Microstrip patch antenna on FR4 for 2.4 GHz band

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 from batch to batch?
Any recommendations for getting cheap prototypes on duroid?

Thanks!

FR-4 has a lot of variation from vendor to vendor. If you can be assured that your vendor uses the same supplier of FR-4, it is fairly consistant from batch to batch. It is not the best to use for RF circuits that need good control of both the dielectric constant as well as the lost tangent. However, it IS used for RF circuits in spite of its weaknesses.

I recommend that you do Monte Carlo type of analysis on your design to see what effect these parameters have on your overall design.

Cheap prototypes on Duroid? Never heard of any.

The points SLK001 mentioned are all correct however for practical design my approach is different: I cut prototype with a knife adjust dimensions until my match is good then order to the shop. It is faster then modeling.

I think studying the spice model in analysis process then set parameter in spice program to more practical and proper for purpose . Pspice has Monte Carlo analysis option , But no 3D graphics result shown .