基于GPIB接口的数字式相关检测实验研究

The research of digital correlation detection experiment based on GPIB interface

利用数字式存储示波器的GPIB接口与微机相连组成数字采集系统，可以在微机上对采集的信号进行检测与处理。该文以微弱信号的相关检测为背景，阐述了通过GPIB采集数据，并在微机端进行数字相关检测，获取信号幅度和相位信息的实验。该系统简便易实现，并且完全数字化的，从而避免了传统模拟方法设计相关检测电路，电路复杂度高，器件的工作线性区间受限，易受干扰和温度漂移等缺点。通过实验，学生可以更深入理解相关检测的原理，增加采样点数可提高结果的精度。

A digital sampled-data system is designed, which uses the connection between the computer and the digital oscilloscope by GPIB. The sampled signal can be detected and processed on computer. In this article we take an example of correlation detection on weak signal to illustrate an experiment, in which we carry out the digital correlation detection on computer, using the data sampled by GPIB, to gain the amplitude and phase information of the original signal. Compared with the traditional analog method, the system which is fully digitized and can be easily realized, could avoid many shortcomings, such as complex circuit ; restriction of devices working in linear interval ; easily disturbed ; and temperature drifting. Through the experiment students could take a deeper understanding of the principle of the correlation detection, and increasing the sampling dots could improve the detection precision.