基于幅度调制的连续微波雷达测距研究

为实现实时快速的全天候、高精度、大范围测距,该文提出了基于幅度调制的微波雷达测距方法.在分析主要微波雷达特点的基础上,深入探讨了该方法测尺频率和测距范围、精度之间的数学关系,并利用调制在高频载波的低频信号满足大范围测距需求,采用基于测时技术的高精度测相方法实现高精度与高速度测距,并基于混频器、测时芯片TDC-GP2等器件搭建了雷达实验系统.实验表明,基于TDC-GP2测相单元的测相精度达(2.71×10-4)°,并在2.4 GHz载波、150 kHz调制信号的条件下,对3.0～4.1 m内目标的测距实验证明了系统具有1000 m大范围测距的可行性,且目标处于3.0 m时测距精度为0.0187 m,系统单次平均测距时间为0.02～0.03 s.

Investigation on Ranging of the Continuous Microwave Radar Based on Amplitude Modulation

In order to meet the needs of high speed and real-time, all-weather, high-precision and large-scale ranging, the method of continuous microwave radar with amplitude modulation is proposed. Based on the analysis of the characteristics of the main microwave radar ranging methods, the mathematical relationships among the modulation frequency, measurement range and its accuracy are deeply discussed in the method, in which the low single frequency signal modulated on high frequency carrier signal is adopted to get large-scale ranging and also the time-measurement technology with high precision is used to achieve high precision and high speed ranging. Finally, the experimental radar system is set up by the mixer and the time-measurement chip TDC-GP2 etc. The experiments of the phase difference measurement unit based on TDC-GP2 show its accuracy is 2.71×10^-4  degrees. When the frequency of carrier signal is 2.4 GHz and that of modulation signal is 150 kHz, the experimental results under the distance from 3.0～4.1 m verify the effectiveness that the radar system could achieve large-scale ranging of 1000 m, and show that the ranging accuracy is 0.0187 m of distance of 3.0 m. Moreover, the average ranging time for single measuring point is about 0.02～0.03 s.