Composite medium with simultaneously negative permeability and permittivity

We demonstrate a composite medium, based on a periodic array of interspared conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeability mu(eff) (omega) and permittivity epsilon(eff)(omega) This structure forms a left-handed medium, for which it has been predicted that such phenomena as the Doppler effect, Cherenkov radiation, and even Snell's law art inverted. It is now possible through microwave experiments to test for these effects using this new metamaterial.