I have a PCB design which incorporates a GPS unit. I'm looking at refining the PCB, and I'm looking to do away with the long cable length, occupation of space within my enclosure, current consumption, and reliability issues that I have experienced with using an external GPS antenna. I'd like my new PCB design to incorporate a ceramic GPS patch antenna right on the PCB itself.
I have quite a bit of PCB real estate that will be facing the sky once installed in it's enclosure. I'm hoping the enclosure itself won't block the GPS signals too badly, as it is made of plastic that's about 3mm thick.
I know that in order for a ceramic patch antenna to be effective, I need to place a ground plane underneath it. I'm planning on allotting a 40mm x 40mm ground plane underneath the patch antenna, but I'm wondering this:
Can I have part of the antenna ground plane located underneath another small pcb that is mounted on top of the PCB with the ground plane on it?
Here are the specs for the hardware I am proposing:
-PCB antenna ground plane is 1oz per sq ft (1.37 mm) thick
-SIM908 GSM/GPS module from SimCom
-YAGEO ANT1818B00DT1516S GPS patch antenna
Also, a pretty newb question:
Do I connect the antenna ground plane to the ground of the entire PCB? If so, where should this connection be made?