The 2.4 GHz signals can be propagated through the coaxial connectors J1 and J2. The connectors allow you to perform conducted measurements or to attach external antennas.
When an adapter cable is not connected, the RF signal is routed to the onboard antenna. When an adapter cable is connected, the internal switch in the Microwave coaxial connector with switch (SWF) connector disconnects the onboard antenna and connects the RF signal from the nRF5340 System on Chip (SoC) or nR21540 RF FEM to the adapter.
You can use a Murata adapter cable (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.