Design and fabrication of an all-composite ultra-broadband absorbing structure with superior load-bearing capacity

With the rapid development of electronic information technology, there has been an increasing demand for lightweight multifunctional microwave absorption structures in aerospace and marine applications. In this work, a novel curved-walls composite honeycomb structure (CWCHS) composed of quartz fiber reinforced composite (QFRC), chopped carbon fiber/glass fiber composite felt (CCF/GFC) and carbon fiber reinforced composite (CFRC) was designed. Multi-scale optimization was carried out to achieve both ultra-broadband absorption and superior mechanical performance. Analytical model of absorption characteristic and mechanical properties were also constructed. The −10 dB absorption bandwidth (90% absorptivity) of the proposed CWCHS achieves 38 GHz (2-40 GHz, containing S, C, X, Ku, K and Ka bands) with an average reflectivity of −16.5 dB (98% absorptivity). Moreover, the absorption performance of the CWCHS shows excellent angle stability within 40° incidence angle. The CWCHS exhibits a remarkable load-bearing capacity, with strength of 31.3 MPa at a density of 0.21 g/cm3. Overall, the proposed CWCHS provides a promising approach for the development of lightweight multifunctional absorption structure and has potential applications in the new generation of inlet grilles and integrated skins.