Antenna design check nRF52840 custom board

RE: Antenna design check nRF52840 custom board

Andreas — Thu, 02 Jul 2020 06:39:36 GMT

Hi,

I would start with the one in the reference layout (v1.1), that generally has a bit more margin on harmonic emissions. It is hard as you say to tell which components are optimal, this depends on how correctly the layout is replicated. Seemingly miniscule differences can have an impact, especially on harmonics, so we recommend that you always verify this behaviour in your prototoypes, and update the matching if needed. We can assist with this if you need.

Best regards,

Andreas

RE: Antenna design check nRF52840 custom board

TSalty21 — Wed, 01 Jul 2020 15:54:05 GMT

Which matching component values would work better for this pcb,

the ones given in the base reference layouts or the ones used in development kit?

or is that impossible to tell in beforehand?

RE: Antenna design check nRF52840 custom board

TSalty21 — Wed, 01 Jul 2020 14:40:22 GMT

Yes, I'm still reorganising the vias. I should've payed more attention to their placement from the start.

Alright, I'll change the grounding of that pad.

Many thanks!

Tamás

RE: Antenna design check nRF52840 custom board

Andreas — Wed, 01 Jul 2020 14:19:30 GMT

Hi,

As you are using through vias for the GPIOs I would ideally want to see you try to fan the GPIOs out a little more before going through the via. This should hopefully not chop up the internal ground planes as much and provide the IC with a good ground connection.

You should also not ground the matching network capacitor closest to the ANT pin directly to the ground pour. Instead you should ground it into the center pad ground. Like in our reference layout:

Best regards,

Andreas