FFT在现代雷达中的应用

Apllications of FFT in modern radar

快速傅里叶变换(FFT)是离散傅里叶变换(DFT)的快速算法。本文给出了离散傅里叶变换的定义及FFT算法,介绍了FFT在现代雷达中的应用。分析了FFT用作PD雷达信号处理电路中的多普勒滤波器组的原理,给出了FFT多普勒滤波器组的幅频特性。给出了FFT用于匹配滤波器的方案,用FFT计算了线性调频信号的模糊函数,并绘出了模糊函数的三维图形。计算机仿真表明,FFT计算结果与用公式直接计算得出的结果相同,而且计算量大大减小。

Fast Fourier Transform （FFT） is a kind of fast computation method of Discrete Fourier Transform （DFT）. The definition of DFT and the FFT arithmetic are given, and the applications of FFT in modem radar are introduced. The principle of which FFT is used as the Doppler filter group in PD radar signal process circuit is analyzed, and the frequency-amplitude curve of FFT is given. The design of matched filter with FFT is presented, and the ambiguity function of LFM signal is computed by FFT. Based on this, the three-dimensional figure for ambiguity function is drawn. The simulation shows that computing by FFT can get the same result as computing by formula, and the the times of computing is reduced largely.