitting a signal, a second receiving antenna for receiving a radio wave transmitted by the target, a phase converter for converting the phase of an output signal of the second receiving antenna, A transmission / reception device including a second amplifier that amplifies an output signal and a second transmission antenna that receives an output signal of the second amplifier and transmits a radio wave, wherein an output signal of the first reception antenna is delayed. A transmission / reception apparatus comprising: a first delay line; and a second delay line for delaying an output signal of the second reception antenna. 6. The transmission / reception according to claim 5, wherein the delay time of the first delay line and the delay time of the second delay line are the same as the pulse width of the radio wave transmitted by the target. apparatus.