zoukankan      html  css  js  c++  java
  • 泰勒离散线源综合-更正

    修改好的matlab程序

     1 function I = taylor_line(N, SLL)
     2  
     3 M = 10000;
     4 d = 1/2;
     5 L = (N)*d;% antenna length 
     6    theta = 0:pi/M:pi;% 
     7 %  theta = linspace(-pi/2,pi/2,M+1)
     8 x = L*cos(theta);
     9 f0 = 1e9;
    10 %lambda = 3e8/f0;
    11 %d = lambda/2;% elements spacing
    12 k =2*pi;% wave constant
    13 R = 20; % amplitude ration between mainbeam and sidelobe , dB
    14 A = acosh(10^(-SLL/20))/pi;
    15 % T = cos(pi*sqrt(x.^2-A^2));
    16 % af = 20*log10(abs(T)/max(T));
    17 % error = 0.001;
    18 % % af=U;
    19 % pos1_3dB = [];
    20 % pos_max = find(max(af)==af);
    21 % while(isempty(pos1_3dB))
    22 %     pos1_3dB = find(abs(((af(1:pos_max)-af(pos_max)))+3) < error);
    23 %     error = error + 0.001;
    24 % end
    25 % error = 0.001;
    26 % pos2_3dB = [];
    27 % while(isempty(pos2_3dB))
    28 %     pos2_3dB = find(abs(((af(pos_max:end)-af(pos_max)))+3) < error);
    29 %     error = error + 0.001;
    30 % end
    31 % BeamWidth= (theta(pos2_3dB(1)+pos_max)-theta(pos1_3dB(end)))/pi*180;
    32 % figure;
    33 % plot(theta,af);
    34 % hold on;
    35 % str = strcat('L=', num2str(L),'lambda, SLL = -',num2str(R) ,'dB ');
    36 % bw = strcat('mainbeam beamwidth=',num2str(BeamWidth),'degree ');
    37 % text(pi*2/3,-5,str,'fontsize',12);
    38 % text(pi*2/3,-8,bw,'fontsize',12);
    39 % title('Radiation Pattern of an Idealized Equvialent Sidelobe Array ');
    40 % xlabel('Phase');
    41 % ylabel('Amplitude');
    42 % ylim([-60 0]);
    43 %%
    44 % Taylor synthesis
    45 % theta = -pi/2:0.01:pi/2;% 
    46 % x = L*cos(theta);
    47 
    48  n1 =ceil(A^2*2+0.5);% the first 3 sidelobes have almost same amplitude
    49 %   n1 =4;
    50 %I=taylorwin(N,n1,SLL);
    51 sigma = n1/sqrt(A^2+(n1-0.5)^2);
    52 xn = zeros(1,n1-1);
    53 for j = 1:1:n1-1
    54  xn(j) = sigma*sqrt(A^2+(j-0.5)^2);
    55 %  xn(j) = j*sqrt(A^2+(j-0.5).^2)/sqrt(A^2+(n1-0.5).^2);
    56 end
    57 for i = 1:1:length(x)
    58     if x(i) ~= 0
    59         T(i) = sin(pi*x(i))/pi/x(i)*cosh(pi*A);
    60         for j = 1:1:n1-1
    61         T(i) = T(i)*(1-(x(i)/xn(j))^2)/(1-(x(i)/j)^2);
    62         end
    63     else
    64         T(i) = cosh(pi*A);
    65         for j = 1:1:n1-1
    66         T(i) = T(i)*(1-(x(i)/xn(j))^2)/(1-(x(i)/j)^2);
    67         end
    68     end
    69 end
    70 T = T / max(T);
    71 
    72 I =ones(1,N);
    73 % zn = zeros(1,N);
    74 for i = 1:1:N
    75      if mod(N,2) == 1
    76         zn = abs((i-(N+1)/2)*d*2/L);
    77      else
    78         %#zn = (i-(N+1)/2)*d
    79         if i < (N+1)/2
    80             zn = (2*abs((N/2+1)-i)-1)*d/L;
    81         else
    82             zn = (2*abs(i-N/2)-1)*d/L;
    83         end
    84      end
    85     for j = 1:1:n1-1
    86 %          I(i) = I(i) + 2*T((find( min(abs(x-j))==abs(x-j))))*cos(j*pi*zn);
    87           tmp = power(prod(1:(n1-1)),2)/prod(1:(n1-1+j))/prod(1:(n1-1-j));
    88         for k = 1:1:n1-1
    89             tmp = tmp* (1-j^2/sigma^2/(A^2+(k-0.5)^2));
    90         end
    91           
    92           I(i) = I(i) + 2*tmp*cos(j*pi*zn);
    93     end
    94 end
    95  I = I/max(I);
    96 
    97 end

    对于N=10,SLL=-30,综合结果如下:

  • 相关阅读:
    hdu 2196(树上点分治)
    hdu 4807(网络流 + 贪心)
    hdu4101
    hdu4216
    hdu 4219, 树形概率DP
    hdu 4127 A*搜索
    hdu 4126
    hdu 5296,15年多校1-7
    poj3436 ACM Computer Factory
    Fence
  • 原文地址:https://www.cnblogs.com/hiramlee0534/p/6993300.html
Copyright © 2011-2022 走看看