Compact Single Resonator Dual-Band FSS Absorber with Wider Angular Stability for C and Ku Bands

This paper presents a novel dual-band frequency selective surface (FSS) absorber designed for high absorption performance at 5.2 GHz and 16.9 GHz, with 99.3% and 99.5% absorption coefficients, respectively. The proposed structure exhibits polarization insensitivity, maintaining a stable absorption response for both TE and TM modes. Additionally, it demonstrates excellent angular stability, effectively sustaining its performance up to oblique incidence angles of 60<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup>. Analyzing the surface current distribution helps demonstrate the electromagnetic behavior observed at the resonant frequencies. The unit cell is highly compact, with an individual cell size of 0.20 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> ×0.20 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> , where λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> is the free space wavelength. The proposed FSS absorber is well-suited for radar cross-section (RCS) reduction, stealth applications, and electromagnetic shielding.