Neutral shells and their applications in the design of electromagnetic shields

Abstract

We present a simple design of electromagnetic shields for both field expelling and field confinement. Motivated by the concept of neutral inclusions in the theory of composites, we introduce two concepts of neutral shells, and use neutral shells to construct our designs of electromagnetic shields. We also discuss the relationships between electromagnetic shields and cloaking structures and argue that the designed shields are capable of ‘cloaking’ for plane waves in the long-wavelength limit.