function demoAntenna
%
%      This demo computes and displays the antenna gain of
%      the ITU699-1 antenna, Required for the analysis of
%      inteference into ground based microwave systems
%

D       = 2.76; % [m]
lambda  = 0.12; % [m] corresponding to f=2.5 GHz
Gmax    = 33;   % [dB]
i = 1;
G = 1;
x = [0:.2:2.8 2.8276 3.2983 3.5:.5:90];

for phi=x,
  G(i) = ITU699_1(phi, D, lambda, Gmax);
  i    = i+1;
endfor

Aeff = exp10((G +10*log10(lambda^2/(4*pi)))/10);
erase

plot(x, Aeff, 'logy,grid')
title('ITU 699-1: D=2.76m, l=0.12m, Gmax=33',
      '                 l  g     l      lll')
ylabel('Effective Antenna Area (m223)',
       ' llllllll  llllll lll slx xs')
xlabel('f (deg)',
       'g sllls')