simulation microstrip antenna in hfss

hi everybody. i want to simulate mocrostrip antenna that consist of 2 rings. i wonder wether i should use 2 feeds for each ring or not? if yes from which port i should see s11? thanks

If You are focus is on designing Microstrip Antenna i suggest that you should use a Software called ADS by agilent
this software entirely focused on antenna desingn. You can very well see the S11 S21 S31 in it at you can very easily attach ports to it
Just use this software and you don.t need to re design it just transfer the design using export option.

rest if you dont want to use ADS Just simulate the design and you'll get the option for the required results
and S11 is seen from any of the input port
REgards

thanks for your help. but i want to simulate microstrip antenna to use for reflectarray antenna and i know that i can choose a port to see s11 but i dont know that for reflectarray antenna which port i should see.