nrf52832 Antenna Matching

[TTV1-BGS9]

Good Afternoon,

I'm designing a 4-layer PCB based on an NRF52832 (QFAA) paired wit h a Molex 479480001 SMT Antenna, and I was hoping for some feedback on Antenna Matching.

Here's a partial screenshot of the current layout, followed by the associated schematic:

As per the application notes of the nrf52832 (QFAA footprint), I've including an 0.8pF Capacitor (C10) and 3.9nH Inductor (L3) for matching at the output of the IC. There's what I hope is a reasonable approximation of a coplanar waveguide on the PCB, with trace width adjusted to match my layer stack-up and PCB fab specs.

As per the Application Note of the Molex antenna, I've added a 0R jumper (R14), 4.3nH inductor (L4) and optional capacitor (C9) close to the antenna:

Are there any glaring mistakes here, or anything I can do to further improve the design in terms of RF performance, prior to sending the PCB out for fabrication?

Thank you very much!

[JONATHAN LL]

Hi,

We have some extra info here: 
https://devzone.nordicsemi.com/guides/hardware-design-test-and-measuring/b/nrf5x/posts/general-pcb-design-guidelines-for-nrf52-series 

But mostly ok, just follow the layout recommendation for best results. 

C8 should only be connected to pin and inner GND center pad, so you can disconnect it from the top GND layer(black X), reason for this is due to filtering of harmonics. 

Like this:



Regards,
Jonathan