When designing the Printed Circuit Board (PCB) layout, pin-specific
recommendations should be followed.
The GPS pin has the following recommendations:
- To ensure good, radiated performance, begin the design by locating the Global Positioning System (GPS) antenna on the PCB.
- Ensure preliminary antenna performance on a chosen PCB location, for example, by
simulation.
- When multiple antennas, for example, LTE, GPS, and Bluetooth®
Low Energy are
present, minimize antenna crosstalk.
- Antenna transmission line impedance should be 50 Ω. Take this into account when selecting the
PCB stack-up.
- Avoid excessive capacitance in routing by opening ground layers under component pads. For
example, if the routing is on the top PCB layer, open the ground plane under the
GPS pad on the next metal layer.
- When opening ground planes, avoid exposing noisy routings under the GPS pad.
- Avoid long routing because it causes excessive insertion loss which deteriorates RF
performance which cannot be reversed.
- Ensure continuous reference ground plane above, below, or both of the GPS
routing.
- Consider adding a test connector to the antenna path for production test and diagnostic
purposes. Ensure that the test connector or solution does not deteriorate the impedance of the
transmission line.