基本问题

如何通过不同的表达形式得到一维线阵的同一个方向图？

源代码

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%        函数功能：得到8线阵的方向图%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%clc; clear all;close all;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               参数设置%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%c=3e8;       % 光速f=500e6;     % 信号频率lamda=c/f;   % 波长d=lamda/2;   % 阵元间距N=8;         % 阵元个数theta0=0;    % 波束指向角度bujing=0.1;theta=-90:bujing:90;   % 扫描角取值范围n = [0:1:N-1]'; % 列矢量%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               权值计算%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%W = exp(1j*2*pi*f*n*d*sin(theta0*pi/180)/c); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               法1%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% for p=1:length(theta) % 扫描角取值范围         V = exp(1j*2*pi*f*n*d*sin(theta(p)*pi/180)/c);% 方向矢量     B1(p) =W'*V;   % 阵元功率叠加    '表示共轭转置   .'表示转置      endF1=abs(B1);             % 取信号的模F1=20*log10(F1/max(F1));% 归一化%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               法2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%for p=1:length(theta) % 扫描角取值范围             B2(p) =sum(exp(1j*2*pi*f*n*d*(sin(theta(p)*pi/180)-sin(theta0*pi/180))/c));   endF2=abs(B2);% 取信号的模F2=20*log10(F2/max(F2));%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%               法3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% for p=1:length(theta)    % 扫描角取值范围    t(p)=pi/2*(sind(theta(p))-sind(theta0));   B3(p) =sin(N*t(p))/sin(t(p));    endF3=abs(B3); %取信号的模F3=20*log10(F3/max(F3));% F3=F3/max(F3);figure(1)plot(theta,F1,'-r*');hold on;plot(theta,F2,'-g^');hold on;plot(theta,F3,'-bo');grid on;xlabel('角度/度');ylabel('方向图');axis([-90 90 -50 0]);legend('法一','法二','法三');