Using Multiple Resonances to Widen the Band for High-Permeability Spiral-Pair Metamaterials

In this letter, we propose a new possibility to design a wider band for high-permeability material using metamaterial inclusions. A metamaterial formed by U-spiral-pair resonator with incremental variations in dimensions is proposed and analyzed. By optimizing its parameters, we create multiresonant responses that are close to each other. This can help to achieve high permeability over a wider frequency band. It is shown that the proposed design can achieve approximately up to 40% more bandwidth than the single-resonance material for effective permeability values above 2. The design, analysis, fabrication, and measurements showing widening the band with high permeability are presented. Results of full-wave simulations and experiments using waveguide measurements are compared.