A Crossed S-shaped Frequency Selective Surface for Electromagnetic Wave Absorption With Excellent Angular Stability

In this paper, a frequency selective surface (FSS) for electromagnetic wave absorption with excellent angular stability is proposed. It is suitable for stealth applications with reflection characteristics at resonant frequency points. The FSS is attached to an FR-4 substrate which is backed with a conductive layer at the bottom. The unit cell structure consists of two S-shaped bars and four circles, which enables miniaturization of the absorber. The reflection characteristics of the surface element are analyzed by the full wave simulation. Analysis of transverse electric (TE) and transverse magnetic (TM) polarization modes and oblique incidence angle responses demonstrate that the proposed FSS ensures angle independence. The resonant mechanism is analyzed and an equivalent circuit model (ECM) is built. Finally, an experiment in the anechoic chamber is conducted to validate the simulation results.