modify1.m

来自「电磁场圆极化」· M 代码 · 共 64 行

%调幅波,包络线的形成
%copyright 属于研学论坛bbs.matwav.com和plasma

clear all;
omega0=1.e+3;%1MHz
%delta_f=1.e+5;%100kHz
delta_omega=omega0/100.;
light_c=3.0e+8;
mu=4*pi*1.e-7;
epsilon0=1.e-9/(36*pi);
epsilonr=4;
epsilon=epsilonr*epsilon0;
sigma=.01;
cc1=1+sigma/(omega0*epsilon)^2;
beta0=omega0*sqrt(mu*epsilon/2.)*sqrt(sqrt(cc1)+1);
nambla=2*pi/beta0;
delta_nambla=nambla/100;
delta_beta=2*pi*delta_nambla/nambla^2;
delta_t=.01;
%vp=omega0/beta0;%相速度
vg=light_c*omega0^2*sqrt(cc1+sqrt(cc1))/(omega0^2*(1+cc1)+2*omega0^2*sqrt(cc1));%群速度；
vg=vg*0.5*1.e+3;
vp=vg*2.;
E0=1;
t=0;
jmax=300;%100比较合适


for j=1:jmax

    E(j)=2*E0*cos(t*delta_omega-delta_beta*vg*t)*cos(omega0*t-beta0*vp*t);
    E1(j)=2*E0*cos(t*delta_omega-delta_beta*vg*t);
z=1*delta_t*vp:delta_t*vp:jmax*delta_t*vp;
z1=1*delta_t*vg:delta_t*vg:jmax*delta_t*vg;

    hh1=plot(z(j),E(j),                'MarkerFaceColor','r',...
                    'MarkerEdgeColor','k',...
                'MarkerSize',50);
             set(hh1,'Marker','o') ;
             set(hh1,'MarkerSize',18);
hold on;
t=t+delta_t;
z=1*delta_t*vp:delta_t*vp:j*delta_t*vp;
z1=1*delta_t*vg:delta_t*vg:j*delta_t*vg;
axis([1 jmax*delta_t*vp -2*E0 2*E0])
plot(z,E,    'Color','red',    'LineWidth',2);

hold on;
plot(z,E1,    'Color','blue',    'LineWidth',2.5);
hold on;

    hh2=plot(z(j),E1(j),                'MarkerFaceColor','b',...
                    'MarkerEdgeColor','k',...
                'MarkerSize',50);
             set(hh2,'Marker','o') ;
             set(hh2,'MarkerSize',18);

hold off;

getframe;

%pause(0.1);
end