Cable

Coaxial cable is normally used to connect a radio transceiver to an antenna. Each coaxial cable is designed for specific impedance. In WiFi equipment as well as most radios, we normally used 50-ohm impedance coaxial cable. Fail to meet the impedance will reflect the radio signal from the transmitter back into the transmitter rather than to the antenna. Thus, the impedance of the transmitter, the coaxial cable and the antenna must match to 50 ohm.

Unfortunately, the use of coaxial cable introduces signal loss before it reaches the antenna or vice versa the receiver. Shown in the table is the cable loss at 2.4 GHz for several type of coaxial cable.