Introduction to Coaxial Cables

A coaxial cable is a type of wire and signal transmission line, usually made of four layers of material: the innermost layer is a conductive copper wire, the outer layer of the wire is surrounded by a layer of plastic (used as an insulator or dielectric), and the outer layer of the insulation is also a thin mesh of conductive material (usually copper or alloy), and the outer layer of the conductive material is used as the outer skin.

Coaxial cables can be used for the transmission of analog and digital signals, and are suitable for various applications, including the most important ones such as cable television transmission, long-distance telephone transmission, short distance connections between computer systems, and local area networks. Coaxial cable, as a means of transmitting television signals to thousands of households, has developed rapidly, which is cable television. A cable television system can load dozens or even hundreds of television channels, and its transmission range can reach tens of kilometers. Coaxial cables have long been an important component of long-distance telephone networks. Today, it faces increasingly fierce competition from fiber optics, ground microwaves, and satellites.

Coaxial cable is a type of cable that consists of a concentric conductor surrounded by a conductive shield and separated by two dielectric materials (insulation materials); Many coaxial cables also have protective jackets or sheaths. The term 'coaxial' refers to internal conductors and external shielding that share a geometric axis.

form

A coaxial cable consists of three parts: a central conductor, a dielectric material layer, and a shielding layer. The central conductor is located in the middle of the coaxial cable, which can be solid or twisted. Surrounding the central conductor is the dielectric layer, which plays a role in buffering and fixing the central conductor. Outside the dielectric layer is the shielding layer of coaxial cables, usually copper foil, aluminum foil, woven mesh, or a combination of the above. Then use things like polyvinyl chloride (PVC) to isolate the shielding layer from the environment.

model

RG-8, RG-9, and RG-11 all have an impedance of 50 Ω, used for thick cable Ethernet

RG-58, impedance 50 Ω, used for thin cable Ethernet

RG-59 and RG-75 have impedances of 75 Ω, used in television systems

RG-62, impedance 93 Ω, used for ARCnet networks and IBM 3270 networks