This is defiantly homemade design. I have one small antenna whit only 4 dipoles - and it works great, so this antenna should work fine. Also will be easy to be rescaled for other bands - 2.4Ghz or 5Ghz only change dimension of the dipoles.
19dbi panel wifi antenna link to picture
Here is the photo from the other side of the pcb board and other part of feeding element
Picture is from this address : diy.wifi-live.pl/node/4 where also have blueprints for less dbi antenna .
On www.zero13wireless.net also has several files posted by sushisan .
Link to files 18dbipcbdipoleantenna.zip