coaxial

Coaxial, derived from the Latin axis meaning sharing a common axis, is a term used in various fields to indicate objects that are arranged along the same center line. In cable technology, a coaxial cable is a system in which a central conductor is surrounded by a dielectric insulator and a concentric conductive shield, all within an outer protective jacket. This arrangement preserves a consistent axis and helps contain and return signals along the same path.

Construction and properties are central to coaxial cables. The inner conductor is typically copper or aluminum, surrounded by a dielectric material that maintains spacing between the conductor and the shield. The outer conductor acts as a shield and a return path, often implemented as braided shielding, foil, or a combination. The combination is designed to provide a characteristic impedance, commonly 50 ohms or 75 ohms, which minimizes signal reflections. The outer jacket protects the assembly from environmental damage and mechanical wear. Shielding guards against electromagnetic interference and reduces signal leakage.

Uses and variants are widespread. Coaxial cables are a standard medium for radio frequency transmission, television distribution, and many data networks, valued for their shielding, durability, and flexibility. They use a range of connectors such as BNC, SMA, and F-type to create reliable interfaces with equipment. Variants differ in impedance, loss characteristics, and shielding quality, reflecting the intended frequency range and installation environment.

In addition to engineering, the term coaxial appears in geometry, where it describes objects that share a common axis or, in circle geometry, a family of circles sharing a common radical axis. This reflects the broader concept of alignment along a single central line.