Re: microstrip antenna with microstripline feedin hfss

i am designing a single patch antenna to operate at 10 Ghz the microstrip antenna has the following specfications
length=9.06mm
width=11.86mm
thickness=0.00028mm
substrate height=1.58mm
dielectric constant =2.2
microstip antenna Z=228 ohm
the antenna is matched to a 50 ohm line using a lambda/4 transformer i have calculated the microstrip line widht using the formulas given in book by pozar on microwavw engineering now the problem is the antenna is resonating at 9.5Ghz and the VSWR is more than two can anyone please tell me where am i going wrong ?

Added after 1 minutes:

i have placed the microstrip feed line at the center point of the antennas width

http://www.emtalk.com/mpacalc.php?er...ist=Wmm&Rin=90

http://www.emtalk.com/mwt_mpa.htm

Calculate the size of your antenna from the first link.Consider that the height of the air box should be at least lambda/4.

step by step modify it, You can finish.