I am desigining UWB antenna with ecllipse shaped patch on HFSS.Why gain is coming negative ?

I am attaching my design and result of Gains.S11 parameter is less than -10dB from 3.1 to 9.8 Ghz.Z11 magnitude also lies between 40 -60 ohm for this range .Still gain is negative. Pls help

30 January 2021 4,545 3 View