Help me with FDTD near to fare field transformation

Hi everybody,


I have written an fdtd code and Have gotten result that I need, but I have a problems with understanding the near to far field transformation implementation in fdtd.I have read taflove book: Computational electrodynamics, the finite difference time domain method, publication of Luebbers on near to far field transformation and sullivan's book on electromagnetic simulation using fdtd, BUT i still have problem understanding the method.

My question is THIS: in evaluating the current densities on the virtual surface, how do I estimate the value of "f" in the superscript of the value of U(i.e the electric vector potential) or more precisely, how do i estimate the phase delay (tau subscrip d) and inco-orporate it into the progarm.

PLEASE: if anyone have a 3D near to far field transformation in FDTD, I will be very grateful if that person can post it. I NEED IT URGENTLY PLEASE. Thanks.
babs

plz could your program calculate the transmission or reflectance through waveguide?

No, not yet.I have only developed it recently and applied it to a bow-tie antenna simulation using matlab.

Plz let me know when you could calculate the transmission or the reflectance

You can consult Taflove's book, chapter on near to fare field transformation

just set "f" as a constant,for example the data output boundary size is 7*7*37,so i select f = 50,finally i get the correct result.mybe there is some way to estimate the value of "f",but i did not know.you can try it! good luck!

Added after 7 minutes:

u also could set 'f' as a 'real' value,for example the observation point have '100' wavelength away from source point.so f=100*WL/(c*delta t)