Coaxiaux

Coaxiaux is a term used to describe coaxial systems, particularly coaxial cables, and is common in French-language technical writing. In English, coaxial or coaxial cables are named for their design that places two conductors on a common axis.

A typical coaxial cable consists of a central conductor surrounded by a dielectric insulator, an outer conductor that serves as a shield, and an outer protective jacket. The dielectric keeps the electric field contained between the inner and outer conductors, reducing leakage and interference. The outer shield also protects the signal from external electromagnetic noise. The geometry and materials determine the cable’s characteristic impedance, commonly 50 ohms or 75 ohms, and influence losses and bandwidth.

Electrical performance depends on frequency, conductor resistance, dielectric losses, and shielding quality. Attenuation increases with frequency and with longer runs, and skin effect raises the effective resistance of the conductors at higher frequencies. Strong shielding and high-quality terminations are essential to minimize reflections and maintain signal integrity.

Variants and construction include rigid coaxial cables for microwave applications, semi-rigid and flexible types for general use, and foamed or solid dielectrics (such as PTFE or polyethylene) to balance weight, flexibility, and loss. Connectors—such as BNC, N-type, SMA, and F-type—enable modular terminations, while proper impedance matching is crucial to avoid standing waves.

Applications span RF and microwave transmission, cable television distribution, and certain data networks. While many networks have shifted toward twisted-pair or fiber, coaxiaux remain widely used for high-frequency links, home video distribution, and long-run RF communications due to their shielding and predictable impedance.