Realized gain and directivity

[xanadu25]

The simulation results shows 4-6 dBi directive gain and -12 to -25 dB Realized gain for the whole band of a dual fed antenna.
Will it work? or how to increase the Realized gain?

 

[Azulykit]

I just responded to this question and I note that so did Vphone. I don't see a need to try to answer it again.