Radar antenna received signal preprocessing device and preprocessing method

Abstract

The invention relates to a radar antenna received signal preprocessing device and preprocessing method. The device is additionally provided with a directional coupler, a detector, a microwave switch,an optical switch and a control unit, and is provided with n light emitting modules, amplifiers of the light emitting modules have different magnification times, which correspond to different power intervals of microwave signals. According to the processing method, microwave signals received by an antenna are divided into two paths by the directional coupler, the majority of the microwave signalsenters the microwave switch, and a small part of the microwave signals enters the detector to detect a power value. The control unit selects the light emitting module corresponding to the magnification times of the corresponding power interval according to the current signal power value depending on the detection result, controls the microwave switch to access the current microwave signal, and controls the optical switch to connect an output end of the selected light emitting module to a transmission optical fiber; the microwave signals are amplified and converted into optical signals; and theoptical signals are sent to a light receiving module by the transmission optical fiber. The magnification times are selected according to the signal power, the large signal does not need to be attenuated, and the small signal has a large amplification rate, thereby ensuring the dynamic range of the entire radar system.

Description

technical field [0001] The invention relates to the technical field of radar receiving, in particular to a radar antenna receiving signal preprocessing device and a preprocessing method. Background technique [0002] Radar and antennas are widely used in modern communication systems. There is a certain distance between radar and antenna and the central computer room. However, in some actual situations, the distance between the radar, antenna, etc. and the central computer room is relatively long, some are several kilometers away, and some are even tens of kilometers away. In the case of a long distance, the loss of the radar signal transmission in the cable is very large, and it needs to be transmitted by optical fiber. In this way, signals received by radars, antennas, etc. are usually amplified and then converted into optical signals for transmission. Since the amplitude of the signal received by the radar, antenna, etc. fluctuates, the signal power is uncertain. The ex...

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Problems solved by technology

The advantage of the first method is that the entire system will not be saturated when receiving a large signal, and avoid nonlinearity and signal distortion caused by saturation when the entire system receives a large signal; but because the amplifier multiple of this method is based on the large signal Designed, the magnification is relatively small, so when the received signal power is low, the magnification is not enough, affecting the dynamic range of the entire system

The advantage of the second method is that the large signal is attenuated by the numerically controlled attenuator to avoid nonlinearity and signal distortion caused by saturation, but after the large signal is attenuated by the numerically controlled attenuator, the noise figure of the large signal will be increased

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