The arrangement 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
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.
Hardline Coaxial Cable
Hardline coax 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 like silver or gold, or at times, a combination of the two. Even though hardline 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 similar to hardline, 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 facilitates the necessary bi-directional leakage effect between the transmitter and receiver.
RG/6 Coaxial Cable
This is undoubtedly the most common coaxial cable 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, and the waterproof Flooded coax mostly used in underground wiring.
In the twin-axial type coax, the core is formed by a pair of plastic-coated solid conducting wires. These are surrounded by two copper or aluminum braids which are parted by some insulating material.
The two wires at the core carry two differential electric voltages, thus ensuring that the maximum transmission and reception requirements are fulfilled. Owing to this, these cables are widely used in computer networking.
In this type of coax, the single copper conductor at the core is surrounded by three protecting 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. The triaxial cable is mostly used in electronic applications wherein electromagnetic interference can play a spoilsport.
Semi-rigid Coaxial Cable
A type of inflexible cable, the semi-rigid coaxial has 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. It is most often used in applications wherein microwave signals have to be collected on some physical medium.
Since their invention back in 1929, these cables have come a long way to become an important component of different networks of communications. Today, coax cables have become so popular that they boast of a major market share even when new alternatives, like twisted pair copper wire and fiber optics, are available in plenty.