【摘要】 针对主动式红外弱光检测,本文研究如何提高和稳定雪崩光电二极管APD电路增益,及其光电匹配参数。该方法根据APD增益或噪声与反向偏压分别呈指数或线性关系,采用温度补偿电路稳定APD偏压,通过调整串联稳压管获得接近APD的温度系数,使器件工作点接近其击穿电压,获得超100倍的增益。采用交流耦合的本级负反馈低电压低噪声NPN晶体管电路,提高频响和晶体管截止频率fT。在保持电路稳定性的前提下,电压增益可提高到原来的2～3倍,光电系统灵敏度提高23dB以上。功率激光二极管LD的PN结温度变化导致波长漂移,难与极窄带宽匹配。抑制背景辐射的干涉滤光片带宽介于10～15nm为宜。更多还原

【Abstract】 Aimed at active weak IR detection, how to get the stable high gain from Avalanche Photodiode (APD) circuits and its opto-electronic matching characters are researched. The methods are relation with APD exponent gain and linear noise with its reverse bias voltage. It gets closed to temperature coefficient by serial Zener diodes and always-stable bias voltage to APD near break voltage at real PN junction temperature, and is over 100 times gain with temperature complement circuits. Transistor cut-off frequency and its response are increased by NPN type transistor with an improved a.c. couple low noise and low voltage supplier negative feedback circuits. The system voltage gain enhances 2 to 3 times, and opto-electronic sensitivity rises over 23 dB. Because PN junction temperature of power LD changes causes wavelength drift, it is very difficult to match extremely narrow bandwidth interference filters. So the interference filter bandwidth between 10 and 15 nm is available for background radiation depression.更多还原