136 years ago today, on April 6 1880, Oliver Heaviside was granted British Patent 1407 for the coaxial cable.
Heaviside was 30 years old and had left formal education at the age of 16. He taught himself physics, mathematics, and electrical engineering while working as a telegraph operator. Researching at home, he began to publish his findings on attenuation and inductance in telegraph lines.
Existing cabling had significant problems with interference:
When a number of wires run parallel to one another, either suspended or otherwise, any change in the current flowing in one wire causes currents in all the rest by induction, and the effect may be so great as to seriously interfere with the working of telephonic circuits, and to a less degree of ordinary telegraphic circuits also.
Heaviside’s solution was the coaxial cable, an inner conductor surrounded by an insulating layer, which was then surrounded by a conducting shield.
My improvements have for object to obtain perfect protection, and to render a circuit completely independent under all circumstances of external inductive influences. For this purpose I use two insulated conductors for the circuit, and place one of them inside the other; thus, one conductor may be a wire, and the other a tube or sheath, which must also be insulated. When the tube and inner wire are electrically connected at both ends of the line, as through apparatus in the usual manner, the circuit as thus described is completely independent of other circuits, and any number of such circuits, each containing an insulated tube and inner wire, may be laid side by side without any mutual inductive interference, and without interference from other wires worked in ordinary manners.
Today we use coaxial cable in all our cellular repeater kits to connect indoor and outdoor antennas to amplifier units. Various types of coaxial cable are available depending on the length of cable required and the strength of the signal booster kit. Outside the world of repeaters, coaxial cable is used to connect radio and video, in cable television connections and satellite dishes. It was used for Ethernet computer networks, and for telephone, radio and television networks, but this has now been superseded by fiber optic and satellite options.
Oliver Heaviside continued to research and publish in the field of electrical engineering, and over the following decades he coined the terms for conductance, impedance, and inductance, among others, and developed important methods of vector analysis. He was made a Fellow of the Royal Society in 1891, and was the first recipient of the Faraday medal in 1922.