一种用于FMCW雷达系统的中频信号滤波器

An intermediate frequency signal filter applied in FMCW radar systems

调频连续波(FMCW)雷达是近年来在汽车主动防撞领域新兴的一种测距传感器,该雷达系统的中频信号处理中,滤波器是最关键的部分之一。基于对干扰杂波的分析,文章设计并实现了一种用于FMCW雷达系统的中频信号滤波器,该滤波器包含高通与低通模拟滤波单元及基于DSP的FIR数字滤波单元。仿真图形与实验结果表明,所设计的滤波器能有效完成对调制泄漏信号、高频杂波信号及离散杂波信号的滤除,有助于提高雷达系统测距及测速的准确性。

Frequency modulated continuous wave（FMCW） radar is a distance measuring sensor of auto- mobile anti-collision systems in recent years. In the radar system, the filter is one of the most key cir- cuits in intermediate frequency signal processing. Based on the analysis of the interferential noises, an intermediate frequency signal filter of the FMCW radar system is designed. This filter includes high- pass and low-pass filtering circuit part and DSP based finite impulse response（FIR） digital filtering u- nit. The simulation and experimental results＂ validate the effectiveness of the filter in removing the tri- angular wave modulating signals of low frequency and high frequency signals from outside the system as well as the discrete noise. The filter can be helpful in improving the accuracy of radar ranging or ra- dar velocity measuring.