HI
I try also to simulate the near field far field transformation with FDTD, for the analysis of a p.a.t.c.h microstip antenna to obtain the radiation pattern.
I found many difficulties specially to understand the steps to follow to do this transformation.
Could anyone help me ??
In order to determine the radiation pattern at a point of frequency, freq.domain near-to-far-field transformation technique is more useful, easier and more memory-efficient than time-domain technique.
Using real-time DFT technique, equivalent surface current on the virtual surface surrounding antenna will be calculated. I reccomend you FD-technique because microstrip antenna is narrow band antenna.