JPS63305267A - Radar system - Google Patents

Abstract

PURPOSE:To detect a target even if a jamming radiowave is present, by generating a signal for offsetting the jamming radiowave, adding the signal to the received signal from a radar antenna, and offsetting the jamming radiowave at a high frequency stage. CONSTITUTION:The amplitude and the phase of a signal, which is obtained with an omnidirectional antenna receiver 11, are controlled with a modulator 12. The signal is added to a signal, which is received with a radar antenna 1, through a directional coupler 13. A modulation control circuit 17 reads the amplitude and phase data of a pattern in the azimuth of a jamming wave in a pattern memory 18 based on an antenna azimuth signal from a system control part 9 and a jamming-wave azimuth signal from a jamming-wave azimuth signal detector 16 and controls the modulator 12 so that a signal, which has the same amplitude and the reverse phase as those of the jamming signal that is received with the radar antenna 1, is obtained. When the signal, which is controlled in this way, is added to the signal, which is received with the radar antenna 1, the side lobes or back lobes in the azimuth of the arriving jamming wave are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radar device with high ECCM (interference wave protection) properties that prevents interference signals from being received.

[Conventional technology]

FIG. 3 is a block diagram showing the configuration of a conventional general radar device. In the figure, 1 is a radar antenna such as a parabolic antenna, 2 is a transmission/reception switch, 3 is a radar transmitter, and 4
5 is a radar receiver, 5 is a signal processor, 6 is an indicator, 7 is an antenna drive unit that rotates the radar antenna 1, and 8 is an antenna rotation speed.

An antenna control unit that controls the orientation, etc.; 9, a system control unit that generates antenna orientation signals; 1o, an omni antenna; and 11, an omni antenna receiver.

FIG. 2 shows the radiation characteristics of the radar antenna 1 and the omni antenna 10.

First, the basic operation of the radar will be explained. A reception signal generated by the radar transmitter 3 is radiated from the radar antenna 1 via the transmission/reception switch 2, is reflected by a target object, and is received by the radar antenna 1 again.

This received signal is sent to the radar receiver 4 via the transmission/reception switch 2.
is amplified and frequency converted. The signal processor 5 performs various processing on the received signal to generate a video signal, which varies depending on each radar, and sends the received signal to the indicator 6. In the indicator 6, P P I (Plan Po5iti
The target object is displayed on the indicator 6, such as on Indication).

If there is a jamming signal, it is received by the side lobe or back lobe of the radar antenna 1, and the jamming signal is displayed in a straight line or dotted line on the indicator 6 in the direction of the side lobe or back lobe, indicating that the target object becomes difficult to detect. When the level of the interference radio waves is high, the entire surface of the indicator 6 becomes pure white, making it completely impossible to detect the target.

Introduction to radar systems (Introduction) as a method to remove interference signals.
traduction to Radar System
ms) (MCG RAW-HI LL Publishing, 5KO
S 1deLobe Cancellation on page 559 of ``LNIK'', et al.
How to do this is introduced.

This will be explained using FIGS. 3 and 2. The omni antenna 10 and the omni antenna receiver 11 receive signals in all directions. The relative radiation intensities (reception gains) of the radar antenna 1 and the omni antenna 10 have a relationship as shown in FIG.

The radar receiver 4 compares the received signal level from the radar antenna 1 and the reception level from the omni antenna 10 and determines that the signal received by the radar antenna 1 is at a higher level than the signal level received by the omni antenna 10. It has a function that extracts only the signal of.

Therefore, since the signal received by the side lobe, that is, the jamming radio wave, is larger than the signal received by the omni antenna 10, it is possible to avoid receiving the jamming radio wave.

[Problem that the invention seeks to solve]

Conventional radar equipment is configured as described above, so
Although the jamming radio waves can be eliminated, when the jamming radio waves arrive, the signal of the target that the main lobe is facing is also switched off in the radar receiver 4, so that the signal from the target that is originally intended to be detected is switched off in the radar receiver 4. There was a problem in that no signal was sent, and therefore the indicator 6 could no longer detect the target object.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a radar device that can detect a target object even when there is interference radio waves.

[Means for solving problems]

The radar device according to the present invention cancels the signal received by the side lobe or back lobe of the radar antenna by controlling the amplitude and phase of the signal received by the omni antenna and adding these to the signal received by the radar antenna. It was made in a similar manner. This method is described in “Introdu
Although it is introduced on the same page of ``action to Radar System'', it has not been realized because no concrete means have been considered so far.

[Effect]

In this invention, in order to generate a signal that cancels out jamming radio waves, information on the all-round pattern of the radar antenna is stored in a pattern memory, and this all-round pattern information is combined with the information on the radar antenna and the interference signal prepared separately. Read and use the wave direction information.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, the same or equivalent parts as in FIG. 3 showing the prior art described above are designated by the same reference numerals. In the figure, 12 is a modulator that controls amplitude and phase, 13 is a directional coupler, 14 is an antenna for detecting interference wave direction, 15 is an interference wave receiver, 16 is an interference wave direction signal detector, and 17 is modulator control. circuit.

18 is a pattern memory made of semiconductor memory.

Next, the operation will be explained. Here, the interference direction detection antenna 14. Interference receiver 15. The part consisting of the interference wave azimuth signal detector 16 is a so-called ESM (E 1ec
This is an electronic support measure called tric support measurement, in which the arrival direction signal of unknown radio waves (jamming radio waves) is obtained. Omni antenna receiver 11
The amplitude and phase of the obtained signal are controlled in the modulator 12, and the signal is sent to the radar antenna 1 via the directional coupler 13.
added to the signal received by

The modulator control circuit 17 reads the amplitude and phase information of the interference wave azimuth pattern from the pattern memory 18 based on the antenna azimuth signal from the system control unit 9 and the interference wave azimuth signal from the interference wave azimuth signal detector 16. The modulator 12 is controlled so that a signal having the same amplitude and opposite phase as the interfering radio wave received by the radar antenna 1 is obtained. When the signal controlled in this way is added to the signal received by the radar antenna 1, the pattern of the radar antenna 1 shown in Fig. 2 is equivalent to eliminating the side lobe or back lobe of the direction of arrival of the interfering wave. become.

Therefore, even if the interference radio waves in the direction informed by the ESM are received by the radar antenna 1, they will not enter the radar receiver 4. Therefore, the radar receiver 4 is always alive and the target is always detectable.

In the above example, the case of a radar device using a parabolic antenna was explained, but even in a phased array router, the entire circumference pattern is actually measured for all cases when the main beam is electronically scanned, and the pattern is stored in the pattern memory. By doing so, you can obtain the same effect.

〔Effect of the invention〕

As described above, according to the present invention, the entire circumference pattern information of the radar antenna is stored in the pattern memory,
This all-round pattern information is read out using radar antenna information and jamming wave azimuth information prepared separately, a signal is generated to cancel the jamming waves, and this is added to the reception by the radar antenna to cancel the jamming waves at the high frequency stage. Since the receiver is configured to be turned off, the receiver is not saturated by the jamming radio waves, and the target can be detected even in the presence of the jamming radio waves.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a radar device according to an embodiment of the present invention, FIG. 2 is an antenna characteristic diagram in the present invention and the conventional method, and FIG. 3 is a diagram showing the configuration of the radar device in the conventional method. FIG. 1 is a radar antenna, 2 is a transmission/reception switch, 3 is a radar transmitter, 4 is a radar receiver, 6 is an indicator, 9 is a system control unit, 10 is an omni antenna, 12 is a modulator, 13 is a directional coupler , 14 is an antenna for detecting interference direction, 17 is a modulator control circuit, and 18 is a pattern memory. Patent applicant: Mitsubishi Electric Corporation

Claims (1)

[Claims] a radar antenna, an omni-directional omni-antenna, a radar transmitter that provides a transmission signal to the radar antenna, a radar receiver that processes a received signal of the radar antenna, and the radar antenna and the radar receiver. a transmitting/receiving switch connected between the transmitting signal and the receiving signal to switch between the transmitting signal and the receiving signal, and a system control section generating an antenna direction signal, etc., and controlling the receiving sensitivity of interference waves to be lowered. In the radar device, a jamming wave direction detection antenna detects the direction of the jamming wave, a pattern memory that stores an omnidirectional reception pattern of the radar antenna, and a modulation that controls the amplitude and phase of the received signal from the omni antenna. a modulator control circuit that controls the modulator with a signal that reads amplitude and phase information of the pattern of the direction of the jamming wave from the pattern memory using the antenna direction signal and the jamming wave direction signal; a directional coupler connected between the switch and the radar receiver and adding the output signal of the modulator to the signal received by the radar antenna; A radar device characterized in that it is configured to cancel lobe levels.