JP2667637B2 - Radar / target wave simulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a performance test of a radar having various existing functions, and a radar target wave is simulated by generating a radar target wave for each function of the test radar. The present invention relates to a radar / target wave simulating apparatus for transmitting to a target.

[0002]

2. Description of the Related Art In a conventional radar / target wave simulator, as shown in FIG. 3, an interface circuit 2 is mounted on a test radar 1 to be subjected to a performance test. COHO (Co
The abbreviation for herent oscillator means a signal having the same frequency as the intermediate frequency of the radar.) A signal A, a radar pulse reference signal B, and a local signal C for frequency conversion are extracted.

[0003] The COHO signal A is directly supplied to the pulse modulating unit 4.
Sent to Further, the radar pulse reference signal B is delayed by the pulse delay unit 3 based on the distance delay data D, and sent to the pulse modulation unit 4 as a pulse modulation trigger signal E.

The pulse modulator 4 fetches the COHO signal A each time the trigger signal E is supplied, and based on the known information of the radar under test 1, sets the pulse width of the target echo and the chirp, barker, etc. The modulation output F is sent to the frequency conversion unit 6.

On the other hand, the local signal C obtained by the interface circuit 2 is sent to a Doppler modulator 5. The Doppler modulator 5 simulates the Doppler shift of the target by modulating the local signal C with the Doppler signal G, and the simulated output is sent to the frequency converter 6 as the up-conversion local signal H.

The frequency conversion unit 6 converts the pulse modulation signal F into an RF signal using the local signal H to which the Doppler signal is added.
The signal is up-converted to a (high-frequency) signal I, and the converted output is sent to the power control unit 7.

The power control unit 7 simulates the radar target signal K by controlling the power of the high-frequency signal I in accordance with the power control data J based on the distance to the target. 8 sent to
It is radiated to the test radar 1 as a radar target wave. In this way, the test radar 1 receives the radar target wave from the transmission antenna unit 8 and performs signal processing, thereby performing a target echo simulation test for the own transmission radar wave.

However, the conventional radar / target simulator as described above has various problems as described below. First, a COHO signal, a local oscillation signal, and a radar pulse reference signal are supplied via a cable in order to generate a radar target wave of the same frequency as that of the test radar, and to further correspond to the transmission timing of the test radar. I have to get it.

Further, in order to input these signals, it is necessary to manufacture an interface circuit according to the radar under test. Further, for a test radar that performs intra-pulse modulation such as chirp or barker, it is necessary to input modulation method information in advance.

[0010]

As described above, in the conventional radar / target wave simulator, it is necessary to directly receive a COHO signal, a local oscillation signal, a radar pulse reference signal, and the like from the test radar. It was necessary to input information on the modulation method of the test radar in advance.

The present invention has been made to solve the above problems, and it is not necessary to receive signals and information from the test radar, and the radar target wave can be simulated and generated completely independently of the test radar. It is an object of the present invention to provide a radar / target wave simulator capable of performing the following.

[0012]

A radar according to the present invention is provided.
The target wave simulation device includes a reception antenna section that receives a radar wave transmitted from a radar under test, a quadrature demodulation section that demodulates a quadrature video signal from a radar wave reception signal obtained by the reception antenna section, and a quadrature demodulation section. Delay processing means for delaying the orthogonal video signal demodulated by the unit by a time corresponding to a relative distance between the test radar and the pseudo target,
Doppler modulation means for modulating the quadrature video signal at a Doppler frequency corresponding to the relative speed between the test radar and the pseudo target, up to a power intensity corresponding to the relative distance between the test radar and the pseudo target. A signal processing unit that includes a power control unit that reduces the signal, and that executes each unit in an arbitrary order and selectively to generate a radar target signal, and a radar target signal that is generated by this signal processing unit. A radar target wave simulation apparatus comprising a transmission antenna section for transmitting to the sample radar as a target wave, wherein the delay processing means includes I and Q signals of orthogonal video signals demodulated by the orthogonal demodulation section, respectively. An analog-to-digital converter that digitizes and converts to waveform data, and the analog-to-digital converter A memory circuit for writing / reading out the input I / Q signal waveform data, and a digital / analog conversion circuit for returning the I / Q signal waveform data output from the memory circuit to analog signals, respectively; The memory circuit is provided with a memory control circuit for controlling a time interval from a write timing to a read timing based on relative distance information between the test radar and the pseudo target.

[0013]

In the radar / target wave simulator having the above configuration, a pair of orthogonal video signals is demodulated with respect to the radar wave reception signal from the test radar obtained by the reception antenna unit.
This orthogonal video signal is modulated at the Doppler frequency corresponding to the relative speed between the sample radar and the pseudo target, delayed by the time corresponding to the relative distance, and further the power intensity corresponding to the relative distance between the sample radar and the pseudo target. Thus, a radar target signal is simulated and generated, and this radar target signal is transmitted to the test radar as a radar target wave. At this time, I,
Each Q signal is digitized, converted into waveform data, written into a memory circuit, read at an arbitrary timing, and returned to an analog signal. Here, the distance between the pseudo target can be freely controlled by controlling the time interval from the write timing to the read timing based on the relative distance information between the test radar and the pseudo target with respect to the memory circuit.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a basic configuration of a radar / target wave simulator according to the present invention. In FIG. 1, reference numeral 12 denotes a receiving antenna unit 12 for receiving a radar wave radiated from a test radar 11 to be subjected to a performance test. The radar wave reception signal a obtained by the reception antenna unit 12 is sent to the frequency conversion unit 13.

The frequency converter 13 includes a mixer 131 and a frequency-variable local oscillator 132 for generating a down-conversion local signal b. By mixing the radar wave reception signal a with the local signal b by the mixer 131, The received signal a is down-converted to an IF (intermediate frequency) signal. This IF signal is distributed to two systems by the signal distributor 14 and sent to the I / Q demodulator 15.

The I / Q demodulation unit 15 includes mixers 151 and 1
52, and the IF distributed by each of the mixers 151 and 152.
The signals generated by the I / Q modulation / demodulation oscillating section 16 are mutually 9
The I and Q video signals d and e are obtained by mixing frequency signals having a phase shift of 0 °. These I and Q video signals d,
e are both sent to the waveform storage unit 17.

As shown in FIG. 2, the waveform storage unit 17 stores the input I and Q video signals d and e in A / D
After being converted into digital signals by (analog / digital) converters 171 and 172, the signals are stored in a waveform storage memory 173. After a lapse of a predetermined time, the I and Q digital video signals stored in the memory 173 are read out, and the D / A converters 174 and 175 respectively read the original analog signals d and e.
Return to

The write / read control of the waveform storage memory 173 is performed by a memory controller 176. The time difference between the writing and reading of the memory controller 176 is determined by the delay controller 18.
Is determined by the delay data m. The delay control unit 18 outputs the target distance data p given from the outside.
To convert and output delay data m corresponding to the round trip time of a radar wave.

The I and Q video signals d and e delayed according to the target distance in the waveform storage unit 17 are sent to an I / Q modulation unit 19. The I / Q modulation section 19 includes a mixer 19
1 and 192, and the mixers 191 and 192 mix the I and Q video signals d and e with the frequency signals generated by the I / Q modulation / demodulation oscillator 16 and out of phase with each other by 90 °. The Q modulated signals f and g are obtained. These I and Q modulated signals f and g are combined in a signal combining unit 20, and the combined signal h is sent to a frequency conversion unit 21.

The frequency converter 21 includes a mixer 211 and a local oscillator 212 for generating a local signal i for up-conversion. The local signal i generated by the local oscillator 212 is supplied to the Doppler modulator 22. The Doppler converter 22 includes a modulator 221 and a Doppler signal generator 222. The Doppler signal generator 222 generates a Doppler signal j for simulating the Doppler shift of the target, and the modulator 221 converts the local signal i into a Doppler signal. Modulate by signal j. The local signal k that has been subjected to the Doppler modulation is sent to the mixer 211.

The frequency converter 21 uses the mixer 211 to output I,
By mixing the local signal k with the Q-modulated composite signal h,
At the same time that the composite signal h is up-converted into the RF signal l, the RF signal l has the target Doppler shift.

This RF signal 1 is sent to the power control unit 23. The power control unit 23 controls the transmission power of the RF signal 1 based on the power control data n based on the distance between the target and the test radar. The RF signal o generated in this manner is radiated from the transmission antenna unit 24 to the test radar 11 as a radar target wave.

That is, in the radar / target wave simulation apparatus having the above-mentioned structure, the radar wave radiated from the sample radar 11 is captured by the reception antenna section 12, and the received RF signal a is converted into the IF signal c by the frequency conversion section 11. After conversion, I
The I / Q video signals d and e are obtained by performing quadrature detection in the / Q demodulation unit 16. Then, these I / Q video signals d,
The waveform e is temporarily stored in the waveform storage unit 17, and is read out and output with a delay corresponding to the distance between the test radar 11 and the target.

Further, the read I / Q video signals f,
After synthesizing g, a Doppler shift characteristic of the target is given when up-converting by the frequency conversion unit 21, and the power of the converted RF signal 1 is controlled by the power control unit 23 according to the distance of the target or the like. The radar target signal is simulated and transmitted from the transmitting antenna unit 24 to the test radar 11 as a radar target wave.

The greatest feature of the present invention is that a radar wave is directly generated as a target wave by waveform storage, so that it can be used for almost all radars. In this waveform storage, I and Q video signals from the radar are stored after A / D conversion, and D / A conversion is performed after a necessary delay time has elapsed.
Since reproduction is performed as I and Q video signals, time, frequency, PRF changes frequency agility, multi-PR
A target wave simulation can be generated for a test radar having functions such as F.

Therefore, in the radar / target wave simulator having the above configuration, the radar wave from the test radar can be reproduced at high speed and faithfully by storing the waveform, so that the COHO signal, the local signal, and the like are received from the test radar. A radar target wave can be simulated without the need. Note that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented even if various changes are made without departing from the gist of the present invention.

[0027]

As described above, according to the present invention, it is not necessary to receive signals and information from the test radar, and it is possible to simulate the radar target wave independently of the test radar. -A target wave simulator can be provided. Particularly, in the delay processing means, the I and Q signal waveforms of the orthogonal video signal are converted into data, written in a memory circuit, read at a time difference corresponding to the relative distance between the sample radar and the simulated target, and restored to the original analog signal. , So that faithful radar waveform retransmission can be realized, and there is no restriction on the delay time simulation range, and any delay time (the relative distance between the test radar and the simulation target) can be simulated. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a radar / target wave simulator according to the present invention.

FIG. 2 is a block diagram illustrating a specific configuration of a waveform storage unit according to the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional radar / target wave simulator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test radar, 2 ... Interface circuit, 3 ... Pulse delay part, 4 ... Pulse modulation part, 5 ... Doppler modulation part,
6: frequency converter, 7: power controller, 8: transmitting antenna, A: COHO signal, B: radar pulse reference signal, C
... local signal, D ... distance delay data, E ... pulse modulation trigger signal, F ... pulse modulation signal, G ... Doppler signal, H ... local signal for upconversion, I ... R
F signal, J: power control data, K: radar target signal, 11: radar under test, 12: receiving antenna unit, 13
... frequency conversion unit, 131 ... mixer, 132 ... local oscillator, 14 ... signal distribution unit, 15 ... I / Q demodulation unit, 16 ... I
/ Q demodulation oscillation section, 17... Waveform storage section, 171, 172
... A / D converter, 173 ... waveform storage memory, 174,1
75 ... D / A converter, 176 ... Memory controller, 18 ... Delay control section, 19 ... I / Q modulation section, 191, 192 ... Mixer, 20 ... Signal combining section, 21 ... Frequency conversion section, 211 ...
Mixer, 212: Local oscillator, 22: Doppler modulator, 221: Modulator, 222: Doppler signal generator,
23: power control frequency conversion unit, 18: power control unit, 19:
Transmitting antenna section, 24: transmitting antenna section, a: radar wave reception signal, b: down conversion local signal,
c: IF signal, d: I video signal, e: Q video signal,
f ... I modulation signal, g ... Q modulation signal, h ... combined signal, i ...
Local signal for up-conversion, j: Doppler signal, k: Doppler modulated local signal, l: RF signal, m: delay data, n: power control data, o: radar target signal.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Eikichi Umekawa 1 Kosuka Toshiba-cho, Saisaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Komukai Plant (72) Inventor Masakazu Abe Komukai Toshiba, Sachi-ku, Kawasaki-shi, Kanagawa No. 1 in the town of Komukai Toshiba Corporation (56) References JP-A-4-315977 (JP, A) JP-A-57-22574 (JP, A) JP-A-4-203993 (JP, A) Hei 6-230108 (JP, A) Actual opening Hei 5-84882 (JP, U) Actual opening Hei 5-61700 (JP, U)

Claims (2)

(57) [Claims] 1. A receiving antenna section for receiving a radar wave transmitted from a radar under test, an orthogonal demodulation section for demodulating an orthogonal video signal from a radar wave reception signal obtained by the receiving antenna section, and an orthogonal demodulation section. For the quadrature video signal demodulated in
Delay processing means for delaying by a time corresponding to the relative distance between the test radar and the pseudo target, Doppler modulation means for modulating the orthogonal video signal at a Doppler frequency corresponding to the relative speed between the test radar and the pseudo target, A radar target signal is simulated by providing power control means for reducing the orthogonal video signal to a power intensity corresponding to the relative distance between the radar under test and the pseudo target, and selectively executing each means in an arbitrary order. A radar / target wave simulation device comprising: a signal processing unit for generating; and a transmission antenna unit for transmitting the radar / target signal generated by the signal processing unit to the sample radar as a radar / target wave, wherein the delay processing means Respectively digitizes the I and Q signals of the quadrature video signal demodulated by the quadrature demodulation unit and performs waveform decoding. An analog-to-digital conversion circuit for converting the data, I outputted from the analog-digital converter, Q
A memory circuit for writing / reading out the signal waveform data, a digital / analog conversion circuit for returning the I / Q signal waveform data output from the memory circuit to an analog signal and outputting the analog signal, A radar target wave simulation device, comprising: a memory control circuit for controlling a time interval from a write timing to a read timing based on relative distance information between the sample radar and the pseudo target. 2. The signal processing unit converts a radar wave reception signal obtained by the reception antenna unit into an intermediate frequency band, and performs processing of the delay processing unit and the Doppler modulation unit.
2. The radar / target wave simulating apparatus according to claim 1, wherein the processing is returned to the original frequency band and the processing of the power control means is performed.