"AT&T is proud to follow in the footsteps of Espenschied and Affel as we continue to drive innovation."
Dave Belanger, chief scientist at AT&T Labs
In the early 1920s it was clear to communications engineers that high-frequency transmission lines were paramountto the success of any further developments in communications, since ordinary wires and cables simply could not cope. Two engineers at Bell Laboratories, Lloyd Espenschied (1889-1986) and Herman A. Affel (1893-1972), came to the rescue. Together they created the coaxial cable, which is capable of carrying high-frequency (or broadband) signals successfully. Instead of having just single strands of copper covered by a jacket of a flexible plastic, they widened their working diameter to include an insulating spacer and a conducting shield, which gives the cable a very distinctive cross section.
Running through the very center of the cable is the conductor, which carries the signal. Wrapped around this is the inner dielectric insulator and wrapped around that is a conducting shield that reduces electromagnetic interference from any external sources, meaning that the signal stays clear. The shield can be made from layers of braided wire (which allows flexibility, but creates gaps) or can be a solid metal tube (which is rigid, but more secure). Usually, the whole cable is coated in some sort of vinyl material.
The name coaxial means "sharing the same axis," which is what the conductor, the spacer, the shield, and the jacket all do.
