Waveguide

In telecommunication, a waveguide is a material medium that confines and guides a propagating electromagnetic wave.

In the microwave regime, a waveguide normally consists of a hollow metallic conductor, usually rectangular, elliptical, or circular in cross section. This type of waveguide may, under certain conditions, contain a solid or gaseous dielectric material.

In the optical regime, a waveguide used as a long transmission line consists of a solid dielectric filament (optical fiber), usually circular in cross section. In integrated optical circuits an optical waveguide may consist of a thin dielectric film.

In the radio frequency regime, ionized layers of the stratosphere and refractive surfaces of the troposphere may also act as a waveguide.

Source: from Federal Standard 1037C and from MIL-STD-188

In digital computing, the term Waveguide can also be used for data buffers used as delay lines that simulate physical Waveguide behavior, such as in Digital Waveguide Synthesis.

Waveguide propagation modes depend on the operating wavelength and polarization and the shape and size of the guide. In hollow metallic waveguides, the fundamental modes are the transverse electric TE_1,0 mode for rectangular and TE_1,1 for circular waveguides, seen here in cross-section:

Waveguide

See also