ABSTRACT This article proposes a dual‐polarization broadband frequency selective rasorber (FSR) based on a composite metasurface structure, achieving ultra‐wide absorption bands on both sides of the transmission band. The vertically stacked configuration consists of a lossy layer and a frequency selective surface (FSS) layer. The top lossy layer uses compact electric resonators with coupling capacitors, while the lower FSS layer features a Jerusalem cross‐slot structure, both designed to enhance absorption bandwidth. To elucidate the underlying physical mechanism, an accurate equivalent circuit model (ECM) is established, combined with surface current distribution analysis to interpret the absorption behavior. Simulation results show that the proposed FSR achieves a dB reflection band over 3.68–16.94 GHz with a fractional bandwidth of 128.6%, featuring a minimum insertion loss of 0.3 dB at 10.3 GHz. The design achieves the widest low‐reflection bandwidth among reported two‐layer FSRs without increasing structural complexity. A prototype was fabricated and measured, showing reasonable agreement with simulations. The proposed FSR exhibits potential in broadband stealth radomes and anti‐interference systems.
Yu et al. (2025) studied this question.