数字滤波幅度测量性能与采样频率的关系研究  

Study on the Dependence of Digital Filter Performances on Sampling Frequency for Amplitude Measurements

作　　者：邓晓[1] 邓智[1] 刘以农[1] 

机构地区：[1]粒子技术与辐射成像教育部重点实验室(清华大学),清华大学工程物理系,北京100084

出　　处：《核电子学与探测技术》2012年第9期1007-1011,共5页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金项目(10735060)资助

摘　　要：针对目前比较通用的核电子学数字信号处理电路结构,分析了数字滤波性能与模数转换器采样频率的关系。解析推导了数字滤波幅度测量性能与采样频率的定量关系,给出在一定采样频率下数字滤波所能获得的最佳信噪比和数字梯形滤波的噪声指数。还通过数值仿真和基于数字示波器采样的幅度测量系统,对幅度测量误差与采样频率的关系进行了验证。实验测得的ORTEC 142AH电荷灵敏前放的噪声随采样频率的变化规律与理论分析基本一致,较好地验证了理论分析。该研究为核电子学中数字幅度测量的采样频率选择提供了理论依据。Based on commonly applied digital signal processing circuit in nuclear electronics, the dependence of digital filtering performance on ADC sampling frequency has been analyzed. Derive analytically the amplitude measurement performance on the sampling frequency, and then obtain the optimum signal to noise ratio un der certain sampling frequency as well as noise index of digital trapezoidal filter. The dependence of amplitude measurement fluctuation on the sampling frequency is demonstrated by the numerical simulation and measure ments with digital oscilloscope sampling. The dependence of the noise of ORTEC 142AH charge sensitive pre amplifier on the sampling frequency is consistent with the theoretical results. This study offers a theoretical cri terion for sampling frequency selection in digital amplitude measurements.

关 键 词：核电子学 数字滤波 模数转换器 噪声指数 

分 类 号：TL82[核科学技术—核技术及应用]