Cross-Junction Based Metasurface for Wideband 90° Polarization Rotation

In this work, an ultrathin subwavelength metasurface based on a cross-junction-inspired unit cell that exhibits efficient wideband polarization rotation is presented. This structure manipulates the polarization of the incident electromagnetic radiation in the transmission band. The proposed metasurface converts the incident linearly polarized waves into the orthogonal polarization over a fractional bandwidth of 9.6% with a maximum insertion loss of 0.65 dB. The detailed analysis of the structure’s inherent resonances and their origins are also presented with special emphasis on the intrinsic Fano resonances (FRs) of the proposed unit cell and their evolution by introducing structural asymmetry. A prototype of the proposed design is fabricated and characterized, and the results show very good agreement with numerical simulations.