A Goubau line or Sommerfeld–Goubau line, or G-line for short, is a single-wire transmission line used to conduct radio waves at UHF and microwave frequencies. The dielectric coated transmission line was invented by F. Harms in 1907 and George J. E. Goubau in 1950, based on work on surface waves on wires from 1899 by Arnold Sommerfeld. It is used as a feedline at UHF to link high frequency transmitters and receivers to their antennas, Coupling to and from the G-line is done with conical metal "launchers" or "catchers", with their narrow ends connected for example to the shield of coaxial feed line, and with the transmission line passing through a hole in the conical tips.
The Goubau line conducts energy via one-dimensional electromagnetic surface waves, analogous to the two-dimensional surface waves called ground waves that carry the signal from MF AM broadcasting stations to home AM radios. The ability of surface waves to bend and follow the contour of a conductor explains why AM radio stations can be received on the far side of hills, and how over-the-horizon radar works.
See also
- Surface wave
- Surface plasmon polariton
- Radio frequency power transmission
Patents
- , "Surface wave transmission line". George J. E. Goubau
- , "Launching and receiving of surface waves". George J. E. Goubau.