New high-power magnetically tunable microwave filter

The magnetic-field-dependent dispersion and low loss exhibited by spin waves propagating through ferrimagnetic materials, in the electromagnetic region of their spectrum, permit the construction of tunable microwave interference filters bearing a close analogy to the optical Fabry-Perot étalon. Since this approach avoids a strong coupling of energy into the electron-spin dipoles at their uniform-precession resonance frequency, the power levels required to produce nonlinearities in the filter response are in excess of 1 kW.