Negative refraction of really tunable reconstructed split-ring resonators and wires

A reconstructed split-ring resonator (SRR) and wire structure, in which each unit cell consists of two separate SRRs and a wire, is investigated in this paper. Numerical simulations exhibit the negative refraction of this structure. Simply shifting a substrate with one split ring, we can obtain the different negative-index bands. Combination of these bands forms a wider negative-index band. This structure is greatly flexible and really tunable, which is conducive to the design of microwave devices.