JPH0222586A - radar equipment - Google Patents

Abstract

PURPOSE:To suppress the mixture of received signals between antennas and to reduce the scale of the device by modifying a pulse compression modulation system for a sent signal generator output signal of the same frequency. CONSTITUTION:A local oscillator is common among three 1st-3rd antenna systems. Then the pulse compression modulation system for the output signal of a sent signal generator of the same center frequency is modified. Consequently, even if the signal of, for example, the 2nd antenna system is mixed with the 1st antenna system, a pulse compression modulation system for each center frequency is different on a reception system, so the mixed signal is compressed by a pulse compressing filter. Then the local oscillator is used in common, so the device scale can be reduced.

Description

[Detailed Description of the Invention] [Field of Application on Tumors] This invention relates to a radar having a plurality of pulse radar antennas whose transmission signals are two types of composite signals, one for long distance and one for short distance, which are offset by one frequency. It is related to the device.

[Conventional technology]

In FIG. 2, (ia) is the first antenna,
(1b) is the second antenna, (1c) is the third antenna, (21 is the target, and QD is the building.

In a radar device having multiple antennas as shown in the second south, the transmitted wave from the antenna (1a) is reflected by the target (to) and returns to the antenna (1a).

It may be reflected by a building QD or the like, enter the antenna (1b), and be detected as a signal. In order to avoid such erroneous recognition, a plurality of local oscillators with different frequencies were used to provide different transmission signal frequencies. A block diagram of a conventional radar device is shown in FIG. IE3. In the figure, (l)
is an antenna, (21 is a circulator, (3) is a frequency converter, (4) is an IF amplifier, (5) is a distributor, (6)
is a pulse compression filter, and (7) is a detector.

(8) is a signal processor, (9) is a local oscillator, aα is a power amplifier, aD is a frequency converter, fl3 is a synthesizer, (1
3 is a frequency converter, (141 is a transmission signal generator, αS
is a pulse compression modulation generator, (le is a display device, and αn is a first antenna system.

Alternatively, α9 is the second antenna system and α9 is the third antenna system.

In the first antenna system, a first frequency modulation expansion produced by a first pulse compression modulation generator (tSa), a first transmission signal generator (t4a) and a first frequency converter (13a) A pulse signal and a second signal whose frequency is offset
The second frequency modulated expanded pulse signal generated by the pulse compression modulation generator (15b), the second transmission signal generator (14b) and the second frequency converter (13b) is transmitted to the first synthesizer ( 12a), frequency-converted by the fifth frequency converter (Ila) in response to the signal from the first local oscillator (9a), and power amplified by the first power amplifier (10a). It is radiated into the air through the first circulator (2a) and the first antenna (1a). Hit the target 1
What is the signal that becomes a reflected wave?

The 6Q frequency is transmitted through the first antenna (1a) and the first circulator (2a) as the receiving 1st signal, and the wave number converter (5
3), the signal from the first local oscillator (radiator (9a)) is frequency-converted and becomes an IF signal.This IF signal e is amplified by the first IF amplifier (4a) and then distributor (5
The first frequency f-adjusted expanded pulse No. 6 is divided into two by a), passes through the "th" pulse compression filter (6a), is detected by the first detector (7m), and becomes a video signal, and similarly , the second frequency modulated expanded pulse signal is passed through the second pulse compression filter (sb) f: A, detected by the second detector (7b), and is not converted into a video signal.
The signal is sent to the signal processor (8a).

The second antenna system is similar, but the first antenna (1
a*ci'f, the target reflected wave of the transmitted signal from the third antenna (1C) is due to multiple reflections, and the second antenna (1C)
b), it passes through the second circulator (2b) and enters the eighth frequency converter (3b). This eighth frequency converter (3b) has a bandpass filter corresponding to the frequency of the second local generator (9b), so the mixed signal is eliminated from the antenna system of @3. Similarly, if the target reflected wave of the transmitted signal from the first antenna (1a) or the second antenna (1b) mixes into the third antenna (1C) due to multiple reflections, the third circulator (2c) 1 and enters the tenth frequency converter (3c).This tenth frequency converter (3C)
has a bandpass filter corresponding to the frequency of the third local generator (9c), so the mixed signal is eliminated here.

[Problem to be solved by the invention]

Such conventional radar equipment with multiple antennas has 0
It had independent local oscillators with different frequencies, and the scale of the device was similar to that of an independent radar device.

The object of the present invention is to overcome the above-mentioned problems of the prior art.

[Means to solve the problem]

In the three antenna systems, the first antenna system, the second antenna system, and the third antenna system, the pulse width is different for long distance use and short distance use, but in order to distinguish between these, different frequencies are used. Transmit signal generator output signals (fl, f2 and r5
) is used here.

The local oscillator is common, and the output signal of the transmitting signal generator having the same center frequency (for example, the center frequency f
A configuration was adopted in which the pulse compression modulation method for 1) was changed.

[Effect]

With the above basic configuration, even if a signal from the second antenna system mixes into the ml antenna system, for example, the pulse compression modulation method for each center frequency is different in the receiving system.
The mixed signal is suppressed by a pulse compression filter. Furthermore, since one local oscillator is common, the scale of the device can be reduced.
The figure is a block diagram, with (1) to (8) and Q(1 to a
3. (14a), (14b), (14c), (
15g), (15b), (15c), ff
i is exactly the same as the above conventional device, and (9) is a local oscillator, the first transmission signal generator (14a) having a center frequency f1;
) to the first pulse compression modulation generator (15a)
(chirp with increasing frequency) and the first frequency modulation expansion pulse obtained by frequency converting the modulation signal from the center frequency f
3, the modulation signal from the second pulse compression modulation generator (15b) (chirp with decreasing frequency) is frequency-converted into the signal from the third transmission signal generator (14c).
The frequency modulated expanded pulses are synthesized by a first synthesizer (12a), and the signal received from the local oscillator (9) is frequency-converted by a fifth frequency converter (11a), and the signal is converted by a fal power amplifier (10g). The power is amplified by the first circulator (
2a) and is radiated into the air through the first antenna (1R). The signal that hits the target and becomes a reflected wave passes through the first antenna (1m) and the first circulator (2a) as a received signal, and is converted into a 6th frequency converter (3a) by the 6th frequency converter (3a).
The frequency is converted by the signal from the local oscillator (9) and the IF
It becomes a double signal. This IF' signal is transmitted to the first IF amplifier (4a
), the first frequency modulated expanded pulse is amplified by the first divider (!", , ), and the first frequency modulated expanded pulse passes through the first pulse compression filter (6a) and is amplified by the first detector (7a). ), the second frequency modulated expanded pulse passes through a second pulse compression filter (6b), is detected by a second detector (7b), and becomes a video signal, Sent to the first signal processor (8a). Center frequency f
A third frequency modulation expansion in which the modulation signal from the first pulse compression modulation generator (15m) (chirp with increasing frequency) is frequency-converted into a signal from the second transmission signal generator (14b) which is 2. pulse and the first transmit signal generator (1
4a) The same applies to the fourth frequency-modulated expansion pulse obtained by frequency-converting the modulation signal from the second pulse compression modulation generator (15b) (chirp with decreasing frequency) to the signal from (center frequency f1).

This becomes a video signal and is sent to the second signal processor (8b).

Third transmission signal generator (14c) (center frequency f5)
A first pulse compression modulation generator (15a) (
a fifth frequency-modulated expansion pulse obtained by frequency-converting a modulation signal from a chirp with increasing frequency;

Second transmission signal generator (14b) (center frequency f2)
A second pulse compression modulation generator (15b) (
Similarly, the sixth frequency modulated expansion pulse is sent to the third signal processor (8c) without converting it into a video signal. 1st
signal processor (8a% output and second signal processor (8b)
and the output of the third signal processor (8c) are displayed on the display device α.
displayed on G.

For example, if the transmission signal of the second antenna system mixes into the first antenna (1a), the first circulator (2a)
) at the sixth frequency converter (3a).

The frequency is converted by the signal from the local oscillator (9)! F
It becomes a double signal. This IF' signal is also transmitted to the first IF amplifier (4a
) and distributed by the first distributor (2a). Here, the modulation signal with center frequency f1 is input to the first pulse compression filter (6a), and the modulation signal with center frequency f3 is input to the second pulse compression filter (6b), but the modulation methods are different. for.

Both will be oppressed. In this way, misrecognition can be avoided.

〔Effect of the invention〕

As shown in Section 6 above, in a radar device having a plurality of pulse radar antennas whose transmission signal is a composite signal of two types offset by one frequency, even if the frequency of one local oscillator is one type, the same frequency By changing the pulse compression modulation method for the output signal of the transmitting signal generator and passing the received signal through a pulse compression filter corresponding to each frequency modulated and expanded pulse, the pulse compression filter can prevent the mutual reception signals between the antennas from mixing. It can also be suppressed. By changing the combination of a transmission signal generator and a pulse compression modulation generator of different orders according to each pulse, it is possible to suppress the above-mentioned contamination, and further improve the distance performance.

It can maintain long-range and short-range performance at the same time.

In other words, the scale of the device can be reduced to one level while maintaining the conventional functions.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a radar device showing an embodiment of the present invention, Fig. 2 is a conceptual diagram showing the mixing of received signals due to multiple reflections of a multi-antenna radar, and Fig. 4 is a conventional radar device with multiple antennas. FIG. In the figure, (1) is the antenna, (1a) is the first antenna, (1b) is the second antenna, (1c) is the third antenna, (2) is the circulator, (2a)
is the first circulator, (2b) is the second circulator, (2c) is the third circulator, (3
) is frequency conversion! , (3a) t-j sixth frequency converter, (3b) eighth frequency converter. (3c) is a tenth frequency converter, and (4) is an IF amplifier. (4a) is 'If, 1 IF amplifier, (4b) U second! F amplifier, (4c) is the third IF amplifier, (
5) is a distributor, (5a) is a first distributor, (sb
) is W, the 2nd distributor, (5c) is the 3rd distributor, (6)
is a pulse compression filter, (6a) is a first pulse compression filter, (6b) is a second pulse compression filter,
(6c) is the third pulse compression filter. (Sd)ij fourth pulse compression filter, (6e)
is the fifth pulse compression filter, (6f) is the Ui6 pulse compression filter, (7) is the detector, (7a) is the first detector, (7b) is the second detector, (7c) is the third detector.
(7d) is the fourth detector, (7e) is the fifth detector, (7f) is the sixth detector, (8) is the signal processor, (8a) is the first signal Processor, (ab
) is the second signal processor, (8c) is the third signal processor, (9) is the local oscillator, and (10a) is the power amplifier.
) is the first power amplifier, and (10b) is the second power amplifier. (Inc) is the third power amplifier, and αB is the frequency converter. (11a) is the fifth frequency converter, (11b) is the seventh frequency converter, (11c) is the ninth frequency converter,
ag is a synthesizer, (12a) is a first synthesizer,
(12b) is the second synthesizer, (12c) is the third synthesizer, αj is the frequency converter, (13a) is the first frequency converter, (t3b) is the second frequency converter,
(13c) is a third frequency converter. (13d) is the fourth frequency converter, (13e) is the fifth frequency converter, (13f) is the sixth frequency converter,
141 is a transmission signal generator, and (14a) is a first transmission signal generator. (14b) is the second transmission signal generator, (14c) is the third
aS is a pulse compression modulation generator. (15a) is the first pulse compression modulation generator; (15b)
is the second pulse compression modulation generator, (15c) is the third
The pulse compression modulation generator (IS is a display device). Note that the same or corresponding parts in each figure are denoted by the same reference numerals.

Claims (1)

[Claims] a first pulse compression modulation generator that generates a first pulse compression modulation signal; a first transmission signal generator; an output of the first transmission signal generator; a first frequency converter that frequency converts the output and generates a first frequency modulated expanded pulse signal; a second pulse compression modulation generator that generates a second pulse compression modulation signal;
a third transmitting signal generator, and a third transmitting signal generator that frequency converts the output of the third transmitting signal generator and the output of the second pulse compression modulation generator to generate a second frequency modulated expanded pulse signal whose frequency is offset. a first synthesizer that synthesizes the output signal of the first frequency converter and the output signal of the second frequency converter, and a local signal generator that generates a radar local signal; a fifth frequency converter that receives the output of the local signal generator and the signal of the first combiner and converts it into a transmission signal frequency; and a first power source that amplifies the output of the fifth frequency converter. an amplifier, a first circulator that switches between a transmitted signal and a received signal, a first antenna that emits a transmitted signal and receives a received signal, and a first antenna that receives a signal from the local signal generator and converts the frequency of the received signal. a first IF amplifier that amplifies the output of this sixth frequency converter, a first divider that divides the output of this first IF amplifier into two, and this first distribution a first pulse compression filter that pulse-compresses the first frequency modulated expanded pulse signal in response to the output of the first pulse compression filter; and a first detection device that detects the output of the first pulse compression filter and generates a first video signal. a second pulse compression filter that receives the output of the first divider and pulse-compresses the second frequency modulated expanded pulse signal; a second detector for generating a video signal; a first signal processor for receiving the first and second video signals and performing signal processing;
a third frequency converter that frequency converts the output of the pulse compression modulator and the output of the second transmission signal generator to generate a third frequency modulated expanded pulse signal; and the output of the second pulse compression modulator. and a fourth frequency converter that frequency-converts the output of the first transmission signal generator to generate a fourth frequency-modulated expanded pulse signal whose frequency is offset, and the third frequency converter and the fourth frequency a second combiner that combines the output signals of the converters; and a seventh combiner that receives the output of the local signal generator and the output signal of the second combiner and converts it into a transmission signal frequency.
a frequency converter, a second power amplifier for power amplifying the output of the seventh frequency converter, a second circulator for switching between a transmitting signal and a receiving signal, and radiating a transmitting signal,
a second antenna that receives the received signal; and an (8) antenna that receives the signal from the local signal generator and converts the frequency of the received signal.
), a second IF amplifier that amplifies the output of this eighth frequency converter, a second divider that divides the output of this second IF amplifier into two, and this second distribution a third pulse compression filter that pulse-compresses the third frequency modulated expanded pulse signal in response to the output of the third pulse compression filter; and a third detection device that detects the output of the third pulse compression filter and generates a third video signal. and a fourth pulse compressor for compressing the fourth frequency modulated expanded pulse signal in response to the output of the second distributor.
a fourth detector that detects the output of the fourth pulse compression filter and generates a fourth video signal; and a second detector that receives the third and fourth video signals and performs signal processing. a fifth frequency converter that further converts the output of the first pulse compression modulator and the output of the third transmission signal generator to generate a fifth frequency modulated expanded pulse signal; and a sixth frequency converter that frequency converts the output of the second pulse compression modulator and the output of the second transmission signal generator to generate a sixth frequency modulated expanded pulse signal whose frequency is offset. a third frequency converter for combining the output signals of the fifth frequency converter and the sixth frequency converter;
a ninth frequency converter that receives the output of the local signal generator and the output signal of the third combiner and converts it into a transmission signal frequency, and a power amplifier for the output of the ninth frequency converter. a third power amplifier that switches between a transmitted signal and a received signal; a third antenna that emits the transmitted signal and receives the received signal; and a third power amplifier that receives the signal from the local signal generator and outputs the received signal. a third IF amplifier that amplifies the output of the tenth frequency converter; a third divider that divides the output of the third IF amplifier into two; A fifth pulse compression filter receives the output of the second divider and pulse-compresses the fifth frequency modulated expanded pulse signal, and detects the output of the fifth pulse compression filter and generates a fifth video signal. a fifth detector that receives the output of the third distributor, and a sixth detector that receives the output of the third distributor.
a sixth pulse compression filter that pulse-compresses the frequency modulated expanded pulse signal; a sixth detector that detects the output of the sixth pulse compression filter and generates a sixth video signal;
It has a third signal processor that receives the fifth and sixth video signals and performs signal processing, the output of the first signal processor, the output of the second signal processor, and the output of the third signal processor. A radar device comprising a display device that displays.