A Four-quadrant Detector Signal Conditioning Circuit for Displacement Feedback System

Abstract

The invention discloses a four-quadrant detector signal conditioning circuit used in a displacement feedback system, which comprises a four-quadrant detector, a current blocking module, a transimpedance amplification module and an analog operation module. The four-quadrant detector converts the laser signal into a current signal, and the current blocking module extracts the AC component containing displacement information in the current signal; the transimpedance amplification module connects the output signal of the current blocking module, converts it into a voltage signal and amplifies it After the output; the analog operation module is connected to the voltage signal output by the transimpedance amplifier module for analog operation and low-pass filtering, and the three-dimensional dynamic displacement information of the target is calculated. The invention can realize high-precision three-dimensional dynamic displacement measurement, is suitable for building a displacement feedback system, and has the advantages of high gain, high bandwidth, simple circuit structure and low noise.

Description

technical field [0001] The invention relates to the field of photoelectric detection, in particular to a four-quadrant detector signal conditioning circuit used in a displacement feedback system. Background technique [0002] The working principle of the four-quadrant detector is as follows: the four-quadrant detector is composed of four identical photodetectors arranged in four quadrants. Generally, the laser beam irradiated on the photosensitive surface of the four-quadrant detector uses a circular spot and the energy distribution is uniform. When the beam is irradiated on the surface of the four-quadrant detector, if the center of the beam is located at the center of the four-quadrant detector, the light power received by each quadrant is the same , output equal photocurrent; if the center of the beam deviates from the center of the four-quadrant detector, the received light energy will also change due to the different spot areas on the four quadrants, resulting in differ...

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Problems solved by technology

[0010] The purpose of the present invention is to provide a four-quadrant detector signal conditioning circuit for displacement feedback system, which is used to solve the problem that the existing technology is difficult to precisely extract the weak AC signal in the photocurrent, and it needs to adopt a multi-stage amplification structure, and the circuit structure is complicated. It is easy to introduce circuit noise, and it is difficult to achieve high bandwidth under high gain

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