Multiband Chiral Metasurface for Asymmetric Reflection and Transmission of Circularly Polarized Waves

This letter presents an ultrathin planar bilayered chiral metasurface (MS), which exhibits direction dependent reflection and direction dependent transmission of incident circularly polarized waves within five frequency bands. The five operational frequency bands lie within 5.55–5.78 GHz, 6.1–6.23 GHz, 10.42–10.68 GHz, 11.06–11.17 GHz, and 12.03–12.18 GHz, respectively. The MS can therefore be used for C, X, and Ku microwave band applications. Within the five asymmetric reflection bands, the MS acts as a metamirror where the handedness of the incident and reflected circularly polarized waves remain unchanged with respect to an observer. The response of the MS is stable for incident angles up to 45° for the first four bands and 30° for the final band. This makes it useful even for oblique incidence.