A dual‐stopband FSS using knitted and strong‐coupled structures with excellent angular stability and polarisation insensitivity

Abstract

In this paper, a novel dual-stopband frequency selective surface (FSS) based on the knitted and strong-coupled structures is proposed. The proposed FSS works stably at frequencies of 2.51 and 5.06 GHz for both TE and TM mode, even when the incident angles vary from 0° to 75°. The element size and thickness of the proposed structure are λ0/16 and λ0/170, respectively, where λ0 represents the free-space wavelength. To clarify the operating principle, a general equivalent circuit model (ECM) is developed. A prototype of the proposed FSS is fabricated and measured. It is demonstrated that the proposed structure has good angular stability, polarisation insensitivity, and independent operation in the dual-stopband. Importantly, the proposed structure has good prospects for application in dual-band electromagnetic shielding in complex environments.