1884- Werner von Siemens obtained the coaxial cable patent in Germany.
194 1 year ── in the United States, at & amp； T laid the first commercial coaxial cable. From Minneapolis, Minnesota to Steven Puying, Wisconsin. The L 1 system it uses can accommodate a TV band or 480 telephone lines.
1956 ── TAT- 1, the world's first transatlantic coaxial cable, has been laid. (Coaxial cable) A cable consisting of coaxial conductors insulated from each other inside and outside: the inner conductor is copper wire and the outer conductor is copper tube or mesh. The electromagnetic field is enclosed between the inner and outer conductors, so the radiation loss is small and it is less affected by external interference. It is usually used to transmit multiple telephones and televisions.
The name of coaxial cable is related to its structure. Coaxial cable is also one of the most common transmission media in LAN. The conductor pair used to transmit information is selected according to the structure that the inner conductor (thin core) is sheathed with a cylindrical outer conductor and the two conductors are isolated from each other by insulating materials. The center of the outer conductor and the core line of the central shaft are on the same axis, so it is called coaxial cable. The coaxial cable is designed in this way to prevent external electromagnetic waves from interfering with the transmission of abnormal signals.