4. Glossary – Definitions

Linear phase shift; longitudinal wave number

In uniform waveguides (longitudinally invariant cross-section), the modes have constant-phase wavefronts moving at phase velocity. The change in phase of these fronts per unit length is given by the linear phase shift associated with each mode. It also gives the guided wavelength, equal to a phase shift of 2π in the longitudinal direction.

Diagramme de dispersion; dispersion diagram

It is the fundamental figure of a guide. It represents the curve relating angular frequency ω to linear phase shift β for each mode. The main information about a mode can be derived from it: cutoff frequency, phase and group velocity, single-mode band.

Dispersion; dispersion

Phenomenon that occurs for any mode that is not a pure TEM mode. It...