coaxial cable - technical definition

A very robust shielded copper cable. All components are symmetrically arranged around a common axis, or center point, hence the term coaxial. A coax cable has a relatively thick center conductor (in comparison to a twisted-pair conductor), generally solid, although stranded wire sometimes is used in applications requiring greater flex strength.The metal used for the inner conductor may be bare copper, silvered copper, tinned copper, copper-clad aluminum or copper-covered steel. A layer of dielectric material, either foam or solid, generally surrounds the inner conductor, serving to separate it from the single outer conductor, or sometimes two outer conductors.The conductor(s) comprising the outer shield generally consists of a solid aluminum foil, although a braided or stranded metal screen of aluminum, bare copper, silvered copper, copper-clad aluminum, or tinned copper may be used. The entire cable is then protected by a sheath of dielectric material such as PVC or Teflon