MULTI-BAND NEGATIVE REFRACTIVE INDEX IN FERRITE-BASED METAMATERIALS

A multi-band ferrite-based metamaterial has been investigated by experiments and simulations. The negative permeability is realized around the ferromagnetic resonance (FMR) frequency which can be influenced by the saturation magnetization 4πMs of the ferrites. Due to having multiple negative permeability frequency regions around the multiple FMR frequencies, the metamaterials consisting of metallic wires and ferrite rods with various 4πMs possess several passbands in the transmission spectra. The microwave transmission properties of the ferrite-based metamaterials can be not only tuned by the applied magnetic field, but also adjusted by the 4πMs of the ferrite rods. A good agreement between experimental and simulated results is demonstrated, which confirms that such a ferrite-based metamaterial possesses a tunable multi-band behavior. This approach opens a new way for designing multi-band metamaterials.