A key to coaxial cable design is tight control of cable dimensions and materials. Together, they ensure that the of the cable takes on a fixed value. High-frequency signals are partially reflected at impedance mismatches, causing errors.
Simple coax cables carry only one connection. There are variations, such as , that place multiple connectors at the center and take advantage of transmission line properties to pass the signal. Applications sometimes bundle multiple separate coax cables inside a protective plastic outer layer applied to prevent mechanical damage.
Coaxial cable was invented and patented in 1880 by English engineer and mathematician Oliver Heaviside. AT&T established its first cross-continental coaxial transmission system in 1940.
Coaxial cable, also called coax, is used to transmit radio frequency (RF) signals. It has low emission losses and provides protection from electromagnetic interference, allowing signals with low power to be transmitted over longer distances. Coaxial cable is comprised of an inner core, insulator, shield, and outer cover. It is called coaxial because these sections all share the same axis. There are many different types of coaxial cable, each one with different physical and electronic properties designed for specific tasks. It is commonly used for carrying cable television signals along suburban streets and into homes.