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Layout for GNSS Module

Posted: 13 Jul 2024, 16:59
by technoid23
Hello,
Hoping to get some help with a board layout. I'm using a Ublox CAM-M8C with an integrated chip antenna, but it's not acquiring a fix. All connections are OK, power supply is noise free. The board stack up *recommended* is in section 2.6 page 13 of this manual:
https://content.u-blox.com/sites/defaul ... 063%29.pdf

I didn't follow that, my stackup is:
TOP - copper pour fill and traces
GND - full ground plane
PWR - power traces only with copper pour fill
BOTTOM - copperpour fill and traces

Below the GNSS antenna is a keep-out as recommended by layout guide on all layers. No vias or traces anywhere. I can only assume at this point that the layout is the problem. Does anyone with layout experience in these modules know if this is the issue, and why? If I were to tie the copper pour to GND would this help the problem? I've attached a screen cap of the module section.

Thanks for your help.

Re: Layout for GNSS Module

Posted: 17 Jul 2024, 22:42
by Roli
The Copper Pour has to be GND. It is a Part from the antenna. And it is important that the Copper Pour on L2 is full GND with no traces around the Antenna.