A tunable double negative device consisting of a plasma array and a negative-permeability metamaterial

Extraordinary wave transmission is demonstrated through a double-negative composite comprised of a negative-permeability array of double split ring resonators and a negative-permittivity array of plasma discharge tubes at microwave frequencies. A transmission peak emerges in a double-negative band and controlling the electron density inside the plasma tubes dynamically regulates the transmission properties. By performing experiments and theoretical calculations, we verify that the composite permits wave propagation with negative permeability and controllable permittivity, which indicates that a tunable negative-refractive-index device is achieved. Published under license by AIP Publishing.