The sketch I made during a three day technical training related to GNSS (GPS, Glonass, Beidou, Galileo, QZSS). The PCB can be even smaller, but this will minimise the efficiency of the antennas. The GPS chip antenna would like to have a ground plane of 22,5 mm left and 22,5 mm right. 22,5 mm x 2 x 40 mm means 1800 mm2 ground plane for the GSM antenna. Nevertheless, I can make it even smaller, but I canÂ´t cheat the physics.