We explain what a coaxial cable is, its component parts and its common applications. Also, its advantages and disadvantages.
What is a coaxial cable?
Coaxial or coaxial cable is a type of cable commonly used in the transmission of electrical signals to networks communications or computer networks.
Its name comes from the fact that it consists of two materials drivers arranged concentrically along the same axis: the central one is covered by an insulator which in turn is covered by the other conductor, thus building an electrically shielded transmission circuit.
Coaxial cable was created in the 1930s, and it quickly replaced twisted-pair cable, since it allowed faster and safer transmission of information. Today it is being replaced by the optical fiber, more compatible with the contemporary needs of high frequencies and digitization of transmissions.
Uses and applications
Coaxial cable is an excellent choice when you need to send information or current over long distances safely.
Before being displaced by fiberglass, it was used extensively for these purposes, underground and even under the Water, especially for analog telephony and certain digital transmission systems.
Today it is common to find a coaxial cable connecting:
- The satellite antenna and decoder TV by subscription;
- Short wave radio transmitters and their broadcasting antenna;
- On the video signal distribution lines;
- In submarine cables and long distance telephone networks.
Coaxial cable parts
A coaxial cable is made up of the following parts:
- Core. Located in the center of the cable, it consists of a single cable called “solid”, although eventually it can be several wires in one. It is the main route of electrical and electronic information that the cable allows.
- Dielectric. Around the core is an insulating layer known as a dielectric, whose function is to keep two components separate whose contact would produce a short circuit, such as the core and the mesh.
- Braided wire mesh. Covering the dielectric is a braided metal mesh, which serves as a screen to protect the core from radiation and interference, and therefore guarantees the fidelity of the transmission. It is possible that in some cases, apart from this braided mesh, there is a metallic foil covering the dielectric (double shielding).
- External cover. It is the "skin" of the cable, which surrounds and covers it, and is usually made of Teflon, rubber or plastic (PVC), thus serving as a protector and insulator. It is usually painted color black, too.
Advantages and disadvantages
Compared to previous cable models, coaxial represented a huge leap forward. On the one hand, it is flexible but at the same time resistant to attenuation and interference, since the screen of twisted wires absorbs the lost signals and isolates the information transmitted within the cable.
In addition, it supports large amounts of data in a rather simple physical system to manufacture.
However, given the contemporary transmission needs, typical of the digital age, coaxial cable reveals its limitations: it transmits simple signals, without frequency modulation, and incidentally requires special terminals for the physical connection.
For that reason, today it is preferred to use fiberglass, with which, in addition, there is no risks short circuit when by damaged cables.