directivity.m

patchantenna matlab code

function [direct, directdB, Prad]=directivity(phiMin, phiMax, thetaMin, thetaMax, fr, width, Leff, h)

% This MATLAB file was created by Gazi K Asadullah
% width = width of microstrip Antenna
% Leff = Effective length of Microstrip Antenna
% h = Thickness of Microstrip Antenna
% phiMin= minimum angle for E plane radiation
% phiMax = Maximum angle for E plane radiation
% thetaMin = Minimum angle for H plane radiation
% thetaMax = Maximum angle for H plane radiation
% fr= Resonant Frequency
% This function will use the function called radiation_intensity.m and calculates
% the total radiated power and directivity of Patch Antenna.
% Reference:
% Antenna THeory: Analysis and Design: by Balanis (chapter 14)





Umax=0;
%Converting to mm from inch
width= width*25.4;
Leff=Leff*25.4;
h=h*25.4;

Umax=0;
d_theta=pi/180;
d_phi=pi/180;
Prad=0;
phiMin1=phiMin+1;
%double integration
for phi = phiMin1:phiMax
    phi_rad=phi*pi/180;
    thetaMin1=thetaMin +1;
    for theta=thetaMin1:thetaMax
        theta_rad=theta*pi/180;
        radiation = radiation_intensity(fr ,theta_rad, phi_rad, width, Leff, h);
        if radiation > Umax
            Umax=radiation;
        end
        UA= d_theta* d_phi * radiation*sin(theta_rad);
        Prad=Prad+UA;
    end
end
    direct= 4*pi* Umax/Prad;
    directdB=10*log10(direct);