Metamaterial transmission lines based on split-ring resonators (SRRs) and complementary split-ring resonators (CSRRs)

Microstrip line periodically loaded with split-ring resonators (SRRs) and complementary split-ring resonators (CSRRs) is designed. By utilizing the CSRRs/gaps and SRRs/inductances combinations, two passbands are observed. Because of the negative permeability offered by SRRs and series capacitances, the negative permittivity offered by CSRRs and shunt connected wire (or via) inductances, the structure can also be considered as metamaterial transmission line. Namely, the structure supports backward-wave propagation in the vicinity of its resonance frequencies. A prototype metamaterial transmission line is fabricated and the measurements agree well with simulations.