红外探测器背景抑制读出结构设计研究

长波红外焦平面探测器一般工作在高背景下，信号电流小于背景电流，器件本身暗电流也较大，信号读出时积分电容极易饱和，这都不利于获得理想的信噪比。通过在读出电路输入级中增加电流抑制结构，可有效提高积分时间，改善动态范围和对比度。本文介绍了红外焦平面读出电路中几种典型的背景电流及暗电流抑制技术，依次叙述不同结构背景及暗电流抑制的实现原理，并比较各个结构的优缺点，针对不同电路结构的特点，通过典型电路仿真分析，确定了它们在各种红外焦平面读出电路输入级中的应用范围。

Background Suppression of Readout Circuits for IR Detectors

Long wavelength infrared focal plane arrays, which have large dark currents, usually work under high backgrounds. The photo current is much smaller than background current. Therefore the integration capacitor is easily saturated. All of these lead to a poor SNR (signal noise ratio). Longer integration time, better contrast and dynamic range can be achieved effectively by adding a current suppression structure. In this paper, several typical background suppression techniques and how they work were introduced. According to the advantages and disadvantages of each structure compared through simulation, different fields of application for which these background suppression methods were suitable had been pointed out in the use of infrared focal arrays readout circuits.