Design of Multi Liquid‐Based Ultra Broadband Metamaterial Absorbers With Multilayer Architected Resonances

The limited absorption performance of single‐liquid metamaterial absorbers within the S and C bands remains a significant challenge. To address this issue, this paper proposes a multi‐liquid‐based ultra‐broadband metamaterial absorber featuring three architectured resonant layers. A genetic algorithm is employed to simultaneously optimize both liquid material selection and structural parameters within a three‐layer framework comprising cross‐shaped, annular ring, and triple‐anchor resonant structures. The optimized design achieves effective absorption from 3.65 to 31 GHz, notably extending into the S band and thereby overcoming previous limitations below 6 GHz. The multi‐liquid strategy capitalizes on the complementary dielectric properties of water and ionic liquids, enabling continuous broadband impedance matching through synergistic interlayer coupling. Experimental validation demonstrates good agreement with simulation results. This intelligent optimization approach, combined with multi‐liquid architectured resonances, offers a generalizable strategy for the design of next‐generation broadband electromagnetic wave absorption metamaterials.