碲镉汞红外探测器前置放大电路低温稳定性研究

Low-Temperature Stability of Preamplifier Circuits for HgCdTe Infrared Detectors

摘要:

在航天工程应用过程中,发现室温下HgCdTe红外探测器前置放大电路输出正常,但是当温度降低至-55℃时,输出有振荡现象,对探测器施加红外辐照后振荡现象加剧。文章首次对该现象进行系统研究,提出了HgCdTe红外探测器电路在低温下光照后的等效电路模型,从相位裕度与增益裕度角度分析前置放大电路在低温下产生振荡的机理,并在此基础上,提出了抑制低温光照后前置放大电路振荡的解决方法,实验结果验证了该方法的有效性。

Abstract:

In aerospace applications, a HgCdTe infrared detector preamplifier circuit yields the normal output at room temperature; however, it exhibits oscillations when the temperature is reduced to -55℃, and these oscillations intensify when infrared light is irradiated to the detector. In this study, this phenomenon is systematically investigated for the first time, and an equivalent circuit model of a HgCdTe infrared detector circuit after low-temperature irradiation is presented. The mechanism of the oscillation of the preamplifier circuit at low temperature is analyzed in terms of phase and gain margins. Based on the analysis, a solution is proposed to inhibit the oscillation of the preamplifier circuit after illumination at low temperatures. The validity of the method is confirmed experimentally.