RF Conducted Emissions measurements with nRF52832

RE: RF Conducted Emissions measurements with nRF52832

eiadj — Thu, 19 Jul 2018 18:29:13 GMT

Excellent, this was very helpful - Thanks!

RE: RF Conducted Emissions measurements with nRF52832

Andreas — Wed, 18 Jul 2018 07:13:19 GMT

Hi,

C7 in your design should be desoldered and L3+C8 should be left in place. Alternatively, the trace between C7 and L3 can be cut. The coaxial cable should then be soldered on the end of the trace left, on the C7 side. We frequently use Huber+Suhner EZ-47 semi rigid cables with Huber+Suhner 21_SMA-50-1-2/111_NE SMA connectors.

The ant pin impedance is not relevant for this, the measurement should be performed in the 50 ohm reference point which is between L3 and C7.

Best regards,

Andreas

RE: RF Conducted Emissions measurements with nRF52832

eiadj — Wed, 18 Jul 2018 02:10:00 GMT

Note: the assumption we're making here is that the impedance of the connection to board will also be 50 ohms. For that reason it would be useful to know the impedance of the ANT pin on the Nordic - is this information available? The data sheet says the reference circuit (with matching network) are designed for 50 ohm antennas but the impedance of the pin isn't provided.