Help me design a balance PIFA antenna in HFSS

Hi,

Kindly help me. I m designing a Balance PIFA antenna in HFSS for GSM and UMTS (1900,2100).


Q1
How to feed a Balance PIFA antenna ?

Q2
No current flows from my Patch,But gives a good Bandwidth and gain. Why no current flows ?

Q3
How to match the PIFA antenna impedance without changing the position of feed?

I m v.thankful. Hope for prompt replay. Followings are my designs images:-