Coaxial cable is a cable used in the transmission of data. As a transmission line, a coaxial cable carries high-frequency data/radio frequency signals. It has high bandwidths and greater transmission capacity to ensure it provides service without any great interruptions. Most commonly it is used to connect televisions to a cable TV service.
It was invented by English engineer and mathematician Oliver Heaviside in the year 1880 and he had his invention patented the same year. One of the main advantages of coaxial cable is that the electromagnetic field exists only between inner and outer conductors. Thus, making it safe to be installed alongside other metals without any power loss. 60 years after this invention, AT&T Telecommunication services established the first-ever cross-continental coaxial transmission system in 1940.
The coaxial cable is made out of 4 components and is constructed as follows:
1. Inner Conductor/Core Wire – the core or the inner conductor wire serves as a primary physical channel through which data and signal are transmitted. It is the first of the materials to be used in the making of a coaxial cable. In the cable TV Industry, this core wire is copper plated. For higher frequency, the silver-coated wire can be used.
2. Dielectric insulator – the core wire is then surrounded by another insulation of plastic. It is the best option we have for a dielectric insulator as it provides a good dielectric strength, as durable as it is, and excellent fire resistance. Foam can also be used as dielectric insulation which allows more space for core wire and more space for air and gas needed to reduce loss in frequency and signals but the foam dielectric insulator can also absorb moisture which may increase the loss. With two more protective shields upon it, electric and magnetic fields are restricted in this dielectric insulator. That is how coaxial cable becomes a leakage-proof solution, safe to be installed with other metals.
3. Braided Copper – Braided Copper is used as a sheath beneath the uppermost layer. It ensures a hassle-free transmission of the data because of its’ protective components which prevent electromagnetic interference even if the signal is weak.
4. Insulating layer or upper layer – Most commonly PVC is used as the insulating layer to cover the other components inside but fire resistance is needed and for that, plastic and Teflon is also an alternative for the protection.