Unidirectional Magnetostatic Waves
  Dispersion characteristics of magnetostatic waves in tangentially magnetized to saturation ferrite film with a "magnetic wall" condition (tangential component of microwave magnetic field is equal to zero) on the one of the film surface were calculated. It is found, that unidirectional magnetostatic waves appear in this geometry: they can transfer energy only in one direction and fundamentally cannot transfer energy in an opposite direction. 
E.H. Lock, A.V. Vashkovsky (Institute of the Radio Engineering and   Electronics of Russian Academy of Science, Fryazino' de...