An antenna is a device that propagates radio frequency (RF) signals through the air. The transmitter (the Wi-Fi card or access point) sends an RF signal to the antenna, which amplifies the signal and sends it along through the medium of air.
When you are thinking about antennas, you need to think about the following characteristics:
Antennas used with Wi-Fi need to be tuned to 2.4GHz (802.11b or 802.11g) or 5GHz (802.11a). The frequency of the antenna needs to match the frequency of the radio transmitter.
Antennas are rated to handle a specific amount of power put out by a radio transmitter. In the case of Wi-Fi, this is not a great issue because most antennas are capable of handling ...