Propagation constant a conductor. The skin effect causes R along the conductor to be approximately dependent on frequency according to Losses in the dielectric depend on the loss tangent (tan "δ") of the material divided by the wavelength of the signal. Thus they are directly proportional to the frequency. The attenuation constant for a particular propagation mode in an optical fiber is the real part of the axial propagation constant. In electromagnetic theory, the phase constant, also called phase change constant, parameter or coefficient is the imaginary component of the propagation constant for a plane wave. It represents the change in phase
Standing wave line patterns are called Chladni figures. In three-dimensional resonators, such as musical instrument sound boxes and microwave cavity resonators, there are nodal surfaces. Standing wave ratio (SWR) is the ratio of the amplitude at the antinode (maximum) to the amplitude at the node (minimum). A pure standing wave will have an infinite SWR. It will also have a constant phase at any point in space (but it may undergo a 180° inversion every half cycle). A finite, non-zero SWR indicates a wave that is partially stationary and partially travelling. Such waves can be decomposed into two linearly superpositional components (assuming