Four-quadrant laser detection automatic gain control circuit

Abstract

The invention discloses a four-quadrant laser detection automatic gain control circuit. An output end of the four-quadrant laser detector is connected to input ends of four gain amplification circuits; output ends of the four gain amplification circuits are connected to an input end of the four-channel high-speed A/D conversion circuit; an output end of the four-channel high-speed A/D conversion circuit is connected to a DDR_LVDS receiving end of an FPGA circuit; an SPI output interface of the FPGA circuit is connected to an SPI input interface of the four-channel high-precision D/A conversioncircuit; an output end of the four-channel high-precision D/A conversion circuit is connected to an input end of a four-channel voltage follower circuit; a first channel output end, a second channeloutput end, a third channel output end and a fourth channel output end of the four-channel voltage follower circuit are correspondingly connected to gain control ends, first gain reference ends, and second gain reference ends of the four gain amplifier circuits and an input end of a bias module, an input end of the bias module is connected to a bias input end of the four-quadrant laser detector, and the optimal processing of four-quadrant laser detection signals is achieved.

Description

technical field [0001] The invention belongs to the technical field of laser guidance, and in particular relates to a four-quadrant laser detection automatic gain control circuit. Background technique [0002] The automatic gain control circuit technology of laser echo signal is the core technology in the field of guidance. This technology is to perform adaptive gain control on the laser echo pulse signal after photoelectric conversion, so as to ensure that the amplified signal has a suitable amplitude for subsequent modulus Sampling processing is carried out in the conversion circuit. In actual flight, when the laser-guided weapon flies from far to near to the target, the laser energy also changes from weak to strong. Can the laser seeker output the deviation angle of projectile sight line of sight stably and accurately? The signal, so as to guide the laser-guided weapon to hit the target, depends largely on the stability and distortion of the signal after gain control. ...

AI Technical Summary

Problems solved by technology

[0004] First of all, the attenuation or amplification of each pre-amplifier, main amplifier, and bias control is gear-type control, and the dynamic range of about 60dB is divided into 3 gears, which is a severe test for the subsequent signal processing circuit. In the face of complex and changeable The use environment is easy to cause saturation distortion or loss of signal, and cannot work normally

Secondly, when the detector is very close to the target, because the energy of the laser echo is too large, even if the pre-amplifier and the main amplifier are selected to be through, the rear-end analog-to-digital converter will be saturated and distorted, and the deviation angle of the target cannot be detected, resulting in great Large blind spots, resulting in a drop in hit rate

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