Smart Graphene-Based Frequency Selective Surface Designed to Act as Single or Dual Band Device with Reconfigurable Operation Bands

Abstract In this paper, a finite-difference time-domain (FDTD) formulation, based on the exponential matrix and on thin material sheet methods is developed for modeling subcellular thin graphene sheets. This formulation is validated by reproducing graphene frequency selective surfaces (FSS) known from literature. Then, we propose in this work a smart graphene FSS device. Smartness is obtained by means of a unity cell formed by a graphene ring with a graphene sheet placed in its aperture. By properly regulating the chemical potentials of the graphene elements, two frequency- tunable modus operandi are obtained: single- or dual-band rejection modes. When the device operates in its dual-band rejection mode, either of the rejection bands can be shifted individually in the frequency spectrum. Additionally, both rejection bands can also be reconfigured simultaneously.

摘要 本文针对亚细胞级超薄石墨烯片的建模问题，提出了一种基于指数矩阵与薄材料片方法的时域有限差分（finite-difference time-domain, FDTD）方法。该方法通过复现文献中已报道的石墨烯频率选择表面（frequency selective surfaces, FSS）的电磁特性完成了有效性验证。随后，本文提出一款智能型石墨烯FSS器件：该器件的智能特性通过一款单元胞实现，该单元胞由石墨烯环构成，其孔径内嵌一片石墨烯片。通过精准调控各石墨烯结构单元的化学势，可获得两种频率可调的工作模式：单频带抑阻模式与双频带抑阻模式。当器件工作于双频带抑阻模式时，两个抑阻频段可分别在频谱中独立偏移；此外，两个抑阻频段也可同时进行重构调谐。