Dual-band integrated self-biased edge-mode isolator based on the double ferromagnetic resonance of a bistable nanowire substrate

A dual-band integrated self-biased edge-mode isolator based on the double ferromagnetic resonance of a CoFeB ferromagnetic nanowire (FMNW) substrate, controllable by the geometrical and composition parameters of the FMNWs, is presented. The dispersion diagram of the FMNW edge-mode isolator, taking into account the effective permittivity and permeability of the FMNW medium, predicts two frequency bands of operation. These bands are demonstrated experimentally using FMNWs of 40 nm diameter with a lattice constant of 110 nm. In the presented prototype, isolations of 17 dB at 27.3 GHz and 4.4 dB at 31.2 GHz are observed under zero external applied field. The isolation of the second frequency band is increased to 18.3 dB by applying a small DC magnetic field of 0.13 T. The integrability, self-biased, double resonance, millimeter-wave and dispersion engineering properties of the FMNW medium opens up new possibilities for a diversity of magnetic devices and systems.