microstrip patch antenna design

hello sir/madam

i have designed a rectangular patch antenna with circular polarization,,,,but i exactly dont know to measure axial ratio,,,can u please help me in fingding out axial ratio vs frequency graph,,,
after designing for circular polarization ,if we dnt get axial ratio less hen 3bd,,,is the design wrong?

I recommend you can use a commercial software such as CST or HFSS or ADS. all of them calculate the axial ratio easily and you don not need to do anything.

hi
axial ratio is in this range:0dB<AR
if AR=0dB,have circular polarization,but AR<3dB is acceptable and have elliptical polarization.