Patch Antenna at 5GHz using Hfss

Hello
I designed a patched antenna to resonate at 5GHz using HFSS but the problem is when i fed it using Lumped port the frequency shifted by one GHz and if i used wave port the result is good ...

Please Can anyone help me to knew why does this happened ?

Thanks in advance

what type of feeding are you using? coaxial feeding or the microstrip line feeding?

microstrip line feeding

then you should use lumped port for your excitation because wave port is used if coaxial feeding and lumped port is used in microstrip line feeding.

i hope it will help you.

yes I used lumped port but the results are shifted ... i dont knew why ?

is there any modification in Radiation boundary i made it as i did in wave port .. is that right ?

i do not think radiation boundary will leave any effect.?

when i used wave port i defined radiation boundary as BOX and it touch the wave port in same surface ... so i changed the port so i should change the radiation boundary

right ?