Ultra-broadband and wide-angle microwave absorber based on resistive films with a 3D configuration

Abstract

This paper introduces a broadband electromagnetic wave absorber with characteristics of polarization-independence and wide-angle stability based on resistive films with a three-dimensional (3D) configuration. The absorber consists of a 3D dielectric substrate array covered by a resistive film, which not only broadens the operation frequency band but also improves the absorption with large incidence angles. Simulated results indicate that the absorber achieves wideband absorption with over 90% absorptivity in the frequency range of 5.7–41.8[Formula: see text]GHz, corresponding to a relative absorption bandwidth of 152%. Due to the high symmetry of the structure, the absorber is insensitive to polarization angles. Moreover, the presented design maintains wave absorption greater than 90% when incidence angle reaches 70∘ due to its 3D structure that ensures high absorption for wide incidence angles. The mechanism of this structure is investigated through surface current and power consumption distribution, while optimization parameters are analyzed for achieving the desired bandwidth. This absorber has the advantages of wide-band absorption and excellent stability under oblique incidence angles, making it potentially useful in applications such as electromagnetic shielding and energy harvesting.