Antenna - Buffalo AirStation WHR-G54S User Manual

Antenna

The WHR-G54S's external antenna will usually give the best
performance if oriented to point straight up. If your AirStation is
resting on its side, use the antenna's swivel and twist function to
orient it pointed upward.
In some environments it's desirable to further increase range by
installing an external, higher-gain antenna. External antennas come
in all shapes and sizes. Antennas also come with different connectors.
The WHR-G54S has an RP-SMA connector on it. If your antenna has
a different kind of connector, you'll need an adaptor.
To install a different antenna, unscrew the stock antenna from
the RP-SMA connector on top of the AirStation, and screw on the
connector or adaptor from your new antenna.