基于等效时间采样的探地雷达回波信号采样方法研究

探地雷达是一个工作频率上限约为1GHz的时域系统。如果采用传统的实时采样技术，采样信号的频率将会很高，从频谱角度分析，对采样系统的频带要求更高。实际上，作为雷达数字显示系统前端的A/D转换器，其采样速率很难满足采样定律对实时采样的要求。为此，本文提出了一种对探地雷达回波信号这种特殊的高频信号进行采集的方法，即等效时间采佯方法，并设计实现了等效时间采样的具体电路，包括产生步进采样脉冲的高精度步进系统、采样门电路等。

Research on a Sample-Collecting Method of Echo Data of Ground Penetrating Radar Based on Equivalent Time Sampling

Ground Penetrating Radar(GPR) is a time domain system with the 1 GHz upper-limit of operating frequency. According to the Nyquist sample-collecting theory, adopting of the traditional real time sample-collecting technology will make the frequency of the sample-collecting signal be high. From analysing of the frequency spectrum, the demand of the frequency spectrum of the sample-collecting system will be rigorous. In fact, for the A/D convertor being the front of the radar digital display system, it is very difficult to satisfy the demand of real time sample-collecting. This paper presents a method of collecting the sample of GPR echo signal which is a special kind of high frequency signal, namely the equivalent time sampling method, and designs some idiographic circuits including the step system which generates the step acquisition pulse and the sample-collecting gate circuit.