Tunable dual-band negative refractive index metamaterial consisting of ferrites and SRR-wires

In this paper, we present a tunable dual-band negative refractive index metamaterial (NRIM), which composed of ferrite slabs, split ring resonators (SRR), and continuous wires. Numerical simulation shows that two pass-bands could be found in such structure, and the dual-band negative refractive indexes are demonstrated with the retrieved effective parameters based on the simulated scattering parameters. Taking advantage of the tunable permeability of ferrite slabs, we show these two negative refractive index passbands can be dynamically tunable by simply changing the magnetic bias