antenna design using fdtd

Hi everybody,

I am writting a final year thesis on antenna design and simulation using fdtd code implemented in C/C++, but i am having problems. I don't know how to incorporate my two dimensional planar antenna into the simulation space. Can anybody tell me how to do this, i.e 1) Descretize the planar antenna, 2) inject a voltage pulse at the terminals of the antenna and determine the current distribution on the antenna.
Thanks in advance.

Babs