%聲壓陣波束形成
clc
clear all
clc
f0=500;     %中心頻率為1000Hz
fs=f0*200;    %四倍中心頻率的采樣率 
L=16       %陣元數目
c=1500;     
d=1/2*c/f0;      %陣元間距 
ru=0*pi/180;     %入射信號的方向
t=0.05;      %積分時間
n=0:1/fs:(t-1/fs);
len=length(n);
sub_len=fix(L*L*d/c*fs);
signal_len=len+L*sub_len;
sig_t=0:1/fs:(signal_len)/fs;
r=2;
% xishu=CHEBWIN(L);
xishu=ones(1,L);
%%%%%%%%%%%%%%%%%%%%%%%造入射信號%%%%%%%%%%%%%%%%%%%%%%
for ii=1:L
    sig(ii,:)=xishu(ii)*cos(2*pi*f0*sig_t+2*pi*f0*(ii-1)*d*cos(ru)/c);
end

for thita=-90:r:90
    thita1=thita*pi/180;
    tao=round(d*cos(thita1)/c*fs);
    pp=zeros(1,len);
    for ii=1:L
        p(ii,:)=sig(ii,sub_len+(ii-1)*tao+1:sub_len+(ii-1)*tao+len);
        pp=pp+p(ii,:);
    end
    out((thita+90)/r+1)=sum(pp.^2);
end
figure;
plot([-90:r:90],out);grid on;
figure;
plot([-90:r:90],10*log10(out/max(out)));grid on;
title('常規波束形成');
% figure;
% polar([0:180]*pi/180,out,'--r');