User Manual

nRF51 Development Kit User Guide v1.0
Page 19
5.8 RF measurements
The nRF51 DK board is equipped with a small size coaxial connector for conducted measurements of the RF
signal (J1). The connector is of SWF type from Murata (part no. MM8130-2600) with an internal switch. By
default, when there is no cable attached, the RF signal is routed to the on-board PCB trace antenna.
A test probe is available from Murata, part no. MXHS83QE3000, which has a standard SMA connection on
the other end for connecting instruments. When connecting the test probe, the internal switch in the SWF
connector will disconnect the PCB antenna and connect the RF signal from the nRF51 device to the test
probe.
Figure 18 Connecting a spectrum analyzer
The connector and test probe will add loss to the RF signal which should be taken into account when doing
measurements, see Table 4.
Table 4 Typically loss in connector and test probe
Frequency (MHz) Loss (dB)
2440 1.0
4880 1.7
7320 2.6
J1