Reconfigurable Huygens’ Metasurface for Real-Time Orbital Angular Momentum Tuning and Beam Scanning

A planar single-substrate electronically reconfigurable Huygens’ metasurface (HMS) embedded with PIN diodes is proposed in this paper, featuring high transmission coefficient, ultrathin thickness, and 1-bit dynamic phase responses at microwave frequency. The HMS meta-atom comprises a pair of dislocated I-shaped dipoles printed on both sides of a dielectric substrate without metallic vias. This configuration generates equivalent electric and magnetic dipole resonances, which jointly fulfill the Huygens’ principle, thereby enabling high-effiency transmission and precise phase control manipulation. Each Huygens element includes two PIN diodes, which are simultaneously switched ON or OFF to achieve 0° or 180° phase states, respectively. To showcase the dynamic electromagnetic wave control ability, a HMS prototype with a thickness of only 0.058λ0 is designed and fabricated. Firstly, orbital angular momentum (OAM) beams with switchable modes are realized by the proposed reconfigurable HMS. Secondly, the beam-steering capabilities as a transmitarray antenna (TA) at 5.84 GHz are experimentally validated over a wide-angle range from 0° to 60° with improved scan losses. The proposed reconfigurable HMS may have potential uses in high-capacity wireless communications, intelligent radar systems, and adaptive remote sensing via versatile wavefront control and dynamic mode switching.