Coaxial Cable Types

In the coaxial cables, the electromagnetic field which carries signals exists between the inner and outer conductors owing to which you can lay these cables near metal objects without having to worry about power (signal) loss. At the same time, it also rules out the chances of any sort of external electromagnetic interference with the signal transmission. These and other such advantages of coaxial cables give them a definite edge over other types of radio transmission lines and add to their popularity.

Different Types of Coaxial Cables

Coaxial cable, also referred to as coax cable or simply coax, is a type of electrical cable wherein the inner copper conductor is surrounded by a tubular insulating layer - which, in turn, is surrounded by a tubular conducting shield. It is quite popular as a transmission line for high-frequency signals like the ones required for cable television transmission and computer networking. There exist different types of coax cables - all of which are designed to suit a specific purpose or requirement. Given below is a list of popular coaxial cables which are widely used in the field of radio frequency communications and networking today.

Hard Line Coaxial Cable: The hard line cable has a solid copper or copper plated aluminum conductor at the core and polyethylene foam along with pressurized gas or desiccated air as the dielectric in it. The shield is made from metals such as silver or gold (sometimes a combination of the two.) Even though hard line cable is used in various forms of radio communications, its use in broadcasting is by far the most popular.

Radiating Coax Cable: Even though the radiating coax is quite similar to hard line, it is constructed with slots which are tuned to specific RF wavelength of operation or radio frequency band which are cut into the shield. This tuning facilitates the necessary bi-directional leakage effect between the transmitter and the receiver.

RG-6 Coaxial Cable: This is undoubtedly the most common coaxial cable type and has several residential as well as commercial applications. It has a simple structure wherein the lone copper conductor at the core and outer protective covering are separated by a copper braided dielectric insulator. There exist different types of RG/6 coaxial cables - with the Plain RG/6 mostly used for internal and external wiring, while the waterproof Flooded coax is mostly used in underground wiring.

Twin-axial Cable: In case of twin-axial type coax, a pair of plastic-coated solid conducting wires form the core. These are surrounded by two copper or aluminum braids which are parted by some insulating material. The two plastic-coated solid conduction wires at the core of cable carry two differential electric voltages. This ensures that the maximum transmission and reception requirements are fulfilled, owing to which these cables are widely used in computer networking.

Triaxial Cable: In this type of coax, the single copper conductor at the core is surrounded by three protecting shields. Of these three shields, two are copper or aluminum layered meshes while the third is a dielectric insulator which lies between these two meshes. This structure of the triaxial cable makes it more efficient in terms of signal transmission and reduces signal leakage as well as external noise interference to a significant extent. The triaxial cable is mostly used in electronic applications wherein electromagnetic interference can play a spoilsport.

Semi-rigid Coaxial Cable: These are inflexible cables which have a solid conductor surrounding the insulator covered internal conductor. At higher frequencies - wherein skin effect tends to play a spoilsport, the solid covering turns out to be an advantage for this type of coax. It is most often used in applications wherein microwave signals have to be collected on some physical medium.

Since its invention way back in 1929, coax cable has come a long way to become an important component of different networks of communications today. Today, coax cables have become so popular that they boast of a major market share even when new alternatives in form of twisted pair copper wire and fiber optics are available in plenty.