The D-Link DWL-50AT is a 5dBi Gain Dipole Antenna with Reverse SMA
It can help to improve the transmit rate and extend the transmit distance of
any Air, AirPlus, AirPlusG+, AirPlusG or AirXtremeG Access Point or wireless
gateway router (e.g. DI-714P+) which have a reverse SMA connector.
To ensure a better performance, you should not only improve the RF on
transmitter but also that on the receiver, as well.