Design of ultrawideband metamaterial absorber with enhanced optical transparency utilizing laser etching ITO micromesh.

Abstract

Metamaterial absorbers demonstrate significant application potential in radar stealth and electronic communication fields. However, achieving the synergistic optimization of high optical transmittance and excellent absorption performance in absorbers remains a critical challenge. This paper proposes an ultra-wideband optically transparent metamaterial absorber, innovatively introducing periodic unit cells with indium tin oxide (ITO) micromesh. By employing an equivalent parallel mesh structure, this design refines the line width of the ITO film and stabilizes the equivalent inductance, thereby substantially enhancing both the optical transparency and visual performance of the metamaterial absorber. Based on an equivalent circuit model and genetic algorithm (GA), this design method enables rapid synergistic optimization of broadband microwave absorption and high optical transparency across multiple absorption layers. Simulation and experimental results demonstrate that the fabricated sample achieves a reflection coefficient below -10 dB from 2.90 to 19.94 GHz, covering the entire C, X, and Ku bands. The relative absorption bandwidth reaches 149%. Moreover, the structure exhibits high angular stability and polarization insensitivity, with an average optical transmittance exceeding 80% in the visible light region. This study offers a high-performance solution for radar stealth and electromagnetic compatibility (EMC) in optical windows.