Radiation‐Type Programmable Metasurface for Direct Manipulation of Electromagnetic Emission
Xudong Bai, Fuli Zhang, Li Sun, Anjie Cao, Xiaojun Wang, Fanwei Kong, Jin Zhang, Chong He, Ronghong Jin, Weiren Zhu, Tie Jun Cui
Abstract
Abstract Programmable metasurfaces enable fine‐grained real‐time modulation over electromagnetic (EM) waves in a digital manner, which have gained remarkable attention in antenna engineering and wireless communications. However, either a reflective or transmissive programmable metasurface requires an external feed source with significant distance to the metasurface, making the whole programmable device a relatively high profile as well as low efficiency as a result of the feed spillover losses. In this paper, an innovative design of radiation‐type programmable metasurface for dynamic modulation of radiant EM wave is presented, which perfectly combines the functions of 1‐bit phase shifter and efficient power radiator in the single unit framework. By employing the integrated series‐parallel hybrid microstrip network to stimulate the topside metasurface units, versatile capacities, including dynamic beam scanning and multimode vortex beam generation, are verified both numerically and experimentally. Due to the direct‐radiation characteristic of the metasurface design, the programmable metasurface possesses the aperture efficiency over 30% and a low profile reduced by almost two orders of magnitude, when comparing with the conventional reflective or transmissive programmable metasurfaces illuminated by the external feeds. The proposed design can offer a novel approach of programmable metasurface framework in dynamic radiant EM modulation for low‐profile conformal applications.