Antenna tuning connector

[sakitten123]

On the nRF51 DK there is a MM8130-2600 connector. I suppose it is used for connecting coax cable when tuning the antenna(?)

The connector is quite expensive, though. Is it possible to include the connector on prototypes, and when the antenna length and shunt capacitor value has been found (used the connector to be able to do measurements), remove the connector component from the production schematic & pcb?

Why have you kept the connector on production DKs?

Is there any other way to connect the antenna tuning measurement equipment? Simply a via hole? I don't know what the measurement equipment/cables looks like, so I'm having trouble picturing what is needed. Should the connection be made before or after the shunt capacitor?

[AmbystomaLabs]

The connector is just a 50ohm test connection. It is not used for tuning.

Depending on the development work required, an engineer may do either radiated or conducted testing and this is a convenient way to bypass the antenna.

In production the same style connector may be used as a convenient way to measure conducted power output and calibrate the unit to the correct power output. Or, to measure radio performance for quality assurance. Though, since what goes out the antenna is the most important thing you should make sure your QA includes a radiated test.

Depending on the certification standards your product has to comply with you may or may not need a 50ohm port on your product. Most BLE devices are certified without a 50ohm port and without any factory power calibration making such a connector unnecessary.

[FormerMember]

FCC and ETSI qualification (and most other regulatory standards) can be done by tested using radiated measurements only. And in that case, a connector is not necessary. It is however possible to do some of the testing conducted.

Note: For Korea-qualification, the RX LO measurements should be done conducted.