Broadband Beam-Scanning Metasurface With Rotatable Phase Shifting Surface

Abstract

Fresnel zone plate (FZP)-phase shifting surface (PSS)-based metasurface design techniques have demonstrated advantages in mechanical beam-scanning antenna design. However, mechanical beam-scanning metasurfaces based on PSS are typically limited to narrowband operation and lack broadband capabilities in high millimeter-wave frequencies. To address the limitations of mechanical beam-scanning metasurfaces, a novel high-frequency design approach is proposed, which incorporates hybrid unit cells exhibiting high transmission amplitude and a 60° phase difference across the broadband range. By integrating a combination of identical and nonidentical unit cells, the proposed design enables the realization of arbitrary transmission phase ranges with reduced design complexity. Furthermore, an analysis of the metal layer structure reveals that the introduction of additional resonance variables enhances phase difference stability in the broadband range. A PSS-based broadband mechanical scanning scheme is first proposed in the W-band, which is easy to integrate and has low processing costs. The beam-scanning metasurface predicated on this broadband PSS design achieves a 3-dB gain bandwidth of 20%, offering a promising solution for W-band wireless communication system.