HgCdTe柔性中波红外探测器放大电路设计及噪声分析

Amplification Circuit Design and Noise Analysis for An HgCdTe Flexible Medium Wave Infrared Detector

设计了一种应用于HgCdTe柔性中波红外探测器的微弱信号放大电路,该电路由电桥电路、调零电路及滤波电路组成。采用平衡电桥与仪表运算放大器INA333相结合的方式搭建电桥电路;并针对探测器直流分量过大问题,设计了可调零、带增益的信号处理电路;最后通过由二阶有源滤波器组成的滤波电路将高频噪声滤除。利用运算放大器的En-In噪声模型,对放大电路进行了噪声分析,并测试了探测器在弯曲状态下的响应性能。实验结果表明,所设计的放大电路增益为86dB,噪声均方根值低于6.1mV;柔性探测器的曲率半径为3mm;当探测器光敏面上的光谱辐照功率为6.75×10^-7W时,产生的光电信号约102.V。

In this study,we design a weak signal amplifier circuit for an HgCdTe flexible medium wave infrared detector,comprising a bridge amplifier circuit,zeroing circuit,and filter circuit.The bridge amplifier circuit is implemented with a bridge circuit and an instrument operational amplifier (INA333).In allusion to the problem of excessive direct current component of the detector,we developed a signal processing circuit with zeroing ability and gain adjustment.Subsequently,high-frequency noise is eliminated by a filter circuit composed of a second-order active filter.The En-In noise model of operational amplifiers is used to analyze the noise of the amplifier circuit and verify the response performance of the detector under different bending states.The experimental results demonstrate that the gain of the amplifier circuit is 86 dB,and the noise is below 6.1 mV.The detector is stable upon bending to a curvature of 3 mm.When the spectral irradiation power on the photosensitive surface of the detector is 6.75×10^-7 W,the resulting photoelectric signal is approximately 102 V.