I have a GPS through-hole patch antenna, the through hole need to be connected to the bottom layer and then from there the feed-line flows to the GPS receiver. But I want the GPS receiver to be on top to be facing the sky so that means adding vias on the feed line which will change impedance, right?
I also have a question about the antenna ground plane since I'm a beginner in that field. My PCB is 4 layer with gnd plane as 2nd layer, can I use that as ground plane for the antenna or does the gnd plane of antenna has to be on the top layer directly underneath the antenna?