Congratulations for your work, I also work on this topic...
I've been reading your file very fastly.. I think your antenna works in Linear Polarization doesn't it? I want to know if you have tried the dual frequency concept in a CP patch antenna..
I want to design a dual rectangular patch antenna each having 2 coaxial feed and those feed shld be 90 degree out of phase and those 2 antennas may be on the same pcb...
kindly tell me how to excite those 2 antennas for diff frequencies..how to simulate...am using ie3d software