On the Design of Multibeam Digital Metasurfaces With Multiple Feeds. Issue 2 (15th December 2022) - Rezaee Rezvan, Behrad
Abstract: In this paper, an analytical design procedure for multibeam metasurfaces with multiple feeds is presented. Considering arbitrary number of input and output beams, the required amplitude and phase distributions on the metasurface plane are theoretically derived without any optimization process. How the limitation of using only passive metasurfaces poses different challenges in the practical implementation of the amplitude profile is discussed. Then, to resolve these problems, a filtering procedure is proposed which effectively produces the desired output pattern. Moreover, the design method is verified through introducing a reflective metasurface with three input beams and sixteen output beams in arbitrary directions. It utilizes a graphene‐based unit cell providing simultaneous 2/2‐bit phase/amplitude modulation, that is, totally 16 states. For validation purposes, the analytical results are compared with numerical full‐wave simulation ones in which a good agreement between them is observed. In addition, by using the proposed design method, three different practical cases for wave manipulation functionalities, including power control, beam steering, and radar cross section (RCS) reduction capabilities are demonstrated. The presented approach paves the way for efficient design of the metasurfaces for a multitude of applications, including reconfigurable intelligent surfaces and multifunctional surfaces. Abstract : A design algorithm for a metasurface that can convert L incident waves into K reflected waves is presented. The state matrix specifies one predefined state to amplitude and phase value of each unit cell. The proposed unit cell has two graphene layers and can provide 2/2‐bit phase/amplitude states using the voltage dependent conduction of each graphene layer.