A Bilateral Coding Metabsorber Using Characteristic Mode Analysis

Abstract

Coding is an effective method of designing wideband metabsorber, but the resultant metabsorbers are usually associated with complicated shapes that hinders clear physics understanding of the wideband principle behind the scene. This study presents characteristic mode analysis (CMA) of two types of coding metabsorber composed of single-layer and bilateral resonators, respectively, generated by the genetic algorithm optimization methods. Compared with the conventional single-layer design, CMA results illustrate the wideband principle of the bilateral design introducing additional absorption modes. With a fractional bandwidth of 143.5%, the proposed bilateral metabsorber measures an absorption bandwidth of 5.9–35.9 GHz for 90% absorptance. CMA provides a low-threshold method to analyze the metabsorber with complicated resonators, thereby paving the way for the physical-oriented coding optimization improvement.