function s = setphase(si,az,el,freq)
% s = setphase(si,az,el,freq)
% Sets the optimum phases in a phased array antenna si for radiation 
% in the direction given by az and el.
% si :   Structure of the phased array antenna
% az :   Azimuth angle in degrees
% el :   Elevation angle in degrees
% freq : Frequency in MHz
% s  :   Antenna structure with optimum phases (s = si is allowed).
