tm_efie.m

TM波照射导体圆柱

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tic
clear
clc
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% 初始化

% 已知条件
wavelength=1.0; %  波长
a=wavelength;  % 令圆柱半径等于波长
               % 为便于处理，令来波方向角为pi,入射角为0

% 常数定义
K=128; % 圆柱截面圆离散点数
dp=2.0*pi/K; % 离散角步长
del=2*pi*a/K; % 离散弧步长
k=2.0*pi/wavelength; % 波数
u0=4*pi*10^(-7);   % 真空磁导率
e0=1/(36*pi*10^9);   % 真空介电常数
ETA=(u0/e0)^(1/2);   % 自由空间波阻抗
gama=1.78107; % 欧拉常数
d=k*ETA/4.0;   %　系数
e=2.718;
% 坐标确定
for m=1:K
    pp(m)=(m-1)*dp+dp/2;
    x(m)=a*cos(pp(m));
    y(m)=a*sin(pp(m));
end

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% 主体

% 阻抗矩阵计算
for m=1:K      % 场点循环
    for n=1:K    % 源点循环
        if (n==m)   % 奇异点处理
            LMN(m,n)=k*ETA/4.0*del*(1-(2/pi)*i*(log(k*gama*del/(4.0*e))));   % 零阶近似
%            
        else
            r=sqrt((x(m)-x(n))^2+(y(m)-y(n))^2);
            LMN(m,n)=k*ETA/4.0*del*besselh(0,2,k*r);   % 零阶近似
%             
        end
    end
end  

% 电压矩阵
for m=1:K;
    GM(m)=exp(-i*k*(a*cos(pp(m))+a*sin(pp(m))));
end

% % 表面电流分布矩阵计算
Jz=LMN\GM.';
disp(Jz)
figure(1)
plot(abs(Jz));
title('电流分布图');