cal_e_field_dipole.m

Calculate E-field of dipole antenna.

%=======================================================                                 
% Msc Antenna and Propagation Assignment Problem 2:
% Write a program to determine the far field electric field strength of a dipole.
%=======================================================
% Programer: Yen-Ju Huang
% Date: 30-11-2008
% Version: 0.1
% Location: Leeds, UK
% State: Finish Draft
%=======================================================
clear all;
close all;

disp(' ');
disp('> This program can be used to calculate the far field strength of a dipole. ');
disp(' Please input the following parameters to gain the result. Thanks. ')

% user inputs parameters
disp(' ');
Rf=input('> Input Radio Frequency f (MHz): ');
Dist=input('> Input the Distance which is how far from antenna D (km): ');
Im=input('> Input the Current Im (A): ');
Theta=input('> Input the Elevation Angle theta (Degree): ');
H=input('> Input the H parameter which is a half of antenna length, (labda): ');

% modify and calcuate parameters
Rf=Rf*(10^6);                                   % Hz
Dist=Dist*(10^3);                             % Metre
Theta=deg2rad(Theta);                       % radian

Labda=(3*(10^8))./Rf;                       % find wave-length
H=H*Labda;

Beta=2*pi./Labda;

% caclulate far field strength (mV/m)

E_Field=(i*60*Im*exp(-i*Beta*Dist)./Dist)*((cos(Beta*H*cos(Theta))-cos(Beta*H))...
    ./sin(Theta));

Res_E=abs(E_Field)*(10^3);

% output the result
disp(' ');
disp(['> The result of far field strength is (mV/m): ', num2str(Res_E)]);
disp(' ');