The LTE signals are propagated through a coaxial connector. This makes it possible to perform conducted measurements or attach external antennas.
By default, when no cable is attached, the RF signal is routed to the onboard antenna. When connecting the adapter, the internal switch in the SWF connector will disconnect the onboard antenna and connect the RF signal from the nRF9160 to the adapter.
The connector is of SWF type (Murata part no. MM8130-2600) with an internal switch. An adapter is available (Murata part no. MXHS83QE3000) with a standard SMA connection on the other end for connecting instruments. The adapter is not included in the kit. The insertion loss in the adapter cable is approximately 0.5–1 dB.
Figure 1. Connecting a spectrum analyzer
