I have designed a vehicle tracker for two-wheelers which is installed in 500 bikes. I am facing an issue with GPS performance (lock percentage is quite low for more than 75% bikes). This makes me question 2 possible things:
- GPS antenna quality from the vendor
- PCB design of RF part of GPS module
For the first part, I have asked the vendor to share the RF performance and quality check report with me. In the meantime, I want to make sure that the RF design part on PCB is not impacting the performance.
Following is the snap of my GPS RF design part:
As shown in the design:
- I have tried to put as many vias as possible around the RF part
- RF trace width is calculated using microstrip width calculator
- I have avoided putting any power trace near the RF antenna part and separated the ground plane.
I am using an external GPS antenna (through U.FL to SMA converter) which is placed under the front panel of bike (which is made of plastic).
Based on this, I have a few questions which might impact the performance:
- U.FL connector is placed at the edge of PCB. Is it creating any kind of issue?
- I have GSM antenna and module placed very close to GPS, which might hamper the performance (though I have tried my best to separate out the GND planes of these modules)
- Any other inputs/thoughts based on your RF experience will help me a lot.