Xfdtd Microstrip line..Help Please!!

Hello Everyone,

I am trying to simulate a microstrip Rf coil at 123.48 Mhz in Xfdtd. But, the S11 is very bad. I got good result with Ansoft HFSS ( FEM based) and Semcad (FDTD based) with the same structure. I do not know why s11 is different in xfdtd.

I tried gaussian pulse for the excitation and so that I can see the S11 curve. I just wonder whether there is any problem with meshing /excitation/geometry. Can anyone please help me in this? I attached the xfdtd file for the convenience.

Thanks in advance.