集成光学高压脉冲电场传感系统中的噪声分析

Noise Analysis of Integrated Optical High-voltage Pulse E-field Sensing System

摘要:

给出了集成光学高压脉冲电场传感系统的工作原理, 使用1.2μs/50μs高压脉冲信号作为信号源对传感系统进行测试。分析了探测到的信号中噪声的主要来源: 包括传感器电极、天线及封装外壳等寄生元件产生的寄生振荡, 以及含光源、光电探测器引入的电路噪声等。采用快速傅里叶变换(FFT)对信号源和探测到的信号进行频谱分析, 得到信号源主要集中在0~160kHz范围内, 噪声频率主要集中在大于160kHz范围内。使用基于FPGA的频域数字滤波法对探测到的信号进行去噪声处理, 结果表明信号源与被探测信号的均方误差由在滤除噪声前的20.4277降为滤除噪声后的1.8678。

Abstract:

The working principles of integrated optical high-voltage pulse electric field (E-field) sensing system were analyzed and the 1.2μs/50μs high-voltage pulse signal was used as the signal source to test the sensing system. The noise sources in the detected signal mainly contain parasitic oscillation from electrodes, antennas and encapsulation of the sensor and other parasitic components, the light source noise and the circuit noise introduced by photoelectric detector, etc. The spectrums of signal source and detected signal were analyzed by using the fast Fourier transform (FFT) and the result is that the signal source is mainly concentrated in the range of 0~160kHz and the noise frequency is mainly concentrated in the range of more than 160kHz. The digital filtering method in frequency domain based on FPGA is adopted to deal with the noise in the detected signal and the result shows that the mean square error of the signal source and the detected signal drops from 20.4277 to 1.8678 after noise filtering.