% Figure 2.15
% Calculate the fresnel coefficients for Perpindicular polarization

theta = 0:.01:pi/2;
ang=theta*180/pi;
epsr=2;


thetat=asin(sqrt(1/epsr)*sin(theta));
den=cos(theta)+sqrt(epsr)*cos(thetat);
g2=(cos(theta)-sqrt(epsr)*cos(thetat))./den;
T2=(1+g2);

epsr=8;
thetat=asin(sqrt(1/epsr)*sin(theta));
den=cos(theta)+sqrt(epsr)*cos(thetat);
g3=(cos(theta)-sqrt(epsr)*cos(thetat))./den;
T3=(1+g3);
epsr=32;
thetat=asin(sqrt(1/epsr)*sin(theta));
den=cos(theta)+sqrt(epsr)*cos(thetat);
g4=(cos(theta)-sqrt(epsr)*cos(thetat))./den;
T4=(1+g4);
figure;
subplot(2,1,1)
plot(ang,abs(g2),'k',ang,abs(g3),'k',ang,abs(g4),'k')
text(55,.26,'\epsilon_r_2 = 2');text(40,.45,'\epsilon_r_2 = 8');text(20,.65,'\epsilon_r_2 = 32')
xlabel('\theta')
ylabel('|R_\perp|')

title('Reflection Coefficient')
axis([0 90 0 1])
subplot(2,1,2)
plot(ang,abs(T2),'k',ang,abs(T3),'k',ang,abs(T4),'k')
text(55,.76,'\epsilon_r_2 = 2');text(40,.55,'\epsilon_r_2 = 8');text(20,.38,'\epsilon_r_2 = 32')
xlabel('\theta')
ylabel('|T_\perp|')
title('Transmission Coefficient')
axis([0 90 0 1])