nRF52832 - Initial values for capacitors for NFC coil

[Abomin3v3l]

Hi all.

I did a layout with NFC antenna with a nRF52832 chip.

In the schematic (suggesten on datasheet) I have antenna coil with 2 capacitors to ground.

Drawing of NFC coil on layout:

There is two round holes at the start and end of the coil, the total lenght of coil is 455mm. It follows this design of ST's online tool eDesignSuite.

It is to have 1.08uH and 1.56 ohms.

Resistance was calculated with an  online tool.

Considering these informations, what values of capacitors (C16 and C17) I could use as a starting point for my PCB prototype?

Regards,

Jeferson.

[Kaja]

Hi Jeferson,

you can estimate the values or you can tune the antenna, see our white paper. 

We can help you with antenna tuning, you should remove the ground arm under the antenna. 

Best regards,
Kaja

[Abomin3v3l]

Hi Kaja.
Could you please check if my calculations are correct?
Regards.