JPH01193680A - Radar apparatus - Google Patents

Abstract

PURPOSE:To contract an apparatus scale while suppressing the mixing-in of a receiving signal due to multiple reflection, by changing the pulse compression and modulation system to the output signals of transmission signal generators having the same center frequency in the first and second antenna systems. CONSTITUTION:Four pulses are obtained by combining the first and second transmission signal generators 14a, 14b having center frequencies f1, f2 and the first and second pulse compression and modulation generators 15a, 15b. Respective long and short distance pulses having center frequencies f1, f2 are synthesized by the first synthesizer 12a to be emitted from an antenna 1a and respective long and short distance pulses having center frequencies f1, f2 are synthesized by the second synthesizer 12b to be emitted from an antenna 1b. For example, the transmission signal from the antenna 1b impinges against a target to become a reflected wave signal and distributed into modulation signals having center frequencies f1, f2 by the first distributor 5a when mixed in the antenna 1a and said modulation signals are respectively inputted to the first and second pulse compression filters 6a, 6b. However, said modulation signals are suppressed because of the difference between the modulation systems thereof and erroneous confirmation is avoided. By this method, an apparatus scale can be reduced while long and short distance capacities are kept.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a radar device having a plurality of pulse radar antennas that offset nine frequencies and transmit two types of composite signals, one for friend distance and one for short distance, as transmission signals. It is something.

[Conventional technology]

In Fig. 2, (la) is the first antenna, (
lb) is the first antenna, ■ is the target, and c2υ is the building.

As shown in FIG. 2, in a radar device having a plurality of antennas, the transmitted wave from the antenna (1,) is reflected by the target object (2) and returns to the antenna (la).

It is reflected by the building (2) etc. and mixed into the antenna (lb),
It may be detected as a signal. In order to avoid such misrecognition, a plurality of local oscillators with nine different frequencies are provided to provide different transmission signal frequencies. A block diagram of a conventional radar device is shown in FIG. In the figure, (1
) is the antenna, +211-! Circulator, (3)
is a frequency converter, (4) is an IF amplifier, (5) is a distributor, (61 is a pulse compression filter, and (7) is a detector.

(8) is a signal processor, (9) is a local oscillator, (IG is a power amplifier, al) is a frequency converter, Q21 is a combiner,
α3 is a frequency converter, (141 is a transmission signal generator, α
S is a pulse compression modulation generator, Q61t! Display device, (
171 is the first antenna system.

ttst-x is the second antenna system.

In the first antenna system, a first pulse compression modulation generator (lSa), a first transmission signal generator (14a) and a first
The first frequency modulation expansion pulse signal generated by the frequency converter (13a), the second pulse compression modulation generator (15b) whose frequency is offset, the second transmission signal generator (14b), and the second The second frequency modulated expanded pulse signal generated by the second frequency converter (13b) is sent to the first synthesizer (13b).
x2a), received the signal from the fgl local oscillator (9a), frequency converted by the fifth frequency converter (lxa), power amplified by the first power amplifier (log), and the first It is radiated into the air through the circulator (2a) and the first antenna (la). 1 hit on target
The reflected wave signal passes through the first antenna (ta) and the first circulator (2a) as a received signal,
In the sixth frequency conversion & (3a), the first local
- The signal from the oscillator (9a) causes the frequency converter I to
F times signal. This IF multiplied signal first IF amplifier (4a
) and divided into two by the first divider (5a), and the first frequency modulated expanded pulse signal is amplified by the first pulse compression filter (6a). passes through the first detector (7
Similarly, the second frequency modulated expanded pulse signal passes through the second pulse compression filter (6b) and is detected by the second detector (7b) and becomes a video signal. Then, the first signal processor (8a)
sent to. The same applies to the second antenna system, but if the target reflected wave of the transmitted signal from the first antenna (la) mixes into the second antenna (lb) due to multiple reflections,
The second circulator (2b) enters the eighth frequency converter (3b) in k ways. This eighth frequency converter (3b
) has a bandpass filter corresponding to the frequency of the second local generator (9b).

The mixed signals mentioned above were now erased.

[Problem to be solved by the invention]

Such a conventional radar device 1 having a plurality of antennas has independent local oscillators with nine different frequencies, and has a device scale 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]

Both the first antenna system and the second antenna system have different pulse widths for long-distance use and short-distance use. and f2) 1-using. Here, the nine local oscillators are common, and the pulse compression modulation method for the output signal of the transmitting signal generator having the same center frequency (for example, center frequency fr) is changed in the first antenna system and the second antenna system. .

[For production]

With the above basic configuration, the signal of the second antenna system (the third
Even if the mixed signals (C and 2) are mixed into the first antenna system, the mixed signals are suppressed by the pulse compression filter because the pulse compression modulation methods for each center frequency are different in the receiving system. Furthermore, since the two local oscillators are common, the scale of the device can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram, (1) to (8) and aα to Q3.
1. (14a), (x4b), (15a), (
t5b), (161tl This is exactly the same as the above conventional device, and (9) is a local oscillator.

Figure 3 is an example of a pulse compression modulation expansion pulse, (
1) A first transmitting signal generator (with tj center frequency fl)
a first pulse compression modulation generator (] on the signal from i4a)
5a) A first frequency modulated expansion pulse which is a frequency conversion of the modulated signal from (chirp with increasing frequency).

(b) is the second transmission signal generator (with center frequency f).
14b), a second pulse compression modulation generator (
lsb) A second frequency fFi1 stretched pulse which is a frequency conversion of the modulation signal from (chirp with decreasing frequency).

In (c), the first pulse compression modulation generator (XS
a) a third frequency modulated stretched pulse, which is a frequency conversion of the modulated signal from (increasing frequency chirp);
A fourth frequency modulation expansion pulse obtained by converting the modulation signal from the second pulse compression modulation generator (15b) (chirp with decreasing frequency) into the signal from the transmission signal generator (14a) (center frequency f1). It is.

The first frequency modulated stretch pulse and the second frequency modulated stretch pulse whose frequencies are offset.

The signal received from the local oscillator (9) synthesized by the first synthesizer (12a) is frequency converted by the fifth frequency converter (lta), and power amplified by the first power amplifier (lOa). circulator (2a) and the first antenna (l
a) radiated into the air through t-. The signal that hits the target and becomes a reflected wave is sent to the first antenna (l) as a received signal.
a) and the first circulator<2a) k ways, 6th
The frequency of the signal from the local oscillator (9) is converted by the frequency converter (3a) to become an IF flaw signal. This IF flaw signal is amplified by the first IF amplifier (4a), divided into two by the first distributor (5a), and the first frequency modulation expansion pulse is.

The signal passes through the first pulse compression filter (6a), is detected by the first detector (7a), becomes a video signal, and is similarly transmitted to the second pulse compression filter (6a).
The frequency modulated expanded pulse passes through the second pulse compression filter (6b), is detected by the second detector (7b), becomes a video signal, and is sent to the first signal processor (8a). Similarly, the third frequency modulation expansion pulse and the fourth frequency modulation expansion pulse whose frequency is offset are also turned into video signals and sent to the second signal processor (8b). The output of the first signal processor (8a) and the output of the second signal processor (8a)
The output of b) is displayed on the display device u61.

The transmission signal of the second antenna system is transmitted to the first antenna system (la
), it passes through the first circulator (2a) and is turned off by the second local oscillator (9) at the sixth frequency converter (3a).
) is frequency-converted and becomes an IF multiplied signal. This IF multiplied signal is amplified by the first IF amplifier (4a).

It is distributed by the first distributor (2a). Here, the modulation signal with the center frequency f1 is input to the first pulse compression filter (6a), and the modulation signal with the center frequency f2 is input to the second pulse compression filter (6b), but the modulation methods are different. Therefore, they are both oppressed.

In this way, misrecognition can be avoided.

〔Effect of the invention〕

As shown in 9 above, in a radar device having a plurality of pulse radar antennas whose transmission signal is a composite signal of two stocks with 9 frequencies offset, even if the frequency of 9 local oscillators 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 be suppressed. ``Furthermore, by changing the combination of transmitting signal generators and pulse compression modulation generators according to the number of each pulse, it is possible to suppress the above-mentioned contamination, and further improve distance performance.

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

That is, the scale of the device can be reduced 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. 3 shows the first antenna system and the second antenna system. 2 is a schematic waveform diagram showing different combinations of transmission signal generator frequency and pulse compression modulation method in the antenna system of FIG. FIG. 4 shows a conventional radar device having multiple antennas. In the figure, (υ is the antenna, (ta) is the first antenna, (]b) tl is the second antenna, (2) is the circulator. (2a) is the first circulator, (2b) is the second circulator, +31tlj frequency converter, (
3a) is the sixth frequency converter, (3b) $1 eighth frequency converter, (4) is the IF amplifier e (4a) is the first
IF amplifier, (4b) is the second IF amplifier, 15
1t! Distributor, (5a) t! The first distributor, (
sb) is the divider of Fragment 2, (6) is the pulse compression filter,
(6a) is the first pulse compression filter, (sb
) is the second pulse pressure 1m filter, (6c)t! Third pulse compression filter, (6d) tl! 4th pulse compression filter, (7) is a detector, (7a) is a first detector, ('rb) is a second detector. (7c) is the third detector, (7d) is the fourth detector, (8) is the signal processor, (8Jl) is the first signal processor, (sb) is the second signal processor, (9) is the local oscillator, αI is the power amplifier, (tOa) is the first power amplifier, (tab) is the second power amplifier, tinFs
a frequency converter, (lla) is a fifth frequency converter;
(lxb) is the seventh frequency converter, and α3 is the synthesizer. (lza) is the first synthesizer, (12b) is the second synthesizer, 03d frequency converter, (13a) is the first frequency converter, (13b) is the second frequency converter, (13c)
) is the third frequency converter, (13d) is the fourth frequency converter, α4 is the transmission signal generator, (14a) is the first transmission signal generator, (14b) is the second transmission signal generator ,
n5rx pulse compression modulation generator. (lSa) is the first pulse compression modulation generator, (lsb
) is the second pulse compression modulation generator, and αe is the display device. It was a cabinet. 0) is the first frequency modulated expansion pulse, (b) is the second frequency modulation expansion pulse, (c) is the third frequency modulation expansion pulse, and (b) is the fourth frequency modulation expansion pulse. Note that the same or corresponding parts in the two figures are designated 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 transmission signal generator, and a second frequency modulation expanded pulse signal whose frequency is offset by frequency converting the output of the second transmission signal generator and the output of the second pulse compression modulation generator. 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 the transmitted signal and receives the received signal, and a first antenna that receives the 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 the transmitting signal and the receiving signal, and radiating the transmitting signal,
a second antenna that receives a received signal; an eighth frequency converter that receives the signal from the local signal generator and converts the frequency of the received signal; and a second frequency converter that amplifies the output of the eighth frequency converter. an IF amplifier, a second divider that divides the output of the second IF amplifier into two, and a third divider that receives the output of the second divider and pulse-compresses the third frequency modulated expanded pulse signal. a pulse compression filter, a third detector which detects the output of the third pulse compression filter and generates a third video signal, and a fourth detector which receives the output of the second distributor.
a fourth pulse compression filter that pulse-compresses the frequency modulated expanded pulse signal; a fourth detector that detects the output of the fourth pulse compression filter and generates a fourth video signal;
a display device having a second signal processor that receives the third and fourth video signals and performs signal processing, and displays the output of the first signal processor and the output of the second signal processor; A radar device comprising: