基于双几何相位超表面的三频全空间波前调控

Tri-band Full-Space Wavefront Control Using Dual-Geometric-Phase Metasurface

为解决全空间超表面的多通道串扰问题,提出了一种基于双几何相位超表面的三频段透射-反射-透射全空间波前调控方法.采用频率选择表面与多层超表面子结构级联来获得三个频段的独立调控,并基于双几何相位原理实现了透、反射全空间幅相同调.为验证该方法的有效性,设计、加工并测试了一款工作于C,X,Ku三频段的圆极化全空间多功能超表面器件.仿真和实验结果均显示左旋圆极化波激励下该器件在7 GHz和10.2 GHz分别产生了沿y轴和x轴的透、反射双涡旋波束,而在15.7 GHz实现了双焦点透镜功能.该全空间多频幅相同调方法为新型多功能器件和集成电磁波调控提供了新思路,在大容量通信领域有广阔的应用前景.

To solve the problem of multi-channel cross-talk in full-space metasurface,a strategy of tri-band transmis⁃sion-reflection-transmission full-space wavefront control based on dual-geometric-phase metasurface is proposed.A fre⁃quency selective surface was cascaded with multilayer metasurface to obtain independent modulation of three frequency bands.The full-space independent amplitude and phase control combining transmission and reflection was realized based on dual geometric phase theory.For verification,a full-space multifunctional metadevice working at C,X and Ku bands was designed,fabricated and measured.Both numerical and experimental results show that transmissive and reflective du⁃al-vortex beams along y-axis and x-axis are generated at 7 GHz and 10.2 GHz,respectively,meanwhile dual foci along xaxis is generated at 15.7 GHz under left-handed circularly-polarized wave excitation.The proposed strategy of tri-band transmission-reflection-transmission full-space wavefront control provides new approaches for new multifunctional devices and integrated electromagnetic wave control,and expands the application prospect of metasurface in large-capacity commu⁃nication.