RE: How to design the RF of NRF52810

Jørn — Mon, 21 Aug 2017 11:51:47 GMT

Hello

The RF portion is very sensitive to changes, which is why it is recommended you follow the reference schematic and layout closely as it is designed to conform with FCC and ETSI guidelines. When following the layout it is important you try and copy it as close as possible, as trace widths, distance to ground plane, changes in trace length, component sizes and antenna geometry can greatly affect the result. For design guidelines see this blogpost.

Nordics reference design for the nRF52 series uses an inductor (L1) and a capacitor (C3) to match the chip to 50 Ohm and handle harmonics. If you are using a simple PCB monopole antenna, as is present on the 52 development kit you only need a shunt capacitor, in combination with trimming the antenna length, to match the antenna to 50 Ohm.

Unfortunately, we do not have any guidelines for designing an IFA. The antenna will need to be matched as close to 50 Ohm as possible over the frequency band. You should also ensure that harmonics are within the regulatory demands. For more information on regulatory and compliance standards see this whitepaper.

Best regards

Jørn Frøysa