Here are the design files I have so far for the PCB antenna.
One is the kicad footprint for the antenna. Another is the prototype PCB I made and tested.
I exported gerbers from kicad and imported them in IsoPro to make separation cuts with the PCB mill. IsoPro runs on windows and requires a serial dongle for copy protection (rs232!).
I think it would make sense to include a couple of antennas on the lid for WIFI and bluetooth as well. Since bluetooth is 2.4GHz this antenna design should work as well. I have yet to check the performance of 5Ghz vs 2.4Ghz wifi. I believe this antenna should work for both 2.4 and 5Ghz.