Re: cicular patch antenna
Board is 2.1 by 2.1 inches, ground plane on back. Metal square on the top is 1.65 x 1.65 inches. Hole is offset in top square, along the center in X axis, and 0.305 inches down from the top of the metal square in the Y axis. Material appears to be G10, and is around 0.059 inches thick. There is a 0.125 by 0.125 inch 45 degree chamfer missing from the left top and right bottom of the metal square. Antenna works at 2.45 GHz, so you will have to scale things larger for your frequency band.
I have no clue if it is RH or LH circularly polarized, but is one of those.