Qi charging and nRF52832 antenna

[Gregor14]

I have developed custom PCB with nRF52832. My antenna layout is very similar to layout present on nRF52DK (PCA10040). All works well. Now, in next prototype, I want to add coil for Qi charging (receiver) with dedicated IC. Due to very limited space, coil will be very close to BLE antenna (see picture).

Some parameters: Coil with diameter 19mm is stick at bottom side of PCB. Here on picture shield is square with side 20mm, but I can (and probably I will) extend it to whole board, except of course empty space where is placed antenna for BLE. Shield with thickness 0,1mm and permeability 200 or more. I'm not using NFC.

I can accept problems with BLE communication during charging. My most important question is about reliability. If I use such solution, is there risk to damage nRF chip or other component on board?

regards, Gregor

[Andreas]

Hi,

 

We do not have extensive experience on Qi chargers so I can not say for sure, but it should be fine. The charger will probably generate some noise, unknown what amount at this frequency but as it is placed this close it might not be too severe to possibly block incoming signals.

It will be important though to tune the device when placed on the charger, to account for detuning by the charger and antenna, but if you make sure that the antenna has a good ground plane, either in the top or bottom layer (or both) it should be fine. In any case this will only reduce the maximum range, it will still communicate at ranges shorter than this, so if your requirement is not too high this should also be fine.

 

Best regards,

Andreas