Lightweight broadband electromagnetic wave absorber based on a three-dimensional pixel-optimized honeycomb structure

Abstract

Broadband electromagnetic wave absorbers are essential for enhancing the survivability of next-generation stealth platforms operating in multiband radar environments. In this study, a three-dimensional (3D) pixelated honeycomb absorber is designed, optimized, and fabricated to achieve high absorption efficiency at a limited thickness while maintaining an ultralightweight nature and structurally integrable characteristics via direct pixel implementation on honeycomb cell walls. Conductive ink patterns are printed directly onto the aramid honeycomb cell walls according to a pixelated arrangement optimized using a genetic algorithm. The optimized 20-mm-thick structure exhibits a density of approximately 50.6 kg/m³, slightly higher than that of the pristine aramid honeycomb (47.8 kg/m³), confirming that it retains its lightweight nature. Experimental results reveal the structure’s broadband absorption performance, exhibiting a −10 dB reflection loss bandwidth covering a substantial portion of the 1–18 GHz range, despite the single-layer configuration and nonmagnetic composition. A comparative analysis reveals that doubling the thickness to 40 mm while maintaining the same pixel design results in limited performance improvement, underscoring the decisive role of the proposed 3D pixel optimization approach in mitigating the conventional thickness–bandwidth trade-off. The developed absorber design provides structural scalability, manufacturing consistency, and adaptability to various platforms, indicating strong potential for practical applications in composite structures for preparing stealth aircraft air inlets, weapon systems, and unmanned aerial vehicles.