negative gain antenna

[nf707]

hello all
i simulated this antenna in HFSS for circular polarization but the gain of antenna is negative? i intend ask a question whats the negative gain? gain is a positive quality

 

[BradtheRad]

Could there be standing waves in the line?

Your attached graphic didn't open. It's a .rar file. Try again with a jpg.

 

[rntsay]

your gain plots are in dB (-4 to -1 dB), these correspond to gain <1; not negative.

 

[nf707]

hello rntsay
thanks for reply
just a question
How we can improve the bandwidth of axial ratio(for circular polarization)
is it possible we reach 1GHz bandwith CP for this antenna?

 

[rntsay]

sorry but that's well outside what I know. I don't think it's an easy problem
even for experts.