Possibility of superheterodyne amplification of magnetostatic waves in ferromagnets

A superheterodyne mechanism for the amplification of magnetostatic waves in plates and films of ferromagnetic materials, yttrium iron garnet in particular, is proposed. The mechanism involves the transfer of acoustoelectronic amplification from a sound wave to one of two oppositely directed magnetostatic waves, with which the sound wave is interacting parametrically. Approaches to practical implementation of the mechanism are also discussed. The efficiency of the mechanism is evaluated for the case of a ferromagnetic plate magnetized in the direction perpendicular to its surface; it is demonstrated that superheterodyne amplification of magnetostatic waves is relatively efficient over a broad frequency range.