基于格理论的非均匀稀疏线阵旁瓣结构的分析方法

Analysis of Side Lobe Structure of Nonuniform Sparse Linear Array Based on Lattice Theory

在有限个阵元的情况下,非均匀稀疏线阵能得到更大的阵列孔径.但由于其是对空间信号的非均匀采样,不能通过常规的傅立叶变换方法求得其峰值旁瓣解析表达式.本文提出了一种基于格理论的非均匀稀疏线阵的旁瓣结构分析方法.首先建立了阵列流形格的数学模型并对其物理含义进行了仿真分析,然后推导了阵列流形格最近格点与峰值旁瓣的对应关系,从而将非均匀稀疏线阵峰值旁瓣结构分析问题转化为求距阵列流形格原点最近格点问题.该方法可以准确地确定非均匀稀疏线阵旁瓣中增益大于门限电平的旁瓣个数及其各自的方位.计算机仿真结果表明了该方法的有效性和准确性.

For a given number of elements sparse linear array provides a larger aperture.However,it samples the incident signal nonuniformly,so the analytic expression of its peak sidelobes can′t be obtained by traditional FFT method.An analysis of side lobe structure of non-uniform sparse linear array based on lattice theory is presented.First,the array manifold lattice is modeled.Then the relationship between nearest lattice points and the peak sidelobes structure is investigated.Thus the problem of getting the sidelobe peaks becomes the problem of finding the nearest lattice points from the origin in array manifold lattice.This method can find the number and wavenumber vector with respect to peak side lobe whose gain is higher than the given gain precisely.Computer simulation results are presented to show its effectiveness and accuracy.