On a PCB a GPS patch antenna should be placed. The antenna feed pin goes through the board and is soldered on the bottom side. On the PCB top layer is a ground plane. My problem is now to define the radius of the area around the feed pin that has to be kept ground free to achieve the best signal transmission. See graphic of cross cut.
Can anyone help me with this problem?
Parameters: PCB material FR4, 0.8mm thick. Antenna impedance 50 Ohm, feed pin diameter 0.8mm.