Broadband and dual-polarized electromagnetic transparency at large angles based on phase and impedance regulation of fishbone metasurfaces

Abstract

Electromagnetic (EM) transparency at large incident angles is of great necessity in many applications. Here with the theoretical analysis as the guidance, we have designed a fishbone metasurface for dual-polarized and broadband EM transparency at large angles. It works for transverse-magnetic (TM) polarization by phase regulation, when for transverse-electric (TE) polarization by impedance regulation. For a ceramic-matric-composite (CMC) plate, the metasurface could improve both of its TM and TE polarized transmission obviously in the whole Ku band, at incident angles of 70 $°$ ∼85$°$. And the bandwidth with dual-polarized transmission both $>$-1dB exceeds 2.8 GHz, which is pretty excellent compared with other related works. The performance has been validated through both simulation and measurement, where the measured result is basically consistent with the simulated one. Meanwhile, the metasurface's working mechanism has been verified to be in accord with the theoretical analysis. Additionally, its robustness against processing errors, the designability to plates' thicknesses and incident angles, and the performance for actual antennas all have been validated, which indicates great application potential. In summary, the fishbone metasurface proposed here may provide new ideas for EM transparency, and find wide applications in communication, radar, and others.