JP2002207075A - Radio wave jammer - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object to transmit an interference wave until immediately before a reception gate for receiving a radar pulse is opened. [Structure] Receiving and storing the radar pulse signal of the other party,
The Doppler modulation is applied to this to generate an interfering wave, and in a radio wave jammer of a system that continuously bounces back to the other party, the information on the repetition frequency (PRI) of the received radar pulse and the Doppler modulation frequency (fd) set by itself is used. A filter unit 42a that realizes a plurality of types of filters that match the received radar pulse and that can suppress the reflected wave signal of the interfering wave transmitted by itself, and each output that passes the received radar pulse through a plurality of types of filters in advance. A maximum value detection unit 42b that detects a filter that best matches the received radar pulse based on
A storage / reproducing unit 33 for storing and reproducing the detected radar pulse signal of the filter output for generating an interference wave;

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave jammer, and more particularly, to a method of receiving and storing a radar pulse signal of a partner, applying Doppler modulation to the radar pulse signal to generate a disturbance wave, and continuously returning the same to the partner. Related to radio interference equipment.

In this type of apparatus, an effective interference wave can be generated by more accurately receiving and storing the radar pulse signal waveform of the other party, and a large interference effect can be obtained.

[0003]

2. Description of the Related Art FIGS. 16 and 17 are diagrams (1) and (2) for explaining the prior art, and FIG. 16 (A) shows an environment in which a radio wave jamming system is used. In the figure, reference numeral 10 denotes a counterpart radar apparatus, 20 denotes a target, 20 ′ denotes a pseudo target appearing on a radar scope, and 30 ′ denotes a conventional radio wave jammer.

[0004] The radar apparatus 10 repeatedly transmits radar pulses having a carrier frequency fr with a substantially predetermined period PRI. The radio wave jamming device 30 ′ normally receives and stores radar pulses via side lobes of the radar device 10, applies Doppler modulation of the frequency fd to the reproduced radar pulses to generate jamming waves, and continuously generates these waves. A reciprocal action is taken to perform a disturbing action.

FIG. 16B is a block diagram of a conventional radio wave jammer, in which 30 'is a radio wave jammer and 31'
Is an antenna, 32 'is a transmission / reception unit, 33' is a storage / reproduction unit for a received radar pulse signal, 34 'is a Doppler modulation unit for the reproduced radar pulse signal, 35' is a control unit for controlling the above units, Reference numeral 100 denotes an analyzer that analyzes the detailed specifications (fr, PRI, etc.) of the radar device 10 based on a series of received radar pulses.

FIG. 17A shows a conventional radio wave jamming device 10 ′.
3 shows a timing chart of a desirable disturbance operation of the present invention. The reception gate is opened at the timing (PRI) predicted by the analyzer 100, and the radar pulse P1 arriving during this period is received and stored. Then, the stored radar pulse signals P1 are successively arranged and repeatedly reproduced in a section T until the next radar pulse P2 arrives, and these are subjected to Doppler modulation to be returned to the radar apparatus 10. The same applies to reception after the radar pulse P2.

The interfering wave that has entered the radar device 10 is a signal obtained by subjecting the radar pulse P1 generated by the radar device 10 to Doppler modulation, and thus is not removed by MTI processing or the like in the radar device 10 and the original radar signal. It is displayed on the radar scope like an echo. Also, by continuously hitting the interfering wave, a large number of pseudo targets 20 'appear on the radar scope, thereby effectively hiding the original target 20. Therefore, in order to exhibit such an interference effect, it is necessary for the radio wave interference device 30 'to receive and store a pure radar pulse waveform as much as possible. Further, it is desirable to transmit as many interference wave pulses as possible in the arrival section of each radar pulse.

However, as shown in FIG. 17 (A), in the method of transmitting an interference wave until immediately before the next reception gate is opened, a reflected wave of the interference wave transmitted immediately before the reception gate is opened (hereinafter referred to as interference reflection). Wave) is received in a form superimposed on the original radar pulse, so that the interference wave generated based on this received signal is different from the interference wave generated based on the pure radar pulse. The effect decreases. Furthermore,
By repeating the reception of the radar pulse and the transmission sequence of the interference wave, the ratio of the past interference wave component to the interference wave gradually increases, and the interference effect gradually decreases.

Further, as shown in FIG. 17A, a method of transmitting an interference wave until immediately before the next reception gate is opened,
For example, since the transmitted interfering wave is reflected in the surrounding radar environment (mountain etc.), if the level of the reflected wave is high, the receiving gate is opened and simultaneously the interfering reflected wave that arrives before the original radar pulse is opened. There is also a risk of detection as a radar pulse.

Therefore, conventionally, as shown in FIG. 17B, a time T _{abs at} which the interfering reflected wave is sufficiently attenuated is considered,
Timing before opening the reception gate (T-T _abs )
The transmission of interfering waves had been discontinued.

[0011]

However, if the method of shortening the transmission period of the interfering wave as in the above-described conventional method is used, the number of pseudo targets 20 'appearing on the radar scope is reduced, and the interfering effect is significantly reduced. I was

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and has as its object to provide a radio wave jamming device capable of transmitting an interfering wave until immediately before a receiving gate for receiving a radar pulse is opened. It is in.

[0013]

The above-mentioned problem is solved, for example, by referring to FIG.
Is solved. That is, the radio wave jamming device of the present invention (1) receives and stores the radar pulse signal of the other party,
The Doppler modulation is applied to this to generate an interfering wave, and in a radio wave jammer of a system that continuously bounces back to the other party, the information on the repetition frequency (PRI) of the received radar pulse and the Doppler modulation frequency (fd) set by itself is used. A filter unit 42a that realizes a plurality of types of filters that match the received radar pulse and that can suppress the reflected wave signal of the interfering wave transmitted by itself, and each output that passes the received radar pulse through a plurality of types of filters in advance. A maximum value detection unit 42b that detects a filter that best matches the received radar pulse based on
A storage / reproducing unit 33 for storing and reproducing the detected radar output pulse signal of the filter for generating an interference wave;

According to the present invention (1), even if an interfering wave is transmitted until immediately before the reception gate is opened, the immediately following radar reception signal (radar wave + interfering reflected wave) matches the radar wave component and Since the interference reflected wave component can be sufficiently removed by the filter capable of suppressing the interference reflected wave component, it is possible to strike back a number of effective interference waves based on the obtained radar pulse for generating the interference wave, thereby enhancing the interference effect. be able to.

The above problem is solved by, for example, the configuration shown in FIG. That is, the radio wave jammer of the present invention (2) is a radio wave jammer of a system that receives and stores a radar pulse signal of the other party, performs Doppler modulation on the signal, generates an interference wave, and continuously bounces the other party. An interfering reflected wave storage / reproducing unit 50 which receives and stores a reflected wave signal of the interfering wave transmitted immediately before, and reproduces the received reflected wave signal when receiving a subsequent radar pulse;
A subtraction unit 51 for subtracting the stored and reproduced interference reflected wave signal from the received radar pulse signal, and a storage / reproduction unit 33 for storing and reproducing the radar pulse signal output from the subtraction unit 51 for generating an interference wave are provided. Things.

According to the present invention (2), even if the interfering wave is transmitted until immediately before the reception gate is opened, the subtraction unit 51 subtracts the immediately following radar reception signal (radar wave + interference reflected wave).
It is possible to sufficiently remove (subtract) the interfering reflected wave component sampled in advance and stored in the interfering reflected wave storage / reproducing unit 50 and reproduced, so that a number of effective interfering waves are returned based on the obtained interfering wave generation radar pulse. Is possible, so that the interference effect can be enhanced.

The above problem is solved by, for example, the configuration shown in FIG. That is, the radio wave jamming device of the present invention (3)
A receiving system antenna 31b that receives and stores a radar pulse signal of the other party, performs Doppler modulation on the signal, generates an interfering wave, and continuously bounces back to the other party. And a transmission system antenna 31a that transmits the signals so that their polarization planes are orthogonal to each other.

According to the present invention (3), by making the two polarization planes related to the transmission of the interfering wave and the reception of the reflected wave orthogonal to each other (with an isolation relationship), the interfering reflected wave is generated in the radar pulse receiving system. Since no components can enter and thus a number of effective interference waves can be transmitted until immediately before the reception gate is opened, the interference effect can be greatly increased.

[0019]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that
Throughout the drawings, the same reference numerals indicate the same or corresponding parts.

FIG. 1 is a configuration diagram of a main part of a radio wave jamming device according to a first embodiment, and shows a case where a jamming reflected wave component is removed from a radar reception signal by a filter. In the figure, reference numeral 30 denotes a radio wave jammer according to the first embodiment, 31
Is an antenna, 32 is a transmission / reception unit, 40 is an interference reflection wave suppression filter unit that removes (suppresses) interference reflection wave components from radar reception signals, 41 is a filter unit that can implement a plurality of types of filter characteristics in advance, and 42 is A maximum value detection unit that detects and holds an optimum filter characteristic that most closely matches the reception radar pulse and suppresses the interfering reflected wave, 33 is a storage / reproduction unit for the reception radar pulse that has passed through the optimum filter, and 34 is a reproduction radar A pulse Doppler modulator 35, a controller 35 for controlling the above components, and an analyzer 100 for analyzing detailed specifications (fr, PRI, etc.) of the radar apparatus 10 based on a series of received radar pulses.

The desired jamming wave to be transmitted by the radio wave jamming device is obtained by subjecting a pure received radar pulse to Doppler modulation of a required frequency fd, so that the interference between the radar wave component fr and the jamming reflected wave component (fr + fd) is obtained. Is the Doppler modulation frequency f
There is a difference of d minutes. In the first embodiment, attention is paid to the frequency difference fd, and the interference reflected wave component is effectively removed from the radar reception signal.

FIG. 2 is a diagram for explaining the principle of suppression of interference reflected waves by a filter. The detailed specifications (fr, P
RI or the like can be predicted in advance with high accuracy. FIG. 2A shows the spectrum of a radar pulse received by the periodic PRI. The solid line shows the line spectrum of the radar wave component, and the dotted line shows the line spectrum of the interfering reflected wave component. The spacing between the line spectra is PRF (= 1 / PRI) for both the radar wave component and the interfering reflected wave component, but the Doppler modulation frequency fd is between the radar wave component and the interfering reflected wave component.
There is a minute gap. FIG. 2B shows a filter characteristic capable of removing the interfering reflected wave component of FIG. 2A, which is a characteristic that allows the radar wave component to pass but does not allow the interfering reflected wave component to pass. In FIG. 2 (C), by passing the radar reception signal through the filter, the interference reflected wave component is effectively removed (suppressed), and only the radar wave component is extracted.

However, in practice, it is impossible to accurately know the detailed specifications (fr, PRI, etc.) of the radar device 10 in advance. Therefore, an example of an interference reflected wave suppression filter that can appropriately cope with such a situation will be described in detail below.

FIG. 3 is a block diagram of the interference reflection wave suppression filter unit according to the first embodiment, showing a case where different filter characteristics are realized by a plurality of filter circuits. FIG.
4A, reference numeral 41a denotes a filter unit, F1 to F2N denote filter circuits (FIR filters) provided in parallel with a plurality of radar reception signals, and SEL denotes filters F1 to F2.
An N output selection circuit (selector) 42a is a maximum value detection unit that detects and holds the optimum filter characteristic that most matches the reception radar pulse and that can sufficiently suppress the interfering reflected wave, and DT1 to DT2N are filters F1. , F2N,..., F2N, a signal detection unit for obtaining amplitude detection, a signal average value, a signal power, and the like.
DT2N is a maximum filter detecting / holding unit that detects the maximum value of the output and holds the number of the corresponding filter. The required number of filter circuits = 2N is the modulation Doppler frequency f
d = ± PRF / N.

The repetition frequency PRF (= 1 / PRI) of the radar pulse obtained by the reception analysis of the analyzer 100
And the Doppler modulation frequency f determined by the radio wave jamming device 30
Based on d, filter coefficient vectors W (1) to W (2N) are generated to cover the passage of the radar wave component and to suppress the interfering reflected wave component, and are added to the filters F1 to F2N. Can be The filters F1 to F2N each perform a filtering process on the radar reception signal according to the filter coefficient vectors W (1) to W (2N).

FIG. 3B shows circuit examples (a) and (b) of the digital FIR filter. Here, for simplification of description, the case of 4P-DFT (corresponding to N = 2) is shown. In the figure, D is a delay circuit, X is a multiplier, + is an adder, and w1 to w4 are filter coefficients. The frequency characteristics of the FIR filters (a) and (b) are the same.

FIG. 4 shows an example of a filter characteristic by 4P-DFT (N = 2). The frequency characteristics of the filters F1 to F4 are such that the passband is fd / 2 and the repetition period (sampling frequency) of the filter is 2 × fd (= PRF), but the offset frequency is 0, fd / 2, fd and 3fd / 2. The contents of the filter coefficient vectors W (1) to W (4) are additionally shown in the figure.

Returning to FIG. 3A, the interference reflected wave suppression filter section 40 transmits an effective interference wave by using an interference preparation period for detecting an optimum filter in advance and the detected optimum filter. Different operations are performed in the two phases of the disturbance period. In the jamming preparation period, the radar reception signal (pure radar pulse P
1 to Pn) are passed through the filters F1 to F2N, the maximum value detection unit 42a detects which filter output has the maximum amplitude (or electric power or the like), and stores the filter number of the maximum output. During this period, since no interfering wave is transmitted, no signal is output to the storage / reproduction unit 33 in the subsequent stage, and the storage / reproduction unit 33 does not operate.

In the subsequent disturbance period, the filters F1 to F2N
Among them, only the output of the filter designated by the maximum value detection unit 42a is selected by the selector SEL and sent to the storage / reproduction unit 33 in the subsequent stage. At this time, since only the filter that most closely matches the carrier frequency fr of the received radar pulse and has a sufficient suppression effect on the interfering reflected wave is selected, the received signal sent to the storage / reproduction unit 33 Most of the interference reflected wave components have been removed.

Returning to FIG. 1, the storage / reproduction unit 33 stores the radar pulse signal from which the interfering reflected wave component has been removed,
Under the control of the control unit 35, the stored radar pulse signal is repeatedly reproduced. The repeatedly reproduced radar pulse signal is subjected to a Doppler modulation frequency fd
(= ± PRF / 2).
The signal is amplified by the receiving unit 32 and transmitted to the radar device 10 as an interference wave via the antenna 31 as an interference wave.

When the radio wave jammer 30 changes the Doppler modulation frequency fd, it is necessary to change the characteristics of the filters F1 to F2N. Therefore, the operation sequence from the jammer preparation period is executed again. Further, since the radar device 10 changes the frequency (frequency hop, etc.) at an arbitrary timing, the operation sequence from the interference preparation period is re-executed at a predetermined cycle in order to adapt the filter characteristic to the filter characteristic. Reconfigure and select.

FIG. 5 is a block diagram of an interference reflected wave suppression filter unit according to the second embodiment, in which a plurality of types of filter characteristics are realized by changing the filter coefficient of a single filter circuit by time division. Is shown. In the figure, 41
b is a filter unit, FM is a frame memory (FIFO, etc.) capable of storing received radar pulses (for one burst), SW
1 is a switch for switching the signal input to the FIR filter, FM1 to FM2N are filter memories for accumulating and holding intermediate calculation results of each stage of the FIR filter, FWM is a filter coefficient memory storing a plurality of types of filter coefficient vectors, 41d is an adder for the outputs of FM1 to FM2N,
Reference numeral 2b denotes a maximum value detection unit that detects and holds the optimum filter characteristic that most closely matches the received radar pulse and that can sufficiently suppress the interfering reflected wave. Reference numeral 42d denotes each addition (convolution) of the filters F1 to F2N for a plurality of radar pulses. Arithmetic) A signal detection unit for obtaining an amplitude detection, a signal average value, a signal power or the like for an output signal, LTH is a latch circuit, SEL is a selector, and CMP is a comparison circuit.

Each of the filter memories FM1 to FM2N is a memory (RAM or the like) having a depth equal to or greater than a predetermined value (> 2N × pulse sample length). The reading / writing operation of the intermediate calculation result is performed under W. In the disturbance period, the FIR filter operates in the same manner as the FIR filter shown in FIG. 3B according to the optimum filter coefficient vector “w1 to w2N” detected in the disturbance preparation period in advance. Filter memories FM2 to FM2N are used, and these operate simply as delay circuits.

On the other hand, during the interference preparation period, 2N types of filter operations (partial operations) for a plurality of radar pulse inputs are efficiently performed in a time-division and time-series manner.
It operates as a memory having the depth of the pulse sample length. The details of the filter calculation method will be described later with reference to FIG.

FIG. 6 is an operation timing chart of the interference reflected wave suppression filter unit according to the second embodiment. Hereinafter, the operation from the interference preparation period to the interference period will be described with reference to FIG. In the disturbance preparation period, the FIR filter realizes 2N types of filter circuits F1 to F2N having taps of 2N sample length in a time division manner according to the filter coefficient vectors W (1) to W (2N) provided from the filter coefficient memory FWM. I do. Since the radar pulse is received only during the section of the reception gate length, one type of filter operation (partial operation) can be executed in a time substantially equivalent to the radar pulse width (data sample length). Therefore, the radar pulse repetition period PR
The duty ratio of one filter operation for I is 1 / 2N
If it is below, 2N kinds of filter operations can be executed within the time until the next radar pulse arrives.

When the receiving gate is opened, the switch SW1
Is connected to the terminal a, the first received radar pulse (the figure shows an example of four sample data p11 to p14) is input to the FIR filter, and the radar pulse is also stored in the frame memory FM. At this time, a filter coefficient selection signal C = 1 output from the control unit 35 via the selector SEL3 in advance causes the filter coefficient memory F
From WM, a filter coefficient vector W (1) is read, whereby the FIR filter filters F1 for the first received radar pulse (data p11 to p14).
Is performed, and each multiplication result is stored in each of the filter memories FM1 to FM2N.

Next, the connection of the switch SW1 is switched to the terminal b, and thereafter, the radar pulse of the frame memory FM can be repeatedly input to the FIR filter. Further, in this state, the filter coefficient selection signal C of the control unit 35 becomes 2, whereby the FIR filter performs a partial operation on the received radar pulse as the filter F2, and stores each operation result in the filter memories FM1 to FM2N. . Thereafter, the process proceeds in the same manner, and finally, a partial operation is performed on the received radar pulse as the filter F2N, and the operation results are stored in the filter memories FM1 to FM2N.

Further, when the receiving gate is opened next time, the same processing as described above is performed for the second radar pulse, and the partial calculation and storage of the calculation result are repeated every time the required number of radar pulses are received.

Next, for example, each partial calculation result of the radar pulse relating to the filter F1 is read out in time series and added, and a radar pulse sample input (p11 to p in the figure) is input.
14, the output signal (convolution operation result) of the corresponding filter F1 is formed in time series, and the signal detection unit 42
Output to d. Next, the same processing as described above is performed on the radar pulse, and thus the filter output signals for all the radar pulses are generated in time series and output to the signal detection unit 42d.

The signal detector 42d processes the output signal of the filter F1 and latches the maximum value, the average value or the signal power of the signal amplitude in the latch LTH1. The comparator CMP1 compares the content A of the latch LTH1 with the content B of the maximum value holding latch LTH2 (initialized to 0), where A>
In the case of B, the latch enable signal EN = 1 is output, whereby the content of the latch LTH1 is changed to the maximum value holding latch LT.
Latched to H2. At the same time, the current filter coefficient selection signal C = 1 is latched in the latch LTH3.

Next, the maximum value of the output of the filter F2 is detected for all the radar pulses,..., And is compared with the output of the maximum value holding latch LTH2. Update the content. When the comparison / latch for all filter outputs is completed in this way, the latch LTH3 has all radar pulses,
,... Are retained.

In the disturbance period, the selector SEL3
Filter coefficient selection signal held by latch LTH3
(For example, n), the FIR filter performs a filter operation (convolution operation) as a normal FIR filter Fn in real time, and outputs an output signal y
Is output to the storage / playback unit 33.

FIG. 7 is a diagram for explaining the operation of the filter unit 41b according to the second embodiment, in which 4P-DFT (N = 2).
The operation at will be described specifically. In FIG. 7A, when the sample data p11 to p14 of the radar pulse is input, the filter outputs y11 to y17 are originally provided.
Is a convolution operation of the input sample data p11 to p14 and the filter coefficient vector W (1) as shown in the figure. At this point, all the filter operations are not performed, and the filter coefficient multiplication (w11p11 to w14p11, w1) of each stage is not performed.
1p12 to w14p12), and the multiplication results are stored in the filter memories FM1 to FM4. FIG. 7B
7 (d), the partial operations of the filters F2 to F4 are continuously performed, and the multiplication results are stored in the filter memories FM1 to FM4.

FIGS. 7 (e) to 7 (h) show the relationship between the convolution operation of the filters F1 to F4 and its partial operation with respect to the radar pulse, and in the same manner, the partial operation for the required number of radar pulses. Is performed, and each calculation result is stored in the filter memories FM1 to FM4.

Next, for example, the partial calculation results of the radar pulse relating to the filter F1 are read out in time series and added, and the output signals (convolution calculation results) y11 of the filter F1 corresponding to the input samples p11 to p14 of the radar pulse, respectively. To y17 are formed in time series, and the signal detection unit 42
Output to d. Next, the input sample p2 of the radar pulse
Output signals y21 of the filter F1 corresponding to 1 to p24, respectively.
Ｙy27 are formed in time series and output to the signal detection unit 42d. In the same manner, the output signal y of the filter F1 corresponding to the required number of input radar pulses is output to the signal detection unit 42d in time series. Filter F2 to F4
The same applies to.

In the above-described embodiment, all the input samples p11 to p14, p21 to p21 of each radar pulse,.
The output signals y of the filters F1 to F4 are generated based on p24,..., but are not limited thereto. For example, the output signals of the filters F1 to F4 may be generated based only on the first input samples p11, p21,... Of each radar pulse,.

FIG. 8 is a block diagram of a main part of a radio wave jamming device according to the second embodiment. Jamming is performed by subtracting a jamming reflected wave signal acquired in advance from a subsequent radar reception signal (radar wave + jamming reflected wave). The case where a reflected wave component is removed is shown. In the figure, reference numeral 50 denotes an interfering reflected wave storage / reproducing which receives and stores an interfering reflected wave signal in advance and reproduces the signal at the time of radar reception.
A reproduction unit 51 is a subtraction unit that subtracts the reproduced interference reflected wave signal from the radar reception signal (radar wave + interference reflected wave).

The control unit 35 generates a reflected wave sample gate signal substantially in the middle of the interfering wave transmission period, in addition to the reception gate signal, and rejects the interfering reflected wave sample received and acquired during this period. The information is stored in the storage / reproduction unit 50. Next, when the receiving gate is opened, the interference reflected wave component stored above is subtracted from the radar reception signal, thereby effectively removing the interference reflected wave component. Therefore, the interference wave can be transmitted until immediately before the reception gate is opened, and the interference effect increases. This will be described in detail below.

FIG. 9 is a block diagram of a radio wave jamming device according to the second embodiment. The control unit 35 includes a CPU 35
a, including a timing generation unit 35b including a counter / sequencer circuit and the like, and generates various timing / control signals based on analysis information (PRI, radar pulse width PW, etc.) of the radar device 10 in detail.

The interfering reflected wave storage / reproducing unit 50 includes a memory circuit such as a FIFO having a depth equal to or greater than the reflected wave sample gate length (> pulse sample length), and the control unit 35 operates during the period when the reflected wave sample gate is ON. The received signal (pure interfering reflected wave signal) in the reflected wave sample gate is written in the reflected wave memory in accordance with the reflected wave memory write control signal generated in the above. Further, during the subsequent reception gate ON period, the stored interfering reflected wave (reflected wave sample) is read from the reflected wave memory circuit in accordance with the reflected wave memory read control signal from the control unit 35.

The subtraction unit 51 is composed of a simple subtraction circuit, and removes the interference reflected wave component from the radar reception signal during the reception gate ON period by subtracting the interference reflected wave signal of the reflected wave memory. A radar pulse signal is generated, and this signal becomes a source of the next generation of the interference wave.

FIG. 10 is an operation timing chart of the radio wave jamming device according to the second embodiment. The control unit 35
First, a radar reception signal detection operation is performed prior to the start of interference, and when a target signal (enemy radar pulse) is locked on, a reception gate generation counter circuit (not shown) is started based on the timing of the radar pulse detection edge. . The reception gate generation counter circuit calculates the time Td = PRI−Tgate (where Tga
te: reception gate length), the reception gate is turned on, and is turned off after a lapse of time Tgate. The control unit 35
Activates the counter circuit (not shown) for the reflected wave sample gate simultaneously with the activation of the reception gate generation counter circuit. The counter circuit for the reflected wave sample gate
The reflected wave sample gate is turned on after a lapse of about half the time Tds when the reception gate is turned on, and is turned off after a predetermined time (@Tgate).

In the second embodiment, it is important that there is a strong correlation between the previously acquired interference reflected wave sample waveform and the interference reflected wave waveform superimposed and input when the radar pulse is received. In the case of, the interfering reflected wave component can be completely removed. Therefore, in order to obtain this strong correlation, the generation timing Tds of the reflected wave sample gate is controlled as follows.

Tds = Td−n × PWr where PWr: reproduction pulse width (≒ PW) n: an integer that satisfies, for example, (PRI−Tgate) / 2PWr This timing relationship will be specifically described with reference to FIG. . In this example, the period during which the reception gate S2 is ON (= 3P
Wr), a radar reception signal (radar wave + interference reflected wave) is received.
The reflected wave sample gate is ON only for the period of PWr, and the pure interfering reflected wave sample received during this period is stored in the reflected wave memory.

The interfering reflected wave waveform received and stored at this time is a reflected wave waveform of a series of interfering waves transmitted immediately before the reflected wave sample gate is opened. There is a strong correlation between the reflected wave waveforms of a series of interfering waves transmitted under the same conditions (such as the time phase). Therefore, the interfering reflected wave input when the reception gate is ON is the immediately preceding reflected wave sample gate ON. The waveform, amplitude, and phase of the interfering reflected wave that are sometimes input are substantially the same.

Preferably, in order to easily and surely realize the above-described timing control, the operation of reproducing the radar pulse waveform in the storage / reproduction unit 33 is continued even while the reflected wave sample gate is open. Do. This makes it possible to easily and reliably generate and maintain the generation timing of the reflected wave sample gate (for 3PWr) and its ON period.
However, no interfering wave is transmitted in this section.

Further, in order to turn on the reception gate a little before the arrival prediction timing in consideration of the arrival prediction error of the radar pulse, the reception gate is turned on at the same time as the reception gate is turned on. The interference reflected wave with the same waveform as the acquired interference wave sample starts to be received,
Thereafter, the radar pulse wave is superimposed and received. Therefore, the interference reflected wave component can be effectively removed by subtracting the interference wave sample waveform from the reception wave at the same time when the reception gate is turned ON.

When the reception gate is turned off, only a necessary portion (for the reproduction pulse width PWr) of the reception signal stored in the memory circuit 33b of the storage / reproduction unit 33 is cut out, read out and reproduced. Until the next reception gate is turned ON, the reproduction operation is repeatedly performed. After Doppler modulation is performed by the Doppler modulation unit 34, the signal is amplified by the transmission / reception unit 32, and the enemy is transmitted from the antenna 31 as an interference wave. The data is transmitted to the radar device 10.

Incidentally, in this type of radio wave jamming device, there is a radio wave jamming device in which a non-linear amplifier circuit such as a limiter amplifier (limiting amplifier) is provided in a reception system in order to keep a radar reception signal at a constant level. However, if the receiving system has a limiter amplifier, the limiter amplifier is used to receive the interfering reflected wave signal alone when the reflected wave sample gate is ON and to receive the radar received signal (radar wave + interfering reflected wave) when the receiving gate is ON. Since the output amplitude of the signal is always constant, if the pre-stored interfering reflected wave sample is subtracted from the radar reception signal as it is, the amplitude differs between the two interfering reflected wave signals, and the interfering reflected wave component can be effectively canceled. Absent.

FIG. 11 is a block diagram of a main part of a radio wave jamming device according to the third embodiment, which is suitably applied to a device having a nonlinear amplification circuit such as a limiter amplifier in a receiving system.
In FIG. 11A, LA is a limiter amplifier, 60 is a level correction unit, and other configurations may be the same as those described with reference to FIG.

In the figure, the output amplitude of the limiter amplifier LA is always constant (for example, 1). First, when an interfering reflected wave is received independently, the amplitude of the interfering reflected wave signal is 1, and this is used as an interfering reflected wave sample to store the interfering reflected wave.
The information is stored in the reproducing unit 50. Next, when the receiving gate is turned on,
In this section, the interfering reflected wave is superimposed on the original radar pulse. At this time, the output amplitude of the limiter amplifier LA is also 1, but the signal distribution is, for example, radar pulse component = 0.5, interfering reflected wave component = 0. .5. Even if the stored interference reflected wave sample signal (amplitude = 1) is subtracted from the radar reception signal, the interference reflection wave component (amplitude = 0.5) of the radar reception signal cannot be effectively canceled. Therefore,
When the amplitude of the radar reception signal is doubled by the level correction unit 60, the signal distribution becomes radar pulse component = 1, disturbing reflected wave component = 1, and the disturbing reflected wave component = 1 is the stored disturbing reflected wave sample. It is effectively canceled by the signal (amplitude = 1). Further, in this example, since the amplitude of the remaining radar pulse component is 1 (required), it can be used as it is as a radar pulse signal for generating an interference wave. Therefore, according to the third embodiment, even if a non-linear amplifier circuit such as a limi amplifier is provided in the radar pulse receiving system, an interfering reflected wave component is obtained from the radar reception signal (radar wave + interfering reflected wave). It can be effectively removed, so that a number of effective interference waves can be transmitted until immediately before the reception gate is opened, and the interference effect can be greatly increased.

FIG. 12 is a block diagram of a radio wave jamming device according to the third embodiment. Two levels of received signals are input from the transmission / reception unit 32 to the level correction unit 60. One of the received signals (non-linear signals) from the output of the limiter amplifier LA is input to the interference reflected wave storage / reproduction unit 50, where the storage / reproduction is performed.
It is reproduced and input to one of the subtraction units 51, and the other is subjected to level correction by the multiplier 69 of the level correction unit 60,
The signal is input to the other side of the subtraction unit 51.

On the other hand, the received signal (linear signal) from the preceding stage of the limiter amplifier LA is subjected to amplitude detection by the amplitude detection circuit 61, and the detection output is input to the radar wave level latch circuit 62 and the reflected wave level latch circuit 63. The radar wave level latch circuit 62 latches the amplitude detection value Lr of the radar wave that does not include the disturbing reflected wave component at a substantially central timing during the reception gate ON period, and the reflected wave level latch circuit 63 operates as a reflected wave sample gate. The amplitude detection value Ls of the interfering reflected wave is latched at a substantially central timing during the ON period. The two-level signals Lr and Ls are input to a level correction circuit 64, added (Lr + Ls) by an adder 65, and then multiplied by a predetermined number (for example, 1 / Th) by a multiplier 66. K0 = (Lr + Ls) /
It is held as Th. Here, Th is the limiter amplifier L
The threshold value of A. The correction coefficient K0 = (Lr + Ls) / Th and K = 1 are input to the selector circuit 68, and these are switched according to the selection signal from the selection signal generator 70.

The selection signal generator 70 generates a selection signal for the correction coefficient K / K0 by detecting the start (rising) edge and the end (falling) edge of the radar pulse waveform. That is, the output signal of the subtracting unit 51 is differentiated by the differentiating circuit 71, and the differentiated output is threshold-determined by the threshold detecting circuit 71. According to the threshold-determining result, the correction coefficient K0 = (Lr + Ls) / during the arrival period of the radar pulse. T
h, a selection signal for selecting the correction coefficient K = 1 in other periods is generated. Hereinafter, this correction operation will be described.

Since the interval of the reception gate ON is longer than the arriving radar pulse width TW, the first arrival when the reception gate is ON is an interfering reflected wave. At this time, the correction coefficient K =
When 1 is selected, the signal level of the reproduced interference reflected wave from the interference reflected wave storage / reproducing unit 50 and the received interference reflected wave are matched by the operation of the limiter amplifier LA. The level is $ 0.

In this state, when a radar pulse arrives,
At this time, as a result of the radar pulse being superimposed on the interfering reflected wave, the signal level (amplitude) of the received interfering reflected wave component relatively decreases due to the operation of the limiter amplifier LA. At this time, a significant signal (mainly a radar wave component) appears in the output of the subtraction unit 51, and its rising edge can be detected. If the correction coefficient K0 = (Lr + Ls) / Th is selected at this time, it is possible to match the level (amplitude) of the reproduced interfering reflected wave from the interfering reflected wave storage / reproducing unit 50 with the received interfering reflected wave component. Thus, the reception interference reflected wave component can be effectively removed. At this time, the subtraction unit 51
, Only pure radar wave components are obtained.

In this state, when the reception radar pulse is completed, only the interfering reflected wave is received thereafter. As a result, the level of the interfering reflected wave is reduced by the operation of the limiter amplifier LA.
(Amplitude) rises relatively. At this time, a significant change in the signal level appears in the output of the subtraction unit 51, and by catching this change, the end (fall) of the radar pulse waveform is obtained.
Detect edges. It should be noted that the accuracy and reliability can be increased by using information of the known radar pulse pulse width TW for detecting the falling edge. Further, the threshold (sensitivity) of the threshold detection circuit 72 may be changed between the detection of the rising edge and the detection of the falling edge of the radar pulse waveform.

At this time, by selecting the correction coefficient K = 1 again, the reproduced interference reflected wave from the interference reflected wave storage / reproducing unit 50 and the bell of the received interference reflected wave thereafter match. Therefore, the output signal level of the subtraction unit 51 ≒ 0
Becomes Thus, a pure radar wave signal can be effectively extracted regardless of the superposition of the interfering reflected wave on the radar pulse.

It is generally considered that the coefficient K0 is calculated by periodically acquiring the amplitude detection values Lr and Ls from the actual received signal. For this purpose, as shown in FIG. It is necessary to separately input the received signal at the previous stage of the non-linear circuit such as the limiter amplifier LA in the receiving unit 32 to the level correction unit 60. In this case, the transmission / reception unit 32 switches to time division for output and
There are cases where two systems are output in parallel. Further, depending on the contents of the system design, a fixed value of the coefficient K0 may be obtained in advance as a design value.

The level correction circuit 64 described above
Represents an adder 65, multipliers 66 and 69, a selector circuit 68
And so on, but the actual level correction circuit 64
Can replace these operations with a ROM or the like in which a conversion table is formed.

In FIG. 11A, the level correction unit 60 is provided in the radar reception signal system. However, the present invention is not limited to this.
For example, as shown in FIG. 11 (B), the level correction unit 60 may be inserted into the system of the interfering reflected wave storage / reproduction unit 50 (before or after). In this case, since the output of the subtraction unit 51 is 1 / K0 in the case of FIG. 11A, a second level correction unit 60 'for increasing the output K times again is provided. The level correction unit 60 ′ can insert any part 2 of the route from the subtraction unit 51 to the transmission / reception unit 32 around the storage / reproduction unit 33. Therefore, the portion of the signal level (amplitude) affected by adopting the configuration of FIG. 11B can be effectively canceled by the second level correction unit 60 ′.

Incidentally, the polarization plane of the antenna 31 ′ in the conventional radio wave jamming device 30 ′ is different from that of the counterpart radar device 10 ′.
, For example, when the antenna is V-polarized,
Of the transmission / reception antenna 31 ′ of the V-polarized wave. This was intended to eliminate the polarization loss between the antenna of the radar device 10 and the transmitting and receiving antennas 31 'of the radio wave jamming device 30'. However, for this reason, interference between the original radar pulse and the interfering reflected wave has been inevitable.

FIG. 13 is a block diagram of a main part of a radio wave jamming device according to the fourth embodiment, in which a transmitting system for jamming waves and a receiving system for radar pulse signals are provided so as to be orthogonal to each other in terms of polarization. Shows the case. Other configurations may be the same as those described with reference to FIG. Here, the type of the antenna 31 may be a parabolic antenna, a horn antenna, or the like.

In FIG. 13, the antenna 31 maintains the polarization plane isolation (orthogonality) between the transmitting antenna 31 a and the receiving antenna 31 b while maintaining the antenna of the radar device 10 and the radio wave jamming device 30. The transmission antenna 31a and the reception antenna 31b have both polarization planes so that the polarization loss between the transmission / reception antennas 31 is equal.

For example, when the antenna of the counterpart radar device 10 is V-polarized, the receiving antenna 31b is polarized at +45 degrees and the transmitting antenna 31a is polarized at -45 degrees, so that the antenna of the radar device 10 and the Polarization loss (3 dB loss) between transmitting / receiving antennas 31a and 31b of device 30
And transmission / reception antennas 31a, 31b
Between them, polarization isolation is provided. As a result, only the interference reflected wave component can be effectively removed from the radar reception signal (radar wave + interference reflected wave).
The interference wave can be transmitted until just before the reception gate is opened, and the interference effect can be greatly increased.

FIG. 14 is a block diagram of a radio wave jamming device according to the fourth embodiment. In the figure, when the antenna polarization plane of the counterpart radar device 10 is V-polarized, the electric field differs by + 45 ° when the radio wave jammer 30 receives the signal with the + 45 ° polarized reception antenna 31b.
dB. Similarly, when the interfering device transmits the interfering wave with the transmitting antenna 31a of -45 ° polarization, the radar device 10
Since the antenna polarization plane is V-polarized, the polarization loss is 3 dB, and the polarization losses are equal.

The polarization loss between the transmitting / receiving antennas 31a and 31b is ideally infinite because the direction of the electric field differs by exactly 90 °. Therefore, in the receiving antenna 31b in which the polarization loss is infinite with respect to the interfering reflected wave having the same polarization as the transmitting interfering wave, the interfering reflected wave is not received at all, and as a result, the interfering reflected wave component is Can be effectively removed.

The polarization plane of the radar device 10 is not limited to the V polarization. FIG. 15 shows a correspondence relationship between various polarization planes that the radar apparatus 10 can adopt and the polarization planes of the radio wave jammer 30 that deal with the various polarization planes. For each of the V polarization, H polarization, right circular polarization, and left circular polarization that the radar device 10 in the left column can adopt, the respective polarization configurations that the antennas 31a and 31b of the radio wave jamming device 30 can adopt are described. It is shown in the right column. Conversely, if the respective polarization planes of the receiving / transmitting antennas 31b and 31a are set to V polarization / H polarization or H polarization / V polarization, the radar apparatus 10 will be able to perform right circular polarization, left circular polarization, and +45 polarization. It is possible to cope with each case of the polarization of ° and the polarization of −45 °. Similarly, receiving / transmitting antennas 31b, 31a
If the plane of polarization is right / left circular polarization or left / right circular polarization, the radar apparatus 10 will be able to provide V polarization, H polarization, + 45 ° polarization, −4
Each case of 5 ° polarization can be handled. Even in these cases, the type of antenna may be a parabolic antenna, a horn antenna, or the like.

When the polarization of the radar device 10 is plural or changed, the radio wave interference device 3 is adjusted accordingly.
It is necessary to change the polarization plane of zero.

In FIG. 14, in this case, the polarization information of the radar apparatus 10 is separately obtained as analysis information from the analysis apparatus 100, and the antenna rotation mechanism 31c for switching (changing) the polarization plane is used. Will be added.

For example, when the receiving / transmitting antennas 31b and 31a are respectively configured with −45 ° / + 45 ° polarization, the polarization of the radar device 10 that cannot be directly handled is + 45 ° / + 45 °.
Although only the −45 ° polarization is used, if the transmission antenna 31a and the reception antenna 31b are both rotated by 45 °, the transmission / reception antennas 31a and 31b become V polarization and H polarization. Can respond to.

Although the above embodiments have been described with specific numerical examples, the present invention is not limited to these numerical examples.

Although a plurality of embodiments suitable for the present invention have been described, it can be said that various changes can be made in the configuration, control, processing, and combinations thereof without departing from the spirit of the present invention. Not even.

For example, by using any one of the characteristic configurations described in the first to third embodiments in combination with the radio wave jamming device according to the fourth embodiment, the effect of suppressing the interfering reflected waves can be reduced. It can be more reliable. Various other combinations are also conceivable.

(Supplementary Note 1) In a radio wave jammer of a system in which a radar pulse signal of a partner is received and stored, a Doppler modulation is applied to the signal to generate a jamming wave, and the wave is continuously bounced back to the partner, a repetition frequency of the received radar pulse is used. A filter unit that realizes a plurality of types of filters that match the reception radar pulse based on each information of the Doppler modulation frequency set by the user and that can suppress the reflected wave signal of the interference wave transmitted by the user; A maximum value detection unit that detects a filter that most closely matches a received radar pulse based on each output obtained by passing a pulse through a plurality of types of filters; and stores and reproduces a radar pulse signal of the detected filter output for generating an interference wave. A radio wave jammer comprising a storage / reproducing unit.

(Supplementary Note 2) An interference preparation period for detecting a filter that most closely matches the received radar pulse, and a radar pulse signal of the detected filter output is stored and reproduced to generate an interference wave, which is continuously transmitted to the other party. 2. The radio wave jamming device according to claim 1, wherein the jamming period for returning is alternately provided. Therefore, the radar pulse data (f
r, PRI, etc.) can be quickly and accurately followed even if they are changed arbitrarily.

(Supplementary Note 3) In the radio wave jammer of the system of receiving and storing the radar pulse signal of the other party, applying Doppler modulation thereto to generate an interference wave, and continuously returning the same to the other party, the interference wave transmitted immediately before Receiving and storing the reflected wave signal, and retrieving / reproducing an interfering reflected wave signal which can be reproduced at the time of receiving a subsequent radar pulse, and a subtracting unit for subtracting the stored / reproduced interfering reflected wave signal from the received radar pulse signal. And a storage / reproducing unit for storing and reproducing a radar pulse signal output from the subtracting unit for generating an interfering wave.

(Supplementary Note 4) The interfering reflected wave sample period for receiving and storing the reflected wave signal of the interfering wave transmitted immediately before is provided at a substantially intermediate portion of the interfering wave transmitting period which is developed until immediately before the reception gate is opened. The radio wave jamming device according to claim 3, characterized in that:

In appendix (4), first, the reflected wave signal of the interfering wave transmitted substantially at the middle of the interfering wave transmission period is received and sampled for a predetermined interfering reflected wave sample period (≒ receiving gate length), and this is intercepted. It is stored in the reflected wave storage / reproduction unit 50. Preferably, the transmission of the interfering wave during the interfering reflected wave sample period is performed so that the reflected wave environment of the interfering wave during the interfering reflected wave sample period and the reflected wave environment of the interfering wave when the reception gate is turned on match. Stop it. In the subsequent reception gate ON section, the reflected wave of the interference wave transmitted immediately before the reception gate ON arrives superimposed on the original radar pulse in the same manner as during the interference reflection wave sampling period. From the signal (radar wave + interfering reflected wave), the interfering reflected wave component can be effectively removed by using the interfering reflected wave sample obtained in the same interfering wave environment as described above.

(Supplementary Note 5) In a radio wave jammer of a system that receives and stores a radar pulse signal of the other party via a non-linear amplifier, performs Doppler modulation on the received radar pulse signal, generates an interference wave, and continuously bounces back to the other party. An interfering reflected wave storage / reproducing unit capable of receiving and storing a reflected wave signal of an immediately transmitted interfering wave and reproducing the same when receiving a subsequent radar pulse, and a level for correcting the amplitude and / or level of the received radar pulse signal A correction unit, and a subtraction unit that subtracts the stored and reproduced interference reflected wave signal from the corrected radar pulse signal,
A radio wave jammer comprising: a storage / reproducing unit that stores and reproduces a radar pulse signal output from the subtracting unit for generating an interference wave.

In FIG. 11A, the non-linear amplifier LA
Is always constant (for example, 1). First, when an interfering reflected wave is received alone, the amplitude of the interfering reflected wave signal is 1, and this is stored in the interfering reflected wave storage / reproducing unit 50 as an interfering reflected wave sample. Next, reception gate is ON
Then, in this section, the interfering reflected wave is superimposed on the original radar pulse. At this time, the output amplitude of the non-linear amplifier LA is also 1, but the signal distribution is, for example, radar pulse component = 0.5, Wave component = 0.5. Even if the stored interfering reflected wave sample signal (amplitude = 1) is subtracted from the radar received signal, the interfering reflected wave component (amplitude = 0.5) of the radar received signal cannot be effectively canceled.
Therefore, the amplitude of the radar reception signal is converted to the level correction unit 60.
And the signal distribution becomes radar pulse component =
1, the interference reflected wave component = 1, and this interference reflected wave component =
1 is the stored interference reflected wave sample signal (amplitude = 1)
Is effectively offset by Further, in this example, since the amplitude of the remaining radar pulse component is 1 (required), it can be used as it is as a radar pulse signal for generating an interference wave. Therefore, according to Appendix (5), even if the radar pulse receiving system includes a non-linear amplifier circuit such as a limiter amplifier, the reflected interference wave component is effectively removed from the radar reception signal (radar wave + interference reflected wave). Therefore, a number of effective interference waves can be transmitted until immediately before the reception gate is opened, and the interference effect can be greatly increased.

(Supplementary Note 6) In a radio wave jammer of a system of receiving and storing a radar pulse signal of the other party through a non-linear amplifier, applying Doppler modulation to the signal and generating an interfering wave, and continuously returning the same to the other party. An interfering reflected wave storage / reproducing unit that receives and stores a reflected wave signal of an interfering wave transmitted immediately before, and that can reproduce the received reflected wave signal when receiving a subsequent radar pulse; and an interfering reflected wave stored and reproduced from the received radar pulse signal. A subtraction unit for subtracting a wave signal; a storage / reproduction unit for storing and reproducing a radar pulse signal output from the subtraction unit for generating an interference wave; and a level provided before or after the interference reflection wave storage / reproduction unit. A correction unit for correcting the amplitude and / or the level of the received interference reflected wave signal.

In FIG. 11 (B), due to the operation of the level correction section 60 described in the above supplementary note (5), this level correction section 60 becomes the interference reflected wave storage / reproduction section 5 as shown in the supplementary note (6).
Obviously, it may be provided before or after the zero.

(Supplementary Note 7) A second level correction unit provided at a stage subsequent to the subtraction unit, the second level correction unit correcting the amplitude and / or the level of a radar pulse signal which is an interference wave or its source. 7. The radio wave jamming device according to claim 5, wherein

The amplitude of the remaining radar pulse component is 1 depending on the arrangement of the level correction unit 60 described in the appendixes (5) and (6) or the level correction value of the level correction unit 60.
It may not be (required). Therefore, a second level correction unit 60 'is provided downstream of the subtraction unit 51, and corrects the amplitude and / or level of the interfering wave or the radar pulse signal that is the source of the interference wave to a required level. Therefore, the above additional statement (5)
Alternatively, the portion of the signal level (amplitude) affected by adopting the configuration of (6) is converted to the second level corrector 60 ′.
Can be effectively offset by

(Supplementary Note 8) Receive and store the radar pulse signal of the other party, apply Doppler modulation to this signal to generate an interfering wave, and receive the radar pulse in a radio wave jammer of a system that continuously returns to the other party. A radio wave jammer comprising a system antenna and a transmission system antenna for transmitting an interfering wave provided such that their polarization planes are orthogonal to each other.

(Supplementary note 9) The radio interference described in Supplementary note (8), wherein both the polarization planes of the reception system antenna and the transmission system antenna are rotatable while maintaining the orthogonal relationship. apparatus. Therefore, regardless of the polarization plane used by the other radar apparatus, both polarization planes of the radio wave jamming apparatus can be appropriately rotated in accordance with the polarization plane, so that a large interference effect can be always exerted.

[0098]

As described above, according to the present invention, a number of effective interference waves can be transmitted until immediately before the reception gate for receiving the radar pulse is opened, so that the interference effect is significantly increased.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of a radio wave jamming device according to a first embodiment.

FIG. 2 is a diagram illustrating a principle of suppressing a reflected interference wave by a filter.

FIG. 3 is a diagram illustrating an interference reflected wave suppression filter unit according to the first embodiment.

FIG. 4 is a diagram illustrating an example of a filter characteristic by 4P-DFT.

FIG. 5 is a block diagram of an interference reflected wave suppression filter unit according to a second embodiment.

FIG. 6 is an operation timing chart of the reflected wave suppression filter according to the second embodiment.

FIG. 7 is a diagram illustrating an operation of a filter unit according to a second embodiment.

FIG. 8 is a main part configuration diagram of a radio wave jamming device according to a second embodiment.

FIG. 9 is a block diagram of a radio wave jamming device according to a second embodiment.

FIG. 10 is an operation timing chart of the radio wave jamming device according to the second embodiment.

FIG. 11 is a main part configuration diagram of a radio wave jamming device according to a third embodiment.

FIG. 12 is a block diagram of a radio interference device according to a third embodiment.

FIG. 13 is a main part configuration diagram of a radio wave interference device according to a fourth embodiment.

FIG. 14 is a block diagram of a radio interference device according to a fourth embodiment.

FIG. 15 is a diagram showing combinations of polarization planes according to the fourth embodiment.

FIG. 16 is a diagram (1) illustrating a conventional technique.

FIG. 17 is a diagram (2) illustrating a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 30 radio wave jammer 31 antenna 32 transmission / reception unit 40 interference reflection wave suppression filter unit 41 filter unit 42 maximum value detection unit 33 storage / reproduction unit 34 Doppler modulation unit 35 control unit 50 interference reflection wave storage / reproduction unit 51 subtraction unit 60 Level correction unit 100 analyzer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kashima Akira 4-1-1 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Yoshiharu Ueda 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. 1 Within Fujitsu Limited (72) Inventor Tadashi Fujimoto 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term within Fujitsu Limited (reference) 5J070 AB01 AD01 AD17 AD17 AH39 BH12

Claims (3)

[Claims] An apparatus for receiving and storing a radar pulse signal of a counterpart, applying Doppler modulation to the received radar pulse signal to generate an interfering wave, and continuously returning the interfering wave to the counterpart, wherein a repetition frequency of the received radar pulse and a self-pulse A filter unit that realizes a plurality of types of filters that match the reception radar pulse based on the information of the Doppler modulation frequency set by the user and that can suppress the reflected wave signal of the interference wave transmitted by the filter unit; and A maximum value detection unit that detects a filter that most closely matches a received radar pulse based on each output that has passed through a plurality of types of filters; and a storage unit that stores and reproduces the detected radar output pulse signal of the filter output for generating an interference wave. A radio wave jamming device comprising a reproducing unit. 2. A radio wave jammer of a system that receives and stores a radar pulse signal of the other party, performs Doppler modulation on the received radar pulse signal, generates an interference wave, and continuously bounces back to the other party, and reflects the interference wave transmitted immediately before. An interfering reflected wave storage / reproducing unit capable of receiving and storing a wave signal and reproducing the same when a subsequent radar pulse is received; a subtractor for subtracting the stored / reproduced interfering reflected wave signal from the received radar pulse signal; A radio wave jamming device comprising: a storage / playback unit that stores and reproduces a radar pulse signal output from a subtraction unit for generating a jamming wave. 3. A receiving antenna for receiving a radar pulse in a radio wave jammer of a system that receives and stores a radar pulse signal of the other party, performs Doppler modulation on the radar signal, generates an interfering wave, and continuously bounces back to the other party. And a transmitting antenna for transmitting the interfering wave provided so that their polarization planes are orthogonal to each other.