Realizing an ultra-wideband backward-wave metamaterial waveguide (article)

This is the final version. Available from American Physical Society via the DOI in this record. The dataset associated with this article is in ORE at https://doi.org/10.24378/exe.944Electroinductive waves have emerged as an attractive solution for designing metamaterials that support backward propagating waves. Stacked metasurfaces etched with complementary split-ring resonators (CSRRs) have also been shown to exhibit a broadband negative dispersion. We demonstrate, through experiment and numerical modeling, that the operational bandwidth of a CSRR metamaterial waveguide can be improved by restricting cross-polarization effects in the constituent meta-atoms. We report a fractional bandwidth of >56%, which, to the best of our knowledge, is broader than any previously reported value for an electroinductive metamaterial. We present a traditional coupled-dipole toy model as a tool to understand the field interactions in CSRR-based metamaterials, and to explain the origin of their negative dispersion response.Engineering and Physical Sciences Research Council (EPSRC)European Research CouncilQinetiQ Lt