针对恒虚警工作方式下, 噪声、信号及倍增因子之间相互作用的问题, 分析了倍增因子、背景辐射对APD探测系统性能的影响以及恒虚警补偿方式的工作原理, 建立了恒虚警下背景辐射与倍增因子的关系模型。通过求取有、无背景光时系统可探测到的最小信号功率, 建立了APD性能的评估模型, 设计实验对模型进行了验证, 利用该模型分析了不同噪声对APD探测性能的影响。结果表明, 随着背景光增强, 其对APD的性能影响逐渐增大, 且增大速率逐渐减缓; 暗电流噪声较小时, 背景光对APD作用较为明显, 随着暗电流噪声的增大, 背景光对系统影响迅速减小, 最终趋于平稳; 背景光对APD的影响随热噪声、放大电路噪声的增大而均匀增大。

Aiming at the interaction between noise, signal and multiplication factor under the working mode of constant false alarm, the effects of multiplication factor and background radiation on the performance of APD detection system and the working principle of constant false alarm compensation mode were analyzed. And the relationship model between background radiation and multiplication factor under constant false alarm is established. By evaluating the minimum signal power that can be detected with or without background light under certain conditions, an evaluation model of APD performance was established, and the model was verified by experiments. The influence of different noise on APD detection performance was analyzed. The results show that as the background light increases, the influence of background light on APD performance increases gradually, and the growth rate gradually decreases. When the dark current noise is small, the background light has a more obvious effect on APD. With the increase of dark current noise, the influence of background light decreases rapidly and eventually stabilizes. The effect of light on APD increases uniformly with the increase of thermal noise and noise of the amplifier circuit.