MATLAB: Received Power Vs Distance

@aj

Hi Everyone;

My MATLAB code result in the received power increases with distance as shown in the figure in spite I use Friis formula. Where is my mistake.

Pr=Pt*Gt*Gr*lambda^2./16*pi^2.*(Z).^2; %Friis Formula

If Z is distance then you should probably have

Pr=Pt*Gt*Gr*lambda^2./(16*pi^2.*Z.^2);

Note the position of the parentheses. In your version Z is on the numerator.

like in the pictures but juste one pick

k = 5:5:50;
Pr1 = (10*0.75*0.75*(exp(-0.984*k./cos(pi/36))) .* 0.01 .* cos(pi/36) ./ ((2*pi*k.^2)*(1-cos(pi/3))));
z=10.*log10(Pr1);
plot(k,z,'-*')