An ultra-broadband multi-layer dielectric gradient honeycomb microwave absorber enhanced by the double layer metasurface

Abstract

A novel, 12 mm multilayer dielectric gradient honeycomb absorber (MGHA) was designed, fabricated and analyzed with a double layer metasurface consisting of a resistive film and an artificial magnetic conductor (AMC) checkerboard. Despite its thin profile, the MGHA demonstrates significantly enhanced absorption performance across a wide frequency range due to the impedance of the composite structure. Furthermore, two distinct metasurfaces are integrated into the dielectric gradient multilayer honeycomb absorber to further enhance its low-frequency properties without increasing thickness. This structure exhibits wideband absorption from 2.8 GHz to 18 GHz, featuring three absorption peaks at 3 GHz, 11 GHz and 16 GHz. The relative bandwidth can reach nearly 136.6 % of that achieved by a common honeycomb absorber with the same thickness, while maintaining an absorption peak reflection of about −22dB. The great attenuation of incident waves is attributed to Ohmic loss on the resistive film, electric resonance effect on the checkerboard, and magnetic resonance near 17 GHz on the checkerboard metasurface. The proposed MGHA structure holds significant potential for applications in aerospace and military.