I have recalculated Admins 5 Ghz batwing (Page 8) for better SWR if somebody want to make one. I also found that the SWR could be improved if the leg is not touching the reflector, so i added a hole at this place to reduce contact which seems to work. From the calculations the antenna should perform and work very well:   Gain: VSWR + S11:  Dimensions (this thing is tiny ): Impedance: