Wow – dimentions for 28dbi 5ghz wimax antenna are available thanks to : kleiner-onkel from www.carookee.com/forum
more pictures from this antenna here :
http://www.digdice.com/5ghz-28dbi-wimax-pcb-panel-antenna/
5ghz 28dbi wimax wifi antenna dimentions
Link :
Printed on dual sides of 1mm FR4 board.
60 degrees sector.
Price mentioned around 130 euros
I thing that this can be used as omni antenna without the reflector. And can be build with more or whit less dipoles for tests.
5Ghz Sector Wifi Antenna
5Ghz Sector Wifi Antenna schematic