畸变直线阵阵增益计算及仿真研究

Calculation and simulation of the gain of distorted line array

阵增益是直线阵最重要的技术指标之一,理想直线阵以半波长布阵,阵增益为阵元数的函数。阵形畸变导致阵元间距发生改变,使直线阵增益显著下降,一方面由于各阵元接收信号的相位差发生变化,另一方面因为各阵元接收信号的相关性改变。从理想阵形情况直线阵的增益出发,并假设阵形畸变不改变各阵元接收信号的相关性,给出了畸变直线阵信号增益、噪声增益和阵增益的计算方法。仿真了直线阵畸变为圆弧形,阵增益随畸变参数的变化情况,分析给出了信号从不同方向入射、阵形未知/已知时,阵增益与信号增益、噪声增益变化的关系。

Array gain is one of the most important technical indicators for a line array. An ideal line array is with a half-wavelength between the elements, and there is a functional relationship between array gain and array element number. When the shape of an array is changed, the array gain reduces dramatically due to the fact that the phase of the signal received by each element and the correlation between these signals are changed. Based on the gain of an ideal line array, the calculation methods of signal gain, noise gain and array gain of a distorted line array are deduced on the as-sumption that the variation of the array shape doesn＆#39;t have an impact on the correlation. Simulations are made to ana-lyze the effects on the array gain as a line array is distorted into a circle array. Finally the relationships between signal gain, noise gain and array gain in different directions of signal arrival are given in the case of the real array shape known or unknown.