Digital Coding Metasurfaces: Toward Programmable and Smart Manipulations of Electromagnetic Functions

Abstract

Digital coding metasurfaces are an important research branch of metamaterials and metasurfaces. The digital coding method replaces the equivalent medium theory to characterize metasurfaces, which not only simplifies the design process of metasurfaces but also builds a bridge between digital information and metasurface physics. The development of digital coding metasurfaces is systematically summarized in this review, and latest research progress of digital coding metasurfaces toward programmable and smart ElectroMagnetic (EM) manipulations is highlighted. First, the basic concept of digital coding metasurfaces and corresponding research in information theory are thoroughly explained. Next, the working principle, realization method, and different research directions of programmable metasurfaces are detailed, including radiation-type programmable metasurfaces, multidimensional programmable metasurfaces, time-domain digital coding metasurfaces, and new wireless communication systems. The recent research on smart metasurfaces is then introduced, and their capabilities of environment sensing and adaptive EM manipulation are demonstrated. Finally, the future development and prospects of metasurfaces are also discussed.

Keywords

• metamaterials
• metasurfaces
• electromagnetic functions
• digital coding
• programmable manipulation
• smart manipulation