STM32WBA5MMG GND pads near antenna

[robintechnology4u]

Dear all,

I have a custom PCB with the STM32WBA5MMG module. I missed the keepout requirement in the reference design and pads 2 - 5 and pads 56 / 59. These pads are connected to GND in my design. I did some signal tests, and I have a feeling the antenna is not performing well (I configured +10dbm).

Can somebody confirm these pads connected to ground influence the antenna performance? Below is a snippet of the PCB design:

Thanks,

Robin

[XERC · Accepted solution]

Hello, yes clearly the keep out requirement is important to have optimal antenna performance. This should be applied on all layers. This is difficult to estimate precisely what is the real impact in term of performances, but there will be degradation for sure on both Tx and Rx.