Design antenna in ADS

Hi,
Can anyone help me?
I design ZOR antenna in ADS with resonance frequency is 915MHz.But in my design i don't see the resonance frequency. This is my design http://www.mediafire.com/?b0gt1cbg3ey5n42
thanks !
i'm sorry but i can't upload my file in this thread

sorry, i don't understand what's your mean. can you talk more detail?

Entry was wrong.Sorry..

no anyone help me?