The board has a PCB antenna for the 2.5 GHz ISM Band, for stand alone operation on the Camp Area. For other frequencies an external antenna may be needed.

To improve radio reception a little bit you can just press a thumb against the upper right corner and be a human antenna. The most simple real external antenna is a single-wire copper cable (others may also work). This can be pressed against an edge of the little black resistor on the top right corner.

(then the 0 Ohm resistor will be sitting on the R314 pads; R314 and R315 share the upper left pad).

The SMA connector should be an edge-launch SMA connector for a PCB thickness of 1.6mm

Resistor turned 90 degrees

Alternative: Add bridge, remove resistor

Using a soldered copper cable as antenna:

Adding an SMA connector so that you can connect an external antenna for your specific needs.