Compact dual-band independently modulated bifunctional full-space metasurface

In this paper, a bifunctional full-space metasurface (FS-MS) with dual-band is proposed. Two metal layers are located on each side of the unit dielectric substrate, independently regulating the phase in the transmission and reflection. The metasurface can reflect x-polarized waves at 28 GHz and transmit y-polarized waves at 35 GHz. Based on the anisotropy and Huygens theories, the reflected and transmitted beams can be tuned flexibly. The metasurface design is carried out as an illustration of the reflected Bessel beams and the transmitted focusing or OAM beam. The results show that the metasurfaces can realize double zero-order Bessel beams, bifocals with a focusing efficiency of 22.27%, and an OAM beam with a mode purity of 74.12%. The proposed FS-MS, devoid of multilayer stacking and metal perforations, exhibits a simple structure, low profile, and ease of processing, all of which make them a promising candidate for applications in intelligent housing systems.