HFSS Patch Antenna (Please heeelpp!!).

I want to change dimensions of my patch antenna to radiate 1GHz and resistance 50 ohm. I try all the time to change this dimensions but with no result at all.

Sub: x=20, y=18
Patch: x=9.4, y=10.6

I've atached the file here. Pleasee help as soon as possible (urgently!)
mikeAntenna.zip

hi.
I saw your design.
I think,you didn't design patch antenna, in fact you designed reflector ant and this ant excited(feed) by that patch.
ok?