different resultat in simulation with ads and HFSS

hello

I've simulated an antenna in ads and I've got I minimum of -30 db , this afternoon I made the same design but in HFSS and I used a lumped port but I had only a minimum of -4 db with a shitf of frequency (about 30 MHZ) I don't know where is the error. Has anyone met the same probleme before?

I need your help