Coaxial Cable

Coaxial  cable  carries signals  of higher  frequency ranges than those in twisted pair cable. In part  because the two media are constructed quite  differently. Instead of having two  in wires. Coaxial  cable  has a central core conductor of solid or standard wire ( usually copper)  enclosed in an insulating sheath which  is in turn encased in an outer conductor  of metal  foil braid or a combination of the two. The outer metallic  wrapping servers both as a shield against noise and as  the second conductor  which completes the circuit. The  outer conductor is also enclosed in an insulating sheath and the whole  cable is protected by a  plastic cover  with this  construction and a special  insulation and shielding coaxial  cable can have high  bit rate.

        figure Coaxial Cable

In past coaxial cable was  widely  used in  analog  telephone  networks  where a single  coaxial  network  could  carry 10,000 voice  signals. Latte it was used in digital telephone networks.  Where  a single  coaxial  cable  could carry digital data up to 600Mbps. However coaxial  cable in telephone  networks  has largely been replaced today  with fiber optic cable.

Coaxial cables  are categorized  by their  radio government (RG) rating. Each  cable  defined  by RG rating  is adapted for  a specialized functions  as shown  in table below.