Goubau line

As Goubau line, also Goubot - line or G- line, refers to a single-wire waveguide for technically -used frequencies. This cable is low loss, but it is rarely used, eg, for coverage of remote reception areas with FM radio and television. The line is named after Georg Goubau, which she developed in 1950.

It is an overhead line, needed to metallic a large distance and (especially lossy ) dielectric parts and must not be laid bent to keep the radiation low as possible.

Basic structure

A coaxial cable is reduced to the inner conductor. The wire is surrounded by a dielectric layer, which reduces the propagation velocity of the wave in the immediate vicinity of the conductor. This creates an easy to head out directed Poynting vector that guides the shaft against a non-insulated single-wire waveguide close along the conductor. The reduction of the losses with respect to the coaxial cable arises because most of the electric field of the wave is beyond the lossy dielectric.

For input and complete the line Exponentialtrichter be used, which make the gradual transition of the characteristic impedance of the coaxial cable in those of the single-wire line. The hopper can also be produced in a material-saving skeleton construction. The distance between the individual segments must be less than but a half wavelength. The expansion of the hopper must be greater than half the wavelength.

Because of these requirements, the configuration is only suitable for higher frequencies from about 50 MHz upwards. For short or medium wave is then due to the unrealistic dimensions of the hopper and the necessary height above ground, the construction is not suitable, but conceivable.

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