media.m

来自「自由空间E和H场的相位差和振幅衰落」· M 代码 · 共 41 行

clear all
% Parameters for different media
% free space:        kr=1, ki=1, phi=0
% plasma medium:     kr=0, ki=1, phi=pi/2
% very lossy medium: kr=1, ki=1, phi=pi/4
kr  = 1*1;
ki  = 1*1;
phi = 1*pi/4;
xmax = 15;
xmin = -4;
delx = 0.1;
x  = [   0:delx:xmax];
x2 = [xmin:delx:xmax];
framemax = 48;
M = moviein(framemax);
set(gcf,'Position',[100 100 640 480])
for n=1:framemax
E = exp(-0.3.*x.*ki).*cos(kr.*x-2*pi*n/framemax    );
H = exp(-0.3.*x.*ki).*cos(kr.*x-2*pi*n/framemax+phi);
S = E.*H;
figure(1)
whitebg([1 1 1]);
plot(x, E                ,'r'  ,'LineWidth',5);
hold on
plot(x-round(100*H)/30,-H,'b'  ,'LineWidth',3);
plot(x, S                ,'g'  ,'LineWidth',3);
legend('E-field','H-field','Power density')
plot(  x2,   0*x2,'k','LineWidth',3);
plot(  x2, 0.3*x2,'k','LineWidth',3);
plot(0*x2,     x2,'k','LineWidth',3);
hold off
axis([-4 10 -1.1 1.5])
title('Wave Propagation in Very Lossy Media','fontsize',18)
M(:,n) = getframe(gcf);
end
clf reset
set(gcf,'Position',[100 100 800 600])
axis off
movie(M,3,1)
close all