What is a coaxial cable used for?

Coaxial cable is a type of cable that has an inner conductor surrounded by an insulating layer, surrounded by conductive shielding (outer conductor), and a protective outer jacket. The diagram below illustrates the construction of a typical cable. Electrical signal flows on the center conductor.

1. Center conductor - copper-clad steel.

2. Center conductor bond - clean stripping polymer is utilized to block moisture migration.

3. Dielectric - polyethylene, closed-cell foam with high VP providing mechanical stability.

4. First outer conductor - an aluminum-polymer-aluminum tape securely bonded to the dielectric.

5. Second outer conductor - a 34 or 36 AWG aluminum braid

6. Third outer conductor - an additional aluminum-polymer-aluminum tape is used in tri-shield and quad-shield constructions to further enhance HF shield isolation before and after flexure.

7. Fourth outer conductor (optional) - an additional 34 or 36 AWG aluminum braid is used in quad-shield constructions to further improve LF shield isolation in extreme RF noise environments.

8. Corrosion resistant protectant

Indoor and aerial - a non-drip material designed to prevent corrosion of metallic components of the cable.

Underground - a flowing compound able to prevent moisture migration.

9. Jacket - a UV stable outer jacket of either polyethylene (PE) or flame retardant polyvinyl chloride (PVC) to protect the core during the life of the cable.

10. Integral messenger - a galvanized, carbon steel wire support member attached to the cable by a separable web.

Uses of coaxial cables

In the home and small offices, short coaxial cables are used for cable television, home video equipment, amateur radio equipment and measuring devices. Historically, coaxial cables were also used as an early form of Ethernet, supporting speeds of up to 10 Mbps, but coax has supplanted by the use of twisted pair cabling. However, they remain widely in use for cable broadband internet. Coaxial cables are also used in automobiles, aircraft, military and medical equipment, as well as to connect satellite dishes, radio and television antennae to their respective receivers.