关键参数设置

     假设波束指向角度为40度，权值所用频率为500MHz，方向矢量所用频率分别为450MHz，500MHz，600MHz。

源代码

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%              线阵(孔径效应)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
clc;
clear all;
close all;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%               参数设置
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
c=3e8;                 % 光速
fc=500e6;              % 权值所用频率
f=[450e6 500e6 600e6]; % 方向矢量频率
lamda=c/fc;            % 波长
d=lamda/2;             % 阵元间距
M=10;                  % 阵元个数
theta0=40;             % 波束指向取值范围
n = [0:1:M-1]';        % 列矢量
theta=-90:1:90;        % 扫描角取值范围%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%               权值计算
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
W = exp(1j*2*pi*fc*n*d*sin(theta0*pi/180)/c);%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%           权值*方向矢量
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for p=1:length(f)for q=1:length(theta)    % 扫描角取值范围    V = exp(1j*2*pi*f(p)*n*d*sin(theta(q)*pi/180)/c);%接收信号 相对于原点接收到的归一化的信号B(q) = W'*V;       % 阵元功率叠加    '表示共轭转置   .'表示转置end
F=abs(B);    % 取信号的实部
Fmax=max(F); % 得到最大值
F_dB=20*log10(F/Fmax);
plot(theta,F_dB);hold on;grid on;
endaxis([-91 90 -40 1]);
legend('f=450MHz','f=500MHz','f=600MHz');

仿真结果

仿真结果分析

     从仿真结果可以看出，只有当权值所用频率和方向矢量所用频率相等时，波束指向才正确。