无线光传输系统接收机的设计及特性分析

设计和搭建了一个无线光传输系统。针对系统接收机的稳定性和信噪比要求，详细推导和分析了接收机的光电二极管特性、电路的稳定性和带宽、接收机的噪声和信噪比。详细分析了接收机中噪声的来源，给出了其影响因素及其计算方法，并参考实验器件参数实现了定量计算。在LTspice-IV上对光电二极管前置放大电路进行了建模和仿真，分析了其信号增益和噪声特性，其结果与理论分析接近。对系统进行了1 MHz方波传输实验测试，在接收端能得到较好的方波信号, 能为后续的信号处理模块提供稳定可靠的前级信号。

Design and Characteristics Analysis of Receiver for Wireless Optical Transmission System

A wireless optical transmission system is designed and built. According to the system receiver stability and signal-to-noise (SNR) requirements, the photodiode characteristics, circuit stability and bandwidth, receiver noise and signal-to-noise ratio of the receiver are deduced and analyzed in detail. The noise source in the receiver is analyzed in detail and the influencing factors and calculation methods are given. The quantitative calculation is performed according to the parameters of the experimental components. The photodiode preamplifier circuit is modeled and simulated on LTspice-IV. Its signal gain and noise characteristics are analyzed. The results are close to those of theoretical analysis. A 1 MHz square wave transmission experiment is made on the system. Good square wave signals can be obtained at the receiving end. This result shows that it can provide stable and reliable pre-stage signals for the subsequent signal processing module.