- Letter
Ultrabroadband transparent metamaterial absorbers designed by anomalous Brewster effect and gradient impedance matching optimized with deep neural network
Phys. Rev. Applied 23, L051002 – Published 19 May, 2025
DOI: https://doi.org/10.1103/PhysRevApplied.23.L051002
Abstract
Transparent microwave absorbers are important in many scenarios. In this work, we theoretically and experimentally demonstrate a class of transparent metamaterial absorbers as a lattice of wedgelike or pyramidlike multilayered indium tin oxide films embedded in a transparent dielectric slab, exhibiting high absorption within two broad frequency bands from 2.5 to 17.7 GHz and from 21.1 to 40.0 GHz. This high-efficiency absorption originates in the anomalous Brewster effect and gradient impedance matching. Moreover, through optimization with deep learning, the absorption bandwidth (with average absorption >93%) can be further extended to cover the whole regime from 1.7 to 40.0 GHz. The designed transparent metamaterials with broadband high-efficiency microwave absorption promise a wide range of applications such as special windows for electromagnetic shielding and stealth.
