coaxiaal

Coaxiaal, or coaxial in English, refers to a geometry in which conductors share a common axis. In transmission-line use, a typical coaxial arrangement consists of a central conductor surrounded by an insulating dielectric, which is enclosed by a second conductor that acts as a shield and shares the same axis. The outer surface is protected by an outer jacket. The arrangement confines electromagnetic fields to the space between conductors, providing effective shielding from external interference.

The characteristic impedance of a coaxial line is determined by its dimensions and the dielectric material; common values are 50 ohms and 75 ohms. Coaxial cables support relatively low-loss transmission at radio frequencies and can carry signals over moderate to long distances with good shielding. They are used for RF links, cable television, satellite downlinks, and as feeds for antennas. Rigid coaxial cables are used in test equipment, while flexible varieties (for example, small-diameter types) are common in consumer electronics and installations.

Typical components include the central conductor (often copper or copper-clad steel), a dielectric such as PTFE or polyethylene, an outer conductor made of braided copper or foil, and an outer jacket. Connectors—such as BNC, SMA, N-type, and F-type—are designed to preserve the impedance and shielding of the line.

Coaxial systems are chosen for their shielding, stable impedance, and robustness in field conditions, though they can be relatively bulky and less flexible than alternative media, and may incur more loss at very high frequencies or long distances.