% Figure 2.17
% figure 2-15
% calculate the fresnel coefficients for Parallel polarization

epsr=2;
thetat=asin(sqrt(1/epsr)*sin(theta));

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

epsr=8;
thetat=asin(sqrt(1/epsr)*sin(theta));
den=cos(thetat)+sqrt(epsr)*cos(theta);
g3=(cos(thetat)-sqrt(epsr)*cos(theta))./den;
T3=(1+g3).*cos(theta)./cos(theta);

epsr=32;
thetat=asin(sqrt(1/epsr)*sin(theta));

den=cos(thetat)+sqrt(epsr)*cos(theta);
g4=(cos(thetat)-sqrt(epsr)*cos(theta))./den;
T4=(1+g4).*cos(theta)./cos(theta);
figure;
subplot(2,1,1)
plot(ang,abs(g2),'k',ang,abs(g3),'k',ang,abs(g4),'k')
text(20,.22,'\epsilon_r_2 = 2');text(30,.49,'\epsilon_r_2 = 8');text(40,.69,'\epsilon_r_2 = 32')
xlabel('\theta')
ylabel('|R_|_||')
%legend('\epsilon_r_2=2','\epsilon_r_2=3','\epsilon_r_2=4',2)
title('Reflection Coefficient')
axis([0 90 0 1])
%grid on
subplot(2,1,2)
plot(ang,abs(T2),'k',ang,abs(T3),'k',ang,abs(T4),'k')
text(35,1.05,'\epsilon_r_2 = 2');text(42,.75,'\epsilon_r_2 = 8');text(50,.55,'\epsilon_r_2 = 32')
xlabel('\theta')
ylabel('|T_|_||')
%legend('\epsilon_r_2=2','\epsilon_r_2=3','\epsilon_r_2=4',2)
title('Transmission Coefficient')
axis([0 90 0 2])
%grid on