JPH0843521A - Transmitter-receiver - Google Patents

Abstract

PURPOSE:To obtain a transmitter-receiver which ensures an isolation between a receiving antenna and a transmitting antenna and which prevents a drop in performance. CONSTITUTION:The transmitter-receiver is provided with two sets of receiving antennas and transmitting antennas which receive radio waves sent by a radar and which again transmit signals whose phase is shifted from each other by 180 deg.. Then, an error is generated in the angle of measurement of a partner radar. The receiving antennas 1, 2 and the transmitting antennas 3, 4 are arranged in such a way that their mutual distance is long and that a difference is not generated in a line length up to a target. In addition, the transmitter- receiver is provided with sneaked-wave removal circuits 17, 18 in which a signal sneaked into the receiving antennas 1, 2 from the transmitting antennas 3, 4 is simulated and which subtract the simulated signal from a received signal so as to remove sneaked waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter / receiver for giving a measurement error when an angle tracking radar such as a counterpart monopulse radar or the like measures an angle.

[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 / receiving device, in which 1 and 2 are reception antennas for receiving the transmission radio waves of the radar device on the other side causing an error,
3 and 4 are transmission antennas for transmitting radio waves to the radar device on the other side, 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, 6 is a 180 ° phase converter for inverting the phase of the signal received by the receiving antenna 2, 7 is an amplifier for amplifying the output of the phase shifter 5 and outputting it to the transmitting antenna 4, 8 is 1
It 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 transmitter / receiver 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 °, and then amplifies it to an equal amplitude and then the other radar Send to.

The receiving antenna 1 installed near the transmitting antenna 3 receives radio waves from the 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, amplified here, and then output to the transmission antenna 4. The transmission antenna 4 transmits the amplified reception signal. On the other hand, the receiving antenna 2 installed near the transmitting antenna 4 also receives the radio wave from the radar. This received signal is input to the 180 ° phase converter 6, where the phase is shifted (reversed) 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. Transmitting antenna 3
Transmits the amplified received signal.

When the transmitter / receiver of FIG. 11 operates in this way, the angle tracking radar such as a monopulse radar, in addition to the original received signal reflected by the airframe of the aircraft, the amplified signal from the transmitting antenna 4 and the transmitting antenna. Since the amplified signals (these signals have the same amplitude) out of phase with each other from 3 are received at the same time, the normal angle measurement is not performed, and an error occurs in the angle measured for the aircraft.

[0006]

The conventional transmitting / receiving device is
It is configured as described above, and it is difficult to secure the isolation because the receiving operation and the transmitting operation are performed at the same time. If the isolation cannot be secured, the radio wave transmitted by itself will be received by its own reception antenna, processed, and transmitted again, so a closed loop of processing may be configured and fall into the oscillation state. Sometimes the phase difference could not be secured and the jamming performance deteriorated. In addition, the phase may change due to various causes, and it may not be possible to effectively interfere with the radar of the other party.

The present invention has been made to solve the above problems, and an object thereof is to obtain a transmission / reception apparatus in which the interference performance is not deteriorated.

[0008]

According to a first aspect of the present invention, there is provided a transmitting / receiving apparatus, wherein the distance between a first receiving antenna and a first transmitting antenna and the distance between a second receiving antenna and a second transmitting antenna are both set. In addition to increasing the distance, the distance between the target and the first receiving antenna, the total distance between the target and the first transmitting antenna, the distance between the target and the second receiving antenna, and the target and the first It is arranged so that the total distance from the two transmitting antennas is equal.

A transmitter / receiver according to a second aspect of the present invention includes a pseudo signal generating circuit for simulating a signal sneaking around from the second transmitting antenna to the first receiving antenna based on the output of the second amplifier,
And a subtractor for subtracting the output signal of the pseudo signal generating circuit from the output signal of the first receiving antenna.

According to a third aspect of the present invention, there is provided a transmitting / receiving apparatus, wherein a phase comparator for obtaining a 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, and the phase comparator. And a phase shifter that adjusts the phase of the output signal of the first receiving antenna based on the output of the comparator.

According to a fourth aspect of the present invention, there is provided a transmission / reception apparatus which includes, instead of the phase converter, a phase changer for changing the phase of the output signal of the second receiving antenna within a predetermined range.

According to a fifth aspect of the present invention, there is provided a transmitting / receiving apparatus which comprises a first frequency converter for converting the output signal of the second receiving antenna into a low frequency signal and a second frequency converter for converting the output signal of the phase converter into a high frequency signal. And a frequency converter, wherein the phase converter is characterized by converting a phase at a low frequency.

According to a sixth aspect of the present invention, there is provided a transmitting / receiving apparatus, which includes a first delay line for delaying an output signal of a first receiving antenna, and a second delay line.
And a second delay line for delaying the output signal of the receiving antenna.

According to a seventh 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
The pulse width is the same as the pulse width of the radio wave transmitted from the target.

[0015]

According to the first aspect of the invention, the first receiving antenna and the first transmitting antenna, and the second receiving antenna and the second transmitting antenna are arranged separately from each other, so that the mutual coupling is reduced. At the same time, the distance between the target and the first receiving antenna, the total distance between the target and the first transmitting antenna, the distance between the target and the second receiving antenna, and the target and the second By arranging so that the total distance to the transmitting antenna is equal, the line length in space becomes the same.

According to another aspect of the present invention, the pseudo signal generating circuit generates a pseudo signal simulating a signal sneaking into the first receiving antenna from the second transmitting antenna based on the output of the second amplifier, and the subtractor The output signal of the pseudo signal generating circuit is subtracted from the output signal of the first receiving antenna.

In the third aspect of the invention, the phase comparator obtains 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, and compares the phase difference with a phase shifter. Adjusts the phase of the output signal of the first receiving antenna based on the output of the phase comparator so that the phase difference becomes a predetermined phase difference.

In a fourth aspect of the invention, the phase changer changes the phase of the output signal of the second receiving antenna within a predetermined range.

According to the invention of claim 5, 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. Converting to a high frequency signal, the phase converter converts the phase at low frequencies.

In a sixth 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 set a transmission period. Try not to match the reception period.

In the invention of claim 7, the first delay line and the second delay line delay the received signal by the same time as the pulse width of the radio wave transmitted by the target.

[0022]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a functional block diagram of the transmitting / receiving apparatus according to the first embodiment. In the figure, 1 and 2 are receiving antennas for receiving radio waves transmitted from a radar device on the other side that causes an error, 3 and 4 are transmitting antennas for transmitting radio waves to the radar device on the other side, and 6 is a receiving antenna 2 180 ° phase converter that inverts the phase of the signal received at, 7 is an amplifier that amplifies the output of the sneak wave removal circuit 17 and outputs it to the transmitting antenna 4, 8 is amplifies the output of the 180 ° phase converter and transmits Amplifiers to be output to the antenna 3, 9 and 11 are receivers for receiving the radio waves received by the receiving antennas 1 and 2, and 10 and 12 are receivers for receiving and processing a part of the outputs of the amplifiers 8 and 7, 13 Reference numerals 16 to 16 denote A / D converters for converting the outputs of the receivers 9 to 12 from analog signals to digital signals, and 17 denotes A / D converter 1.
A sneak wave removal circuit that removes radio waves that sneak from the transmitting antenna to the reception antenna based on the outputs of 3 and 14, 18 is a sneak wave removal circuit that also processes the outputs of the A / D converters 15 and 16, and 19 is a sneak wave removal circuit. D which converts the digital output of 17 into an analog signal and outputs it to the amplifier 7
A / A converter, 20 is a D / A for converting the digital output of the 180 ° phase converter 6 into an analog signal and outputting it 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 radar device of the other party. Also,
a, d, c, and b are the positions P of the opponent radar devices, respectively.
Is the distance between the receiving antennas 1 and 2 and the transmitting antennas 3 and 4.

FIG. 3 shows a wraparound wave elimination circuit 1 of FIG.
It is an internal block diagram of 7, 18, and in the figure, 10
1a to 101c are delay circuits for delaying a transmission signal, 10
2a to 102d are coefficient multipliers that multiply the transmission signal and the delayed transmission signal by a predetermined coefficient, and 103 is a combiner that combines the outputs of the coefficient multipliers 102a to 102d.
Reference numeral 4 is a subtracter that subtracts the output of the combiner 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 radar of the other party. This received signal is converted into a signal having a predetermined frequency by the receiving unit 9 and then the A / D converter 1
It is converted into a digital signal by 3. A / D converter 13
The output signal of 1 is input to the D / A converter 19 after the wraparound wave removal circuit 17 removes the wraparound wave signal to some extent. The operation of the sneak wave removing circuit 17 will be described later. The output of the sneak wave removing circuit 17 is D /
After being converted into an analog signal by the A converter 19, the signal is input to the amplifier 7, and after being amplified here, the directional coupler 2
It is output to the transmitting antenna 4 via 2. The transmission antenna 4 transmits the amplified reception signal.

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

A feature of the transmitting / receiving apparatus of the first embodiment is that the receiving antennas 1 and 2 and the transmitting antennas 3 and 4 are arranged as shown in FIG. 2 in order to ensure isolation between the received signal and the transmitted signal. And the sneak wave elimination 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 is, the smaller the coupling between them becomes. Therefore, in order to secure isolation, the distance between the receiving antenna 1 and the transmitting antenna 4 and the distance between the receiving antenna 2 and the transmitting antenna 3 are required. All distances should be long. However, in order for the transmission / reception device using this cross-eye to exhibit its performance, a certain distance is required between the transmission antenna 3 and the transmission antenna 4 in terms of the operating principle. Furthermore, the total of the distance between the other party's radar (P in FIG. 2) and the receiving antenna 1 (a in FIG. 2) and the distance between the other party's radar and the transmitting antenna 4 (b in FIG. 2), and the other party's radar and receiving The distance between the antenna 2 (d in FIG. 2) and the total distance between the other radar and the transmitting antenna 3 (c in FIG. 2) must be equal.
That is, a + b = c + d. If this condition is not satisfied, the receiving antenna 1 and the transmitting antenna 4
Since there is a difference in the line length in the free space between the signal of the system due to and the signal of the system due to the receiving antenna 2 and the transmitting antenna 3, it is possible to maintain the phase difference of the signal received by the radar of the other party at a predetermined value. Because it will not be possible.

The arrangement shown in FIG. 2 is an example of the arrangement that satisfies these conditions. That is, the receiving antenna 1 and the transmitting antenna 3, the receiving antenna 2 and the transmitting antenna 4,
The antennas are arranged close to each other and are arranged so that the corresponding transmitting antennas and receiving antennas are symmetrical with respect to an intermediate point between the receiving antenna 1, the transmitting antenna 3, the receiving antenna 2 and the transmitting antenna 4. Furthermore, 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 can be increased to achieve isolation, and the distance between the transmitting antennas can be increased, and the line length condition can be satisfied. Performance does not decrease.

Next, the operation of the sneak wave removing circuits 17 and 18 will be described with reference to FIGS. The operation principle of the sneak wave removing circuits 17 and 18 is that the degree of the sneak wave generated in the received signal is obtained in advance by calculation or experiment, and the same signal as the sneak wave is generated based on the transmission signal and the received signal is received. It is intended to remove only the wraparound wave by subtracting it from the signal.

In FIG. 1, the output signal of the amplifier 8 is radiated into space by the transmitting antenna 3, but the directional coupler 2
A part thereof 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 the sneak wave removing circuit 17 is provided.
Is input as a transmission signal. This transmission signal is sequentially delayed by a predetermined time by 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 a predetermined coefficient. The delay time and the coefficient are predetermined by calculation or the like so that the amount of wraparound from the transmitting antenna to the receiving antenna can be calculated based on the actual arrangement of the receiving antenna and the transmitting antenna (for example, the arrangement of FIG. 2).

The synthesizer 103 is provided for these coefficient multipliers 102.
By synthesizing the outputs of a to 102d, a sneak wave pseudo signal to be superimposed on the received signal is generated. The delay circuit, the coefficient multiplier, and the combiner simulate the transfer function of the wraparound from the transmitting antenna to the receiving antenna. Then, the subtracter 104 uses the received signal to synthesize the synthesizer 10
The pseudo signal of the wraparound wave output by 3 is subtracted, and is output to the D / A converter 19 as a received wave after the wraparound wave is removed. The operation of the sneak wave removing circuit 18 is similar. In this way, since the sneak wave pseudo signal is removed from the received signal, if the sneak wave pseudo signal output from the combiner 103 is the same as the actual sneak wave signal, the reception signal from the other radar is affected. The wraparound wave can be eliminated without giving Although the delay circuit 101 has three stages in FIG. 3, the present invention is not limited to this, and may have four or more stages.

When the transmitting / receiving apparatus of FIG. 1 operates as described above, the angle tracking radar such as a monopulse radar, in addition to the original received signal reflected by the airframe of the aircraft, the amplified signal from the transmitting antenna 4 and the transmitted signal. Since an amplified signal with a phase difference of 180 ° from the antenna 3 is received at the same time, 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 on a one-to-one basis, such as a monopulse system or a conical scan system, operates so as to face the phase wavefront of the radio wave reflected by the target and tracks the target.
In a radar having such characteristics, when cross-eye jamming using two transmission sources with different phases is caused, the interference phenomenon causes a distortion in the phase wavefront, which increases the angle tracking error. The value of this angular error is determined by the distance between the two transmitting antennas and the phase difference and amplitude ratio of the radio waves emitted from them. The longer the distance between the transmitting antennas, the larger the angle error. Also, the closer the phase difference is 180 ° and the amplitude ratio is to 1, the larger the angle error.

In the transmitter / receiver of FIG. 1, the receiving antenna and the transmitting antenna are arranged as shown in FIG.
Since the sneak wave removing circuits 17 and 18 are provided, isolation can be secured.

As described above, according to the transmitter / receiver of the first embodiment, the isolation can be sufficiently secured, the closed loop of the processing is not formed, and the stable operation can be realized. The jamming performance is improved.

Since the transmitter / receiver of FIG. 1 performs digital processing, it can perform more accurate and stable processing than the analog method, and can keep the phase difference at a predetermined value accurately and stably. Performance is improved.

Further, in the first embodiment, by the arrangement of the transmitting antenna and the receiving antenna capable of taking isolation and the sneak wave removing circuit,
Although high isolation has been realized, it goes without saying that the isolation is improved even if only one of them, that is, the arrangement of the transmitting antenna and the receiving antenna or only one of the sneak wave removing circuits is used.

Embodiment 2 FIG. In the first embodiment described above, the phase of the output signal of the sneak wave removing circuit 17 was not adjusted, but by providing the phase shifter capable of varying the phase amount,
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 indicates the phase of the signal transmitted from the transmitting antenna 3 and the phase of the signal transmitting from the transmitting antenna 4. A phase comparator for comparing and obtaining the phase difference between them, 31 is a phase shifter for adjusting the phase shift amount of the signal received by the receiving antenna 1 based on the output signal of the phase comparator 30, and 32 is the output of the amplifier 8 for the transmitting antenna. 3 and supplies a part of them to the receiver 10 and the phase comparator 30.
And 33 is a directional coupler that supplies the output of the amplifier 7 to the transmitting antenna 4 and distributes a part of it to the receiving unit 12 and the phase comparator 30.

The receiving antennas 1 and 2, the transmitting antennas 3 and 4, the 180 ° phase converter 6, the amplifiers 7 and 8, the receiving units 9 to 12, the A / D converters 13 to 16, the wraparound wave removing circuit 17, 18, 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 device, it is important to isolate transmission and reception, but in order to cause angular fraud in the other party's radar, it is necessary to exactly invert the phase by 180 °. Phase comparator 3 in the second embodiment
The 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 transmitting antenna 3 with the radio wave output from the transmitting antenna 4, and obtains the phase difference between them. This phase difference is 1
When the angle is 80 °, the transmitting / receiving apparatus of the second embodiment exhibits the best performance, and 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, and the sneak wave removing circuit is provided.
Further, since the phase comparator and the phase shifter controlled thereby are provided, a predetermined phase difference is maintained between the transmission signals even when the line length is changed due to temperature change or the like and the phase difference is changed. The performance of the transmitter / receiver does not deteriorate.

Example 3. In the second embodiment, the transmission / reception device that maintains the predetermined phase difference by performing control so as to reduce the phase error based on the comparison result of the phases of the transmission signals has been described. However, the phase difference is more positive than 180 °. The angle 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 is a phase changer for changing the phase of the reception signal of the reception 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,
Circular wave elimination circuits 17, 18, D / A converters 19, 2
0 and the directional couplers 21 and 22 are the same as those shown in FIG.

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

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

As described above, according to the third embodiment, the transmitting antenna and the receiving antenna are arranged so as to be isolated, and the sneak wave removing circuit is provided.
Furthermore, since the phase ratio variable device that changes the phase is provided, even if the line length changes due to temperature changes, etc., and the phase difference changes, the point that the phase difference is 180 ° is stochastically obtained, and It is possible to reduce the possibility that the effect is not obtained. In addition, according to the third embodiment, the phase shifter and the 180 ° phase converter that are required in the first and second embodiments are not necessary.

Example 4. Although the first to third embodiments show the transmitting / receiving device which converts the received signal into the digital signal and then processes the signal, the high frequency signal is converted into the low frequency signal (intermediate frequency signal) and the analog signal is processed as it is. You may

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 the phase difference between the signal transmitted from the transmission antenna 3 and the signal transmitted from the transmission antenna 4, 25 is a local oscillator for generating a local signal, and 26 and 28 are local oscillators. Frequency converters that convert a high frequency signal into a low frequency signal based on the output of the oscillator 25, and 27 and 29 are frequency converters that convert a low frequency signal into 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. This Example 4
The transmitting / receiving device according to (1) operates in the same manner as in the first embodiment except that it operates in analog and does not remove the wraparound wave. Further, according to the fourth embodiment, since the processing of the phase of the received signal is performed after converting it to a low frequency, the influence of the error in the transmission line length can be reduced and the phase adjustment can be facilitated.

For example, when the frequency of the received signal is 1 GHz and the wavelength shortening rate by the line is 70%, the wavelength becomes λ '= 210 mm. At this time, the transmission line length is 6 m
When an error of m occurs, the phase shifts by 10 °, and the jamming performance is greatly reduced. However, if the frequency is converted to 100 MHz by the frequency converters 26 and 28, the wavelength will be reduced to 1/10, and the wavelength will deviate by only 1 °, and the jamming performance will not be lowered so much. Also, when adjusting the phase, the same transmission line length can be used to make delicate adjustments, which facilitates the adjustment. After the predetermined phase processing is performed at a low frequency, the frequency converters 27 and 29 convert the signal again to a high frequency signal for amplification and radiate it from the transmitting 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 converting it to the low frequency.
The influence of the error of the transmission line length can be reduced, and the phase adjustment can be facilitated to improve the jamming performance.

Note that the transmission / reception apparatus of FIG. 7 does not have a sneak wave removing circuit, but may have a configuration having a sneak wave removing circuit as shown in FIG. In this case, the operation is the same except that the processing is done with analog signals. Further, the antennas 1 to 4 may be arranged as shown in FIG.

Example 5. In the first embodiment described above, the transmission / reception device that removes the wraparound wave using the wraparound wave removal circuit has been described, but the present invention is not limited to this, and the wraparound wave may be removed by a time division method. This embodiment 5 is shown in FIG.
2 is a functional block diagram of the transceiver device of FIG. In the figure,
Reference numerals 23 and 24 are delay lines that delay the signals received by the receiving antennas 1 and 2 by a delay time considering the pulse width of the radar of the other party. The receiving antennas 1 and 2, the transmitting antennas 3 and 4, the phase shifter 5, and the 180 ° phase converter 6,
The amplifiers 7 and 8 are the same as those shown in FIG.

Next, the operation will be described. This Example 5
Then, transmission is performed after a certain delay time so that reception and transmission are not performed at the same time, thereby ensuring isolation between transmission and reception. For example, as shown in the timing chart of FIG. 4, the receiving antennas 1 and 2 first perform reception processing, and then the transmission antennas 3 and 4 perform transmission after a predetermined time has elapsed due to the processing of the delay lines 23 and 24. Then, this operation is repeated. By alternately repeating transmission and reception in this way, transmission and reception are not performed at the same time, so that the wraparound is reduced.

By the way, if the delay time of the delay lines 23 and 24 is too long, in the reception signal of the radar of the other party, the signal by this transmitting / receiving device and the reflected signal by the aircraft on which this transmitting / receiving device is mounted are separated, so that the effect of interference is obtained. Is reduced. 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 also changes correspondingly. By setting the delay time in this way, isolation can be ensured without reducing the effect of interference.

As described above, according to the transmitter / receiver of the fifth embodiment, sufficient isolation can be secured, a closed loop of processing is not formed, and stable operation is possible. The jamming performance is improved.

Further, in the fifth embodiment, a combination of the arrangement of the transmitting antenna and the receiving antenna capable of achieving isolation and the sneak wave removing circuit as in the first embodiment may be applied. , Higher isolation can be achieved.

[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 both determined. And the distance between the target and the first receiving antenna, the total distance between the target and the first transmitting antenna, the distance between the target and the second receiving antenna, and the target and the above. Since it is arranged so that the total distance from the second transmitting antenna is equal, it is possible to secure the isolation, stabilize the operation, and prevent the performance of the transmitter / receiver from deteriorating.

According to the invention of claim 2, a pseudo signal generating circuit for simulating a signal sneaking from the second transmitting antenna to the first receiving antenna based on the output of the second amplifier, and the pseudo signal generating circuit. Since the output signal of 1 is subtracted from the output signal of the first receiving antenna, the isolation can be further increased.

Further, according to the invention of claim 3, a phase comparator for obtaining a 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,
Since the phase shifter that adjusts the phase of the output signal of the first receiving antenna based on the output of the phase comparator is provided, even if the line length changes and the phase difference changes, the transmission signal In, the predetermined phase difference is maintained, and it is possible to prevent the performance of the transmission / reception device from deteriorating.

Further, according to the invention of claim 4, instead of the phase converter, a phase variable device for changing the phase of the output signal of the second receiving antenna within a predetermined range is provided. Even if the phase difference changes due to the change in the line length, it is possible to stochastically operate with an effective phase difference, and it is possible to prevent the performance of the transmission / reception device from deteriorating.

According to the invention of claim 5, a first frequency converter for converting the output signal of the second receiving antenna into a low frequency signal and a first frequency converter for converting the output signal of the phase converter into a high frequency signal. Since the phase converter converts the phase at a low frequency, it is possible to reduce the influence of the error in the transmission line length and prevent the performance of the transmitter / receiver from deteriorating.

Further, according to the invention of claim 6, a first delay line for delaying the output signal of the first receiving antenna and a second delay line for delaying the output signal of the second receiving antenna are provided. Since it is provided, isolation can be ensured with a simple configuration, and deterioration of the performance of the transmission / reception device can be prevented.

According to the invention of claim 7, the first
Since the delay time of the delay line and the delay time of the second delay line are set to be the same as the pulse width of the radio wave transmitted by the target, it is possible to ensure isolation without degrading the function.

[Brief description of 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 a layout diagram of antennas of the transmitting / receiving apparatus according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram of a sneak wave cancel circuit of the transceiver 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 transmitter / receiver according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of the operation of the phase varying device of the transmitting / receiving apparatus according to the third embodiment of the present invention.

FIG. 7 is a functional block diagram of a transmitter / receiver according to a fourth embodiment of the present invention.

FIG. 8 is a functional block diagram of a transmitter / receiver according to a fifth embodiment of the present invention.

FIG. 9 is an operation timing chart of the transmission / reception device according to the fifth embodiment of the present invention.

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

FIG. 11 is a functional block diagram of a conventional transceiver.

[Explanation of symbols]

1, 2 receiving antennas, 3 and 4 transmitting antennas, 5 phase shifters, 6 180 ° phase converters, 7 and 8 amplifiers, 9 to
12 receiver, 13 to 16 A / D converter, 17 and 18
Circular wave elimination 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.

Claims (7)

[Claims] 1. A first receiving antenna for receiving a radio wave emitted from a target, a first amplifier for amplifying an output signal of the first receiving antenna, and a radio wave for receiving an output signal of the first amplifier. Of the phase shifter for converting the phase of the output signal of the second receiving antenna, the second receiving antenna for receiving the radio wave emitted by the target, A transmitting / receiving device comprising: a second amplifier for amplifying an output signal; and a second transmitting antenna for receiving an output signal of the second amplifier and transmitting a radio wave, the first receiving antenna and the first transmitting antenna. The distance between the antenna and the distance between the second receiving antenna and the second transmitting antenna are both increased, and the distance between the target and the first receiving antenna and the distance between the target and the first transmitting antenna are increased. And a distance between the target and the second receiving antenna and a total distance between the target and the second transmitting antenna are equal to each other. apparatus. 2. A pseudo signal generating circuit for simulating a signal sneaking into the first receiving antenna from the second transmitting antenna based on an output of the second amplifier, and an output signal of the pseudo signal generating circuit for the output signal of the pseudo signal generating circuit. The transmitter / receiver according to claim 1, further comprising: a subtractor that subtracts from an output signal of one reception antenna. 3. The output signal of the first amplifier and the second signal of the second amplifier.
A phase comparator for obtaining a phase difference from the output signal of the amplifier and comparing it with a predetermined phase difference, and a phase shift for adjusting the phase of the output signal of the first receiving antenna based on the output of the phase comparator. The transmitter / receiver according to claim 1, further comprising: 4. 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.
The described transceiver device. 5. A first frequency converter for converting the output signal of the second receiving antenna into a low frequency signal, and a second frequency converter for converting the output signal of the phase converter into a high frequency signal. The transmitter / receiver according to claim 1, further comprising a phase converter that converts a phase at a low frequency. 6. A first receiving antenna for receiving a radio wave emitted from a target, a first amplifier for amplifying an output signal of the first receiving antenna, and a radio wave for receiving an output signal of the first amplifier. Of the phase shifter for converting the phase of the output signal of the second receiving antenna, the second receiving antenna for receiving the radio wave emitted by the target, A transmission / reception device comprising a second amplifier for amplifying an output signal and a second transmitting antenna for receiving an output signal of the second amplifier and transmitting a radio wave, wherein the output signal of the first receiving antenna is delayed. A transmitting / receiving apparatus comprising: a first delay line; and a second delay line that delays an output signal of the second receiving antenna. 7. The transceiver according to claim 6, 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.