An umbrella term, coaxial cable adapters are a type of small metal adapter. They generally serve to connect distinct pieces of coaxial cables together, or as an endpoint to attach a cable from a source to a receiver. In the electronics industry, coaxial cable adapters are sometimes considered a larger category, consisting of numerous parts including bushings, splitters, couplers, attenuators, male/female adapters, and terminating plugs.
Most commonly, the term coaxial cable adapters is interchangeable with RF connectors, and they are used in television and audio-visual capacities. They are employed as a hardpoint between coaxial cable originating from outside, and the cable that is connected directly to a TV, VCR, or other receiving unit. Operating in the megahertz range of the radio spectrum, coaxial cable adapters have a twofold purpose: transferring the signal carried by the coaxial cable to the receiving unit while mechanically maintaining a physical connection between the two. Physically, RF connectors consist of a fastening component, which can range from a threaded mechanism to a tab or quick-lock style mechanism, and springs which allow the coaxial source to contact the receiver's coaxial jack with a minimum of interference. They are typically coated with high-conductivity metals like silver or gold to optimize performance.
There are a number of standardized types of coaxial cable adapters. These include 7/16 DIN, Bayonet Neill-Concelman (BNC), the European standard IEC 169-2, and a wide variety of Ultra-High Frequency (UHF) connectors that are typically referred to by manufacturers' model names. There are also a host of miniature and smaller types of coaxial cable adapters available. Different applications demand different styles of adapter, and not only size but frequency range, impedance, and other specifications can have a profound impact on the quality and utility of a given adapter.
While HDMI technology and other advances mean that a coaxial source such as cable television or satellite is first routed through a receiver, coaxial cable adapters remain a critical component of the modern home entertainment equation. With advanced coaxial standards becoming more prevalent, the implementation of home networks over coaxial cables is increasingly common. Though coaxial cable is more expensive than equivalent lengths of Cat5 cabling, the ability of coax to handle both Ethernet and television programming have warranted its continued development, and updated standards of coaxial cable adapters are being developed to minimize interference. The standard providing for up to 1 Gigabit speed local area networking over coax is known as ITU-T G.hn.