fdtd s parameter

hi to all,

i need to obtain s parameters from 2d and 3d fdtd simulation .
what is the procedure that i need to follow.

hi dear freind,
in the first time, you have to calculate the electric field magnitude with a simple line of excitation (feed line only), this represent the incident field. after you put the patch antenna (radiator element) on jonction with the feed line, and calculate the new magnitude of the electric field at the junction. after you have to devide the reflected value by the incident value of the E field at the plan(junction).