more resonance frequency than wanted on HFSS

hi everyone. i am new at HFSS and trying to simulate a GPS antenna with microstrip patch and feedline. my L1 band frequency simulation results show more than one resonance frequency, that is there is several other frequencies gives resonance. i tried to change feed line witdh and position but it didnt work. how can i supress other frequencies ? is an inset feed design helpful for this problem?
thanks..