How Does Coaxial Cable Work?

Coaxial cable is an electrical cable with two concentric conductors, and the conductor and the shield share the same axis. The most common coaxial cable consists of a copper wire conductor surrounded by an dielectric or insulation layer. On the outside of insulation is the layer of shielding which is made up of braided mesh and aluminum foil. The entire cable is surrounded by a PVC jacket. 

Coaxial cables have an external conductive shield layer. Other material layers can be used on the outside of the coaxial cable to improve environmental performance, EM shielding capability and flexibility. Coaxial cables can be made from braided conductor strands with layering, which makes the cable highly flexible, reconfigurable, lightweight and durable. As long as the cylindrical conductors of the coaxial cable remain concentric, bending and flexing could hardly have impact on the performance of the cable. Therefore, coaxial cables are typically connected to coaxial connectors by a screw-type mechanism, and a torque wrench is used for ensuring the tightness.

What Are Coaxial Cables Used For?

Coaxial cable can be used for the transmission of analog and digital signals, and is suitable for a variety of applications, such as television broadcasting, long-distance telephone transmission, short-distance connections between computer systems, and local area networks. Coaxial cable has developed rapidly as a means of spreading television signals to thousands of households, which is cable television. A cable TV system can load dozens or even hundreds of TV channels, and its transmission range can reach tens of kilometers. Besides, coaxial cables have long been an important part of long-distance telephone networks.

Working Principle

Coaxial cable is divided into four layers from the inside to the outside: the central copper wire (single-strand solid wire or stranded wire), foaming insulation, mesh conductive layer and wire sheath. The central copper wire and the mesh-like conductive layer form a current loop.

Coaxial cables conduct alternating current rather than direct current, which means that the direction of the current is reversed several times per second. If a normal cable is used to transmit high-frequency currents, the wire acts as an antenna that emits radio outward. This effect loses the power of the signal and reduces the received signal strength. Thus, coaxial cables are designed to solve this problem. The radio emitted by the central wire is isolated by the mesh conductive layer, which can control the emitted radio by grounding.

There is also a problem with coaxial cables. If a certain section of the cable is squeezed or twisted, the distance between the center wire and the mesh conductive layer is not always consistent, which will cause internal radio waves reflected back to the source of the signal. This effect reduces the acceptable signal power. To overcome this problem, a layer of plastic insulation is added between the center wire and the mesh conductive layer to ensure a consistent distance between them. This also makes the cable relatively straight and not easy to bend.

To Buy Best Coaxial Cables

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