Help me build a simulation for Yagi antenna in HFSS

CAN SOMEBODY PLEASE HELP ME IN BUILDING A SIMULATION FOR YAGI ANTENNA IN HFSS FOR GSM BAND i.e 900Mhz and 1800Mhz.

i can give you some information but only for ADS momentum..so in case you decide to design it using ADS i can tell you about

plz check the errors in this design it is giving only .2db gain at 900Mhz