uhf rfid simulation

Hi,

I am new to antenna simulation and am looking for a tutorial on UHF RFID tag simulation using HFSS.

In particular, I am looking for a tutorial that demonstrates how to model the antenna, the IC impedance and the kind of port modeling I need to use. Most of the papers I have read discuss the geometry and results but I have not been able to find a useful reference model.

I'd really appreciate it if someone could share a sample / point me to another post which addresses this.

Thanks!