yijun feng

Time-varying Coding Metasurface and Its Potential Application in Wireless Communication

Metasurfaces, the two-dimensional artificial materials or structures, have recently attracted unprecedented research interests due to their powerful ability of manipulating electromagnetic (EM) wave and realizing many exotic physics phenomena and novel devices. In addition, active metasurfaces can be elaborately designed by incorporating tunable materials or components, such as diodes, liquid crystal, or graphene, to enable dynamic control of EM waves. By controlling the external stimulation, for example, bias voltages, the active elements in the metasurface can be dynamically tuned locally with time through a pre-designed manner to trigger different time-varying wave responses of the metasurface. Recently, the reconfigurable Intelligent surface (RIS), which is a kind of time-varying coding metasurface, has been recognized as one of the key technologies of B5G/6G wireless communication to achieve intelligent and efficient control of wireless communication channels. In this talk, I will briefly introduce the design methods and implementations of active and time-varying metasurfaces. Then I will show examples of utilizing time-varying coding metasurface to realize new wireless communication architecture with direct information modulation on the scattering signals from the metasurface. Finally, through design and implementation of a 2-bit RIS prototype, I will showcase its potential in optimizing and enhancing in-door 5G wireless signal coverage and verify the feasibility of applying RIS in real wireless network environment.

Acknowledgements: This work is supported by National Natural Science Foundation of China (NSFC) (91963128, 62071215, 61801207, 61871394), and National Key Research and Development Program of China (2017YFA0700201).

Yijun Feng received the Ph.D. degrees from the Department of Electronic Science and Engineering, Nanjing University, in 1992. Since then he has been a faculty member and is currently a full professor and the Deputy Dean of the School of Electronic Science and Engineering, Nanjing University. From September 1995 to July 1996, he was a visiting scientist with the Physics Department, Technical University of Denmark. From August 2001 to August 2002, he was a visiting researcher with the University of California at Berkeley. Prof. Feng’s research interests include the electromagnetic metamaterial and application to microwave and photonic devices, electromagnetic wave theory, and novel microwave functional materials. He has conducted more than twenty scientific research projects including National 973, 863 Projects, the National Natural Science Foundation projects and the National Key Research and Development Program in China. He has received the 2010 Science and Technology Award (First grade) of Jiangsu Province, and the 2021 Science and Technology Award (First grade) of Shanxi Province, China. He has authored or co-authored over 200 peer-reviewed journal papers including in Science, Adv. Mater., Phys. Rev. Applied, Appl. Phys. Lett., Opt. Lett, IEEE TAP, IEEE AWPL, etc, and over 150 referred international conference papers.