JPH0511079U - Radar receiver - Google Patents

Abstract

(57) [Abstract] [Purpose] Since the low-noise amplifier becomes oversaturated due to the occurrence of the transmission pulse signal output from the transmitter leaking into the receiver, the output pulse signal of the low-noise amplifier increases backward. The shortest target detection distance or target tracking distance becomes longer. Obtain a receiver that prevents this phenomenon. [Configuration] Leakage of a transmission pulse signal from a transmitter into a high frequency signal input terminal is input to a low noise amplifier 3 via a high frequency attenuator 2. At this time, the low noise amplifier driver 8
Means that the bias voltage of the low noise amplifier 3 is turned off while the transmitter is transmitting the transmission pulse signal, and the bias voltage of the low noise amplifier 3 is changed while the transmitter is not transmitting the transmission pulse signal. Turn it on.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a technique for shortening the minimum target detection distance or target tracking distance in a radar receiver.

[0002]

[Prior Art]

 FIG. 3 is an example of a conventional radar receiver. In FIG. 3, 1 is a receiver, 2 is a high frequency attenuator, 3 is a low noise amplifier, 4 is a detector, 5 is an attenuator drive circuit, 6 is a high frequency signal input terminal, and 7 is a video signal output terminal. .

Next, the operation of the conventional radar receiver will be described. The radar receiver receives the pulse reception signal input from the radar transmitter via the transmission / reception switching circulator and the antenna. In FIG. 3, the high frequency pulse reception signal is attenuated by the high frequency attenuator 2 by a predetermined level. At this time, the amount of attenuation is determined by the output voltage of the attenuator drive circuit 6. The output signal of the high frequency attenuator 2 is input to the low noise amplifier 3 and amplified. The high frequency pulse reception signal amplified by the low noise amplifier 3 is amplitude-detected by the wave detector 4 and is input as a video signal to the signal processor through the video signal output terminal 7. In the radar receiver, the time required from the output of the transmitted pulse to the input of the received pulse can be accurately transmitted to the signal processor by the video signal, so the target distance can be measured.

[0004]

[Problems to be solved by the device]

 When the transmitter outputs the transmission pulse signal, part of the power of the transmission pulse signal leaks to the receiver side in the transmission / reception switching circulator described above. Since this leak level is larger than the target received signal that is normally input to the receiver, in conventional radar receivers, the leak pulse signal causes the low noise amplifier to become oversaturated and the leak pulse signal increases backward. Therefore, there is a problem that the shortest target detection distance or target tracking distance becomes long.

[0005]

[Means for Solving the Problems]

 The radar receiver according to the present invention is provided with a circuit for preventing the saturation of the low noise amplifier while the transmission pulse signal is leaking to the receiver side.

[0006]

[Action]

 This invention is to reduce the low noise by turning off the bias voltage of the low noise amplifier by the above low noise amplifier driver while the transmission pulse signal is leaking to the receiver side. Prevent amplifier saturation.

[0007]

【Example】

 FIG. 1 is a block diagram showing an embodiment of the radar receiver of the present invention. In FIG. 1, 1 to 7 are the same as those of the conventional example shown in FIG. 3, and 8 is a low noise amplifier driver.

Next, an embodiment of the radar receiver of the present invention will be described. FIG. 2 is a diagram for explaining the operation of this embodiment, showing the generation timing of the transmission pulse signal and how the pulse width increases due to oversaturation of the low noise amplifier 3. In FIG. 1, the low noise amplifier driver 8 is provided to turn on and off the bias voltage of the low noise amplifier 3, and the low noise amplifier 3 is pulsed at a predetermined timing. When this timing is the timing of the transmission leakage blank gate shown in FIG. 3, the low noise amplifier 3 described above is used at the portion A, that is, when the transmission pulse signal is generated (when the leakage pulse is input to the receiver side). The bias voltage of is cut off and the supersaturated state is lost. On the other hand, at the portion C, that is, at the time of reception, the bias voltage of the low-noise amplifier 3 is applied, and the received signal is amplified as usual. As a result, the increase of the pulse width of the transmitted wave leaked by the low noise amplifier 3 (the portion B in FIG. 2) is lost, and the reception signal of the proximity target is received.

[0009]

[Effect of the device]

 As described above, according to the present invention, even if the transmission signal leaks to the receiver side, by providing a circuit that does not put the low noise amplifier in the oversaturated state, the shortest target detection distance or target tracking distance can be obtained. This has the effect of reducing the distance and improving the ability to detect and track close targets.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of this invention.

FIG. 3 is a diagram showing a conventional radar receiver.

[Explanation of symbols]

 1 receiver 2 high frequency attenuator 3 low noise amplifier 4 detector 5 attenuator drive circuit 6 high frequency signal input terminal 7 video signal output terminal 8 low noise amplifier driver

Claims (1)

Claims for utility model registration: 1. A high frequency signal attenuator connected to an input terminal of a high frequency received signal, a low noise amplifier connected to an output terminal of the high frequency signal attenuator, and the low noise amplifier. A radar receiver comprising a detector for generating a video signal connected to the output end of the attenuator and an attenuator drive circuit for generating an applied voltage for setting the attenuation amount of the high frequency signal attenuator to a predetermined value. , "OFF" by synchronizing the bias voltage of the low-noise amplifier with the timing of transmission / non-transmission of the transmission pulse signal.
A radar receiver characterized by being provided with a low noise amplifier driver for turning on and off.