A
shielded cable is an electrical
cable of one or more
insulated conductors enclosed by a common conductive layer. The shield may be composed of
braided strands of
copper (or other metal, such as aluminium), a non-braided spiral winding of copper tape, or a layer of
conducting polymer. Usually this shield is covered with a jacket. The shield acts as a
Faraday cage to reduce electrical noise from affecting the signals, and to reduce
electromagnetic radiation that may interfere with other devices. (For more, see
electromagnetic interference). The shield minimizes
capacitively coupled noise from other electrical sources. The shield must be applied across cable splices.