JPH0545584U - Monopulse radar device - Google Patents

Abstract

(57) [Summary] [Purpose] In a monopulse radar system, if the sum and difference channels are made equal in length with a single frequency, the radar system cannot be operated in a wide band. [Structure] A reference signal capable of oscillating in a wide band is input, and the phase variator of each line is controlled by the phase difference between the reference signals of the sum and difference channels to eliminate a phase error in the wide band. In addition, the difference signal AG is adjusted by the gain difference between the reference signals of the sum and difference channels.
Controls the C amplifier and eliminates gain error in a wide band. [Effect] The monopulse radar device can be used in a wide band.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is, for example, a radar device for radiating and reflecting an electromagnetic wave to a target to be detected, extracting necessary information from the received signal, and capturing and tracking the target, particularly a monopulse. The present invention relates to a radar device.

[0002]

[Prior Art]

 FIG. 2 is a block diagram of a conventional monopulse receiver. In the figure, 1 is a monopulse antenna, 2 is a mixer preamplifier for sum signals and difference signals, 3 is an AGC amplifier for sum signals and difference signals, and 5 is a sum signal. A detection circuit 6 for the sum signal and an AGC circuit for the sum signal for inputting the AGC voltage to the sum signal and the difference signal.

The conventional monopulse radar device has the above-described configuration because it is difficult to equalize the sum and difference signal lines due to mounting in the device and arrangement of each component in the sum signal and difference signal line. The signal coming from a certain antenna 1 is separated into a sum signal and a difference signal, and the sum signal passes through a sum signal mixer preamplifier 2 and then the sum signal AGC amplifier 3 output and the difference signal AGC amplifier 3 output. Are input to the phase detector 7, and the output of the phase detector 7 is used as the tracking error voltage. The sum signal AGC amplifier 3 output signal is detected by the sum signal detection circuit 5, and the output level is detected by the sum signal AGC circuit 6 and the AGC voltage is detected by the sum signal AGC amplifier 3 and the difference signal AGC amplifier 3. It was output to and the gains of the sum and difference signals were matched.

[0004]

[Problems to be solved by the device]

 In the conventional monopulse receiver, the sum signal AGC circuit is controlled so that the output is constant with respect to the input of the sum signal AGC amplifier. The AGC amplifier for difference signals is also controlled by the output of the AGC circuit for sum signals, but the AGC amplifier for difference signals has variations in frequency characteristics and phase characteristics as compared to the AGC amplifier for sum signals, and gain. However, there is a problem that the accuracy of acquisition and tracking with respect to the target deteriorates because the error is not constant and there is an error.

The present invention has been made to solve the above problems, and when a radar device is used over a wide band, a control circuit is added to minimize an error with respect to a target signal. This is a radar device with improved accuracy.

[0006]

[Means for Solving the Problems]

 The monopulse radar device according to the present invention comprises a phase variable circuit for compensating for variations in frequency characteristics and phase characteristics between receiver channels and a phase control circuit for controlling the phase variable circuit. The feedback loop for the error and the AGC error configured by the AGC circuit for comparing and correcting the output of each channel by using the detection circuit to correct the variation of the frequency characteristic between each channel in AGC. It is the addition of two circuits of the feedback loop for.

[0007]

[Action]

 In this invention, by providing a reference signal to the sum and difference signal system, it is possible to improve the target acquisition / tracking accuracy by suppressing the phase between each channel and the AGC error to a minimum regardless of the frequency.

[0008]

【Example】

 Example 1. FIG. 1 is a diagram showing an embodiment of this invention. 1 to 3 and 5 to 7 are exactly the same as the above conventional device. 4 is a phase variable device, 12 is a phase control circuit, 9 is a gate oscillator, 11 is a reference oscillator, 8 is a gate circuit, 13 is an adder, 5 is a detection circuit, 7 is a phase detector, and 6 is an AGC circuit. is there.

In the monopulse radar device configured as described above, the reference signal is used to correct the phase difference between the sum channel and the difference channel and the variation in the frequency characteristic in the AGC circuit. Regarding the phase difference, the output of the sum channel as the reference signal and the output of the difference channel are compared by the phase detector 7, the output of the phase detector 7 is input to the phase control circuit 12, and the output of the phase control circuit 12 causes the phase variable device 4 By controlling, the variation of the phase characteristic due to the frequency of the sum channel and the difference channel is corrected. Further, in order to correct the variation between channels due to the frequency characteristics of the AGC circuit, the output of the sum channel and the output of the difference channel, which are reference signals, are compared by the AGC circuit 6, and the output of the AGC circuit 6 is added to the AGC amplifier 3. Will be corrected by

FIG. 3 shows the timing of the radar signal and the reference signal. The reference signal is input to the AGC amplifiers of the sum channel and the difference channel during a period when the radar signal is not used in the radar cycle, and the output of the phase detector 7 is taken out at the output timing of the gate oscillator 9 The output is compared and fed back. Further, in the AGC correction, the signal input to the AGC amplifier is taken out from the output of the detection circuit 5 at the output timing of the gate oscillator 9 and the output of the AGC circuit 6 is compared and fed back. In the figure, (a) is the output waveform of the reference oscillator 11, which is a continuous wave. (B) is the output of the gate oscillator 9, (c) is the output of the gate circuit 8, and the reference signal is output to a range not used as a radar. (D) is an input signal of the AGC amplifier 3 in the sum signal line, and the received signal and the reference signal are included therein. (E) is an input signal of the AGC amplifier 3 in the differential signal line having two systems. (F) is the output of the AGC amplifier 3 in the sum signal line, which includes the received signal and the reference signal. (G) is the output signal of the AGC amplifier 3 in the difference signal line, and includes the same received signal and reference signal. (H) is the output signal of the phase detector 7, which is the detection output of the same received signal and reference signal. (I) is the output of the phase control circuit 12, and its (c) voltage works so that the (a) output of the reference signal of the phase detector 7 is always constant. Further, (j) is the output of the detection circuit 5, which contains the received signal and the reference signal. (K) is the output of the AGC circuit 6, and its voltage (e) works so that the reference signal output (d) of the detection circuit becomes constant. By the above operation, the phase error and AGC error of the sum channel and the difference channel when the radar device is operated in a wide band can be suppressed to a minimum regardless of the frequency, and the target acquisition / tracking accuracy can be improved.

[0011]

[Effect of the device]

 As described above, the present invention uses the phase variator and the AGC circuit at the positions where the phase between the receiving signal lines and the AGC should be corrected, and the phase of the sum signal and the difference signal of the frequency band used by the feedback loop based on the reference signal. There is an effect that the error and the AGC error can be easily suppressed and the accuracy of capturing and tracking can be improved. Further, there is an effect that the radar device can be used in a wide band as necessary under the ECM environment.

[Brief description of drawings]

FIG. 1 is a diagram showing a monopulse radar device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a conventional monopulse radar device.

FIG. 3 is a diagram showing the timing of a monopulse radar device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Antenna 2 Mixer Amplifier 3 AGC Amplifier 4 Variable Device 5 Detection Circuit 6 AGC Circuit 7 Phase Detector 8 Gate Circuit 9 Gate Oscillator 10 AGC Attenuator 11 Oscillator 12 Phase Control Circuit 13 Adder

Claims (1)

[Scope of utility model registration request] 1. A mixer preamplifier for sum signals for converting a sum signal received by a monopulse antenna,
A for sum signal that limits output signal from mixer preamplifier
A GC amplifier, a difference signal mixer preamplifier that converts the two difference signals obtained by the monopulse antenna, a difference signal AGC amplifier that limits the output signal from the difference signal mixer preamplifier, and two difference signal A
Depending on the output of the phase variator that detects the phase difference between the output signals of the phase variator and the AGC amplifier for the sum signal, and the phase variator that varies the phase according to the frequency using the output of the GC amplifier. A phase control circuit for controlling the phase variator and a detector for detecting the amplitude difference between the sum signal and the difference signal,
An adder for adding the difference signal AGC in order to compare the detection outputs of the sum signal and the difference signal and correcting the gain difference due to the frequency characteristic between the channels, an oscillator capable of varying the frequency for generating the reference signal, and its output A monopulse radar device including an AGC attenuator for controlling the level and a gate oscillator / gate circuit for creating timing.