Ultra-broadband extreme absorption in an optically transparent metasurface with superior adaptability

To address the growing demand for microwave absorbers featuring broad bandwidth, high absorption, and environmental adaptability, this study proposes a microwave absorber based on an optically transparent metasurface with superior adaptability. The absorber adopts a stratified configuration, the core of which is a fixed patterned resistive layer. By optimizing the materials and thicknesses of the upper and lower substrates, it achieves extreme absorption exceeding 99% for both transverse electric (TE) and transverse magnetic (TM) polarizations over an ultra-broad bandwidth of 8.8–28.6 GHz (a fractional bandwidth of 105.9%), while maintaining stable performance at incidence angles up to . Another notable advantage of the proposed design is its superior substrate compatibility, enabling the direct use of readily available environmental materials such as wood and paper as substrates. This versatility enables the absorber to be lightweight, flexible, or optically transparent, while simultaneously achieving excellent electromagnetic absorption, visual concealment, and environmental integration. These combined features establish the proposed absorber as a highly practical solution for future military platforms, including transparent radomes, stealth unmanned aerial vehicles, and wearable camouflage systems.