A High-Performance Ultra-Broadband Transparent Absorber With a Patterned ITO Metasurface

Abstract

A high-performance microwave absorber with simultaneously ultra-broadband microwave absorption, mechanical flexibility and high optical transparency is proposed. A patterned indium-tin-oxide (ITO) conductive metasurface is used as the upper surface resonance layer. ANSYS HFSS 15.0 was used for the infinite period structures of the absorber simulation, and the Floquet port, master-slave boundary condition and adaptive meshing were set in the software. As a result, the absorber features >90% broadband absorption, which covers a wide frequency range of 17.6 GHz (21.6-39.2 GHz) and includes part of the K and Ka frequency bands. What is more, the absorption is above 99% in the range from 30 GHz to 33.6 GHz. The optical transmittance of the absorber in the visible light band is 85%. The thickness of the absorber is only 0.1 times of the wavelength corresponding to the lowest absorption frequency (13.89 mm). Furthermore, the absorber maintains stable absorption at different incident and polarization angles due to the quadruple centrosymmetric pattern.