I would like to prototype a patch antenna at low cost for a project. The PCB vendor (Seeed studio) that I prefer uses KB-6160 FR4 laminate which does not have dielectric constant data beyond 100 MHz.

Does anyone have any experience prototyping patch antennas on FR4?
Is 4.2-4.3 a good estimate of the dielectric constant around 2.4 GHz? Or is it too optimistic to assume a controlled value?
Any recommendations for getting cheap prototypes on Duroid?

Thanks!

 

The thickness of a PCB is wrong for that freq.
It works, but you could get MUCH better performance using PTFE or just air.
.04 x wavelength is a proper spacing that will give good performance. PCB thickness gives less than .02 x wavelength.

Lots of good design write ups could be found by searching the web.