[moved] Microstrip Patch Antenna at L1 in HFSS

I have to design a patch antenna with the following specifications.

Frequency - the GPS antenna bandwidth shall be 1575 MHz +/- 10 MHz
Gain - The GPS antenna shall be no less than 0 dB at the peak of the beam and no less than -5 dB at 10 degrees above horizon for 90% of the pattern
Polarization - The GPS antenna polarization shall be RHCP
FoV - The GPS Antenna shall be upper hemispherical
VSWR - The GPS VSWR shall be no greater than 2:5:! in reference to a 50-ohm system

I have attached the antenna along with picture results that I simulated to try and reach these specifications using HFSS

I understand how to meet the gain and frequency specifications. However, I do not understand how to obtain an RHCP polarization or checking the input impedance of my simulations. I wiould like to check these parameters in HFSS via results. Thank you!

I also need help on doing a dielectric constant parameter sweep on the S11 frequency plot.