LFMCW雷达差频信号滤波电路设计

Design of difference frequency signal filter circuit for LFMCW radar

理想情况下LFMCW雷达差频信号在规则区内是标准正弦信号,但大量实测信号表明,差频信号中含有成分复杂的噪声信号,严重影响了雷达的测距精度。采用模拟滤波器,是滤除这些噪声信号最直接的办法。针对LFMCW雷达差频信号信号频带与噪声频带相近的特点,介绍了一种计算简单的模拟椭圆滤波器设计方法,分别设计了椭圆函数低通、高通滤波器,然后通过级联的方式构成带通滤波器。实测实验表明,该方法设计的带通滤波器可以有效地降低噪声干扰,提高LFMCW雷达差频信号质量。

Under ideal conditions,the LFMCW radar difference frequency signal is a standard sinusoidal signal in the regular region,but a large number of measured signals show that the difference frequency signal contains complex noise signals,which seriously affects the ranging accuracy.The use of analog filters is the most direct way to filter out these noise signals.Aiming at the characteristics of the frequency band of LFMCW radar is similar to the noise band,a simple design method of simulated elliptic filter is introduced.The elliptic function low pass and high pass filter are designed respectively,and then the cascade method is used to form a band pass filter.Experimental results show that the proposed band-pass filter can effectively reduce the noise interference and improve the quality of LFMCW radar frequency difference signal.