Optimization and fabrication of broadband metamaterial absorber using elliptical trust region based kriging surrogates

Abstract

This article provides a novel hyper-elliptic trust region optimization algorithm with kriging surrogates that is employed to obtain highly efficient designs of wideband metamaterial absorbers (MMAs) exhibiting high absorption with compact size. The introduced optimization algorithm is dynamically linked to the full vectorial finite element method to simulate the absorption performance of the investigated absorbers. To validate the capability of the proposed optimization technique, a previous MMA design with triangular resonators is re-optimized, achieving greater than 90% absorption across large frequency band from 10.9 GHz to 21.48 GHz, encompassing the entire Ku-band and significant portions of the X- and K-bands. Then, a novel MMA utilizing cross-shaped resonators is designed, analyzed, and successfully fabricated with exceptional absorption performance more than 90% over a broad spectrum from 14.18 GHz to 28.98 GHz for both transverse electric and transverse magnetic polarizations, covering a large part of the Ku-band, the entire K-band, and the lower part of the Ka-band. Further, a robust absorption performance (above 90%) could be achieved for a wide angular range (up to 40∘) for the studied design. Consequently, the formulated optimization technique is proven to be a highly effective tool for obtaining accurate and efficient designs of MMAs with perfect absorption characteristics.