一种基于差拍等效采样的高速信号采集前端的分析与设计

摘要

分析差拍等效采样的基本理论,设计并仿真验证一套实用的差拍采样系统.详细介绍如何根据输入信号的频率、幅度以及采集系统中对精度的要求,通过Simulink和Multisim的辅助,设计出合适的差拍采样系统.特别针对采样保持电路输出端的平滑滤波器的指标要求做了必要的分析.给出基于差拍等效采样的高速信号采集前端系统的详细设计方法与实现流程,并对整套采集前端进行了仿真分析.仿真结果表明,设计的采集前端符合高速信号采集的要求,可以应用于便携式数字示波器中.%In this paper, we analyze the basic theory of beat equivalent sampling, and design and achieve a practical beat sampling system. Firstly, it is introduced that how to design an applicable beat sampling system according to the frequency and amplitude of input signal and the requirement of system indicator precision by Simulink and Multisim. The necessary analysis on the indicator requirement of smoothing filter in the output of sample-hold circuit is carried out and the design method and implementation process of high speed signal acquisition front-end based on beat sampling are described in detail. Finally, the simulation analysis is done for the complete set of acquisition front-end. The simulation results show that the design can meet the requirements of high-speed signal acquisition. The system can be used in the portable digital oscilloscope.