A Lightweight Ultra-Wideband Metasurface Microwave Absorber

Wideband microwave absorbers hold significant importance in both civilian and military fields. In this paper, a lightweight ultra-wideband metasurface microwave absorber that covers a frequency range from the ultrahigh-frequency band to Ku band is presented. The absorber consists of three layers of periodically arranged fourfold rotationally symmetric indium tin oxide (ITO) patterned structures and a reflective surface at the bottom layer separated by polymethacrylimide (PMI) spacers. Such a design enables the absorber to achieve a lightweight construction. The experimental results demonstrate that the absorber exhibits an absorptivity >90% in the 1.3-13.3 GHz band, with a corresponding fractional bandwidth of up to 164.4%. Additionally, the designed absorber features a remarkably lightweight performance with volume density relative to wavelength (VDRW) of just 6.71 mg cm(-3). Furthermore, attributed to its fourfold rotationally symmetric design, the absorber also exhibits polarization insensitivity and excellent angular stability. These unique properties render the proposed wideband absorber highly suitable for a variety of practical applications after reasonable adjustment and optimization.