f1=1;
f2=39;
f = Sdb(f1:f2,1);
S1=Sdb(f1:f2,2);
S2=Sdb(f1:f2,3);
S3=srr_P(f1:f2,2);
S4=srr_P(f1:f2,3);
>> s1=10.^(S1/20);
s2=10.^(S2/20);
s3= S3*180/pi;
s4= S4*180/pi;
>> ss3=s3*pi/180;
ss4=s4*pi/180;
s11 = s1.*exp(j*ss3);
s21 = s2.*exp(j*ss4);
lambda=0.3./f;
k=2*pi./lambda;
d=(2.5)*1e-3; %表示2.5乘以10的负3次方，d为介质板厚度
>> figure;
plot(f,abs(s11)); hold on; grid;
plot(f,abs(s21),'r');
xlabel('Frequency [GHz]');ylabel('Magnitude of S');
title('Magnitude of S v.s. f');
legend('S_1_1','S_2_1');
axis([f(1) f(length(f)) 0 1]);
alpha=(1-s11.^2+s21.^2)./(2*s21);
n=(1./(k*d)).*acos(alpha);
for gh=1:length(n)-1
n(gh)=n(gh)*sign(imag(alpha(gh)));
end
n=(real(n))+j*abs(imag(n));
>> figure
plot(f,real(n)); hold on;
plot(f,imag(n),'r');
xlabel('Frequency [GHz]');ylabel('n');
title('Propagation Index v.s. f');
legend('Re(n)','Im(n)');
axis([f(1) f(length(f)) -6 10]);
z=-sqrt(((1+s11).^2-s21.^2)./((1-s11).^2-s21.^2));
z=abs(real(z))-j*abs(imag(z));
>> figure
plot(f,real(z)); hold on;
plot(f,imag(z),'r');
xlabel('Frequency [GHz]');ylabel('Impedance');
title('Impedance v.s. f');
legend('Re(z)','Im(z)');
axis([f(1) f(length(f)) -2 2]);
>> mu=n.*z;
figure;
plot(f,real(mu));hold on;
plot(f,imag(mu),'r');
xlabel('Frequency [GHz]');ylabel('\mu');
title('\mu v.s. f');
legend('Re(\mu)','Im(\mu)');
axis([f(1) f(length(f)) -10 15]);
>> epsilon=n./z;
figure;
plot(f,real(epsilon)); hold on;
plot(f,imag(epsilon),'r');
xlabel('Frequency [GHz]');ylabel('\epsilon');
title('\epsilon v.s. f');
legend('Re(\epsilon)','Im(\epsilon)');
axis([f(1) f(length(f)) -20 3]);
figure;plot (f,imag(alpha),'r'); hold on ;plot (f,real(alpha)); grid;
plot (f,acos(alpha),'k');
figure;
plot(f,phase(-s11)); hold on;grid; %由于相位差180，所以改为-s11.
plot(f,phase(-s21),'r'); %由于相位差180，所以改为-s21.
xlabel('Frequency [GHz]');ylabel('Phase of S');
title('Phase of S v.s. f');
legend('S_1_1','S_2_1');
axis([f(1) f(length(f)) -5 2]);