Coaxial cable

Coaxial cable refers to a cable designed to carry a high frequency or broadband signal (as opposed to carrying power) and to protect that signal from outside interference.

The cable is constructed with an inner conductor that carries the signal. This is surrounded with a cylindrical layer of insulation. Around, and completely enclosing, the layer of insulation is a second conductor which is normally connected to ground. Because the outer conductor completely encloses the inner, it forms a Faraday cage and prevents external interference from reaching the signal carrying conductor. Similarly, the signal is prevented from being radiated from the central conductor.

Coaxial cables are usually terminated with RF connectors.