Broadband Electromagnetic Wave Absorbing Structure Inspired by Air Dielectric Capacitors with Reconfigurable Potential

Impedance matching and loss capability are two critical factors in evaluating electromagnetic wave absorbing materials. However, decoupling and enhancing both impedance matching and loss capability within a limited thickness remains a significant challenge. To address the issue, inspired by the design of air dielectric capacitors in radios, this study developed a rotationally symmetric discrete porous SiC-based metamaterial (RSDP-SiC). By adjusting the structural parameters of RSDP-SiC, the optimized structure demonstrates over 90% absorption in 4–18 GHz with an ultra-low surface density of 0.102 g cm⁻². Additionally, this material exhibits insensitivity to the angle of incidence. This work may pave the way for the future development of a new generation of efficient, lightweight, broadband, and reconfigurable electromagnetic wave absorbing materials.