Low-loss and multi-band metamaterials

Low-loss metamaterials based on fishnet and concentric open-ring configurations are reviewed in terms of design, fabrication, and characterization. It is observed both numerically and experimentally that the proposed metamaterial configurations have low-loss and a negative index of refraction at around the resonance frequency. The effective constitutive parameters are analysed for the characterization of the bulk nature of the proposed metamaterials. Finally, different ways to design low-loss metamaterials for different frequency regimes to be used in several potential applications are also addressed.