Effect of a magnetic wall and a conducting plane on the characteristics of magnetostatic waves in an in-plane-magnetized ferrite plate

The dispersion relations for an in-plane-magnetized ferrite plate with an arbitrary combination of magnetic-wall or perfectly conducting plane boundary conditions imposed at a distance from the plate’s surfaces are compared. A rule is formulated so that a dispersion relation for one of the structures can be used to derive the equation for any other structure. The isofrequency and dispersion characteristics of magnetostatic waves in a metal/ferrite/magnetic-wall structure are investigated. It is found that, in this case, the waves are characterized not only by a unidirectional propagation over the entire range of their existence (∼5 GHz) but also by the presence of a nearly straight section of the dispersion curve (∼2 GHz). In this structure, volume waves, surface waves, and waves with an amplitude that is constant over the plate thickness are seen to exist within the same frequency interval.