Magnetically tunable Fano resonance with enhanced nonreciprocity in a ferrite-dielectric metamolecule

Abstract

A magnetic tunable Fano-resonant metamaterial structure with enhanced nonreciprocity at microwave frequencies has been designed and investigated. The metamolecule has been implemented by using a dielectric cube and a magnetically biased ferrite. The Fano resonances originate from mode coupling between two constituents. The structure possesses a nonreciprocal feature since the external field breaks the time-reversal symmetry, and the Fano-type interference further enhances the nonreciprocal nature of biased ferrite. We are able to manipulate the Fano modes by adjusting the applied magnetic field. Simulation results suggest that the proper permittivity of the dielectric cube will optimize the nonreciprocal contrast. The magnetically tunable feature of the proposed metamaterial can potentially be applied to design dynamically controlled switches and isolators.