An Ultra-Wideband Lightweight Absorber Based on Paper-Based Composites

This work presents a lightweight and ultra-wideband absorber, leveraging paper-based composites (PBCs) integrated with carbon fibers (CFs) through advanced paper-making techniques. The PBCs demonstrate high-frequency absorption capabilities, while low-frequency absorption is enhanced by extracting the PBC permittivity to determine the optimal absorber configuration. A planar impedance layer, comprising a hexagonal single-loop structure, is used to induce low-frequency resonances. The final combined structure, comprising PBCs and the impedance layer, achieves multimode resonance and exhibits a wide -10-dB reflection band from 2 to 18 GHz (160%). Experimental results confirm the outstanding performance of the absorber, featuring low density <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(50.7\ \text{kg}/{\mathrm{m}}^{3})$</tex> and wideband absorption.