All-nickel-coated glass fabric honeycomb sandwich composite for robust and lightweight radar absorption

In this study, a radar-absorbing honeycomb core sandwich structure (RAHSS) was developed to simultaneously achieve high radar-absorbing performance, structural load-bearing capability, and weight efficiency in radar-absorbing structures (RASs). By employing nickel-coated glass fabric as both the face sheets and honeycomb core, the proposed RAHSS simultaneously achieves enhanced electromagnetic attenuation, improved mechanical performance, and significant weight reduction compared to conventional laminate-type RASs. The glass fabric was uniformly coated with nickel via electroless plating to tailor its electromagnetic properties, and the surface characteristics of the resulting fabric were systematically analyzed using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The electromagnetic design of the RAHSS was optimized using CST Microwave Studio, and its radar-absorbing performance was experimentally evaluated through reflection loss (RL) and radar cross-section (RCS) measurements. The mechanical performance of the RAHSS was assessed through three-point bending tests and directly compared with that of a laminate-type RAS fabricated from the same constituent materials. Results demonstrate that the RAHSS effectively attenuates incident electromagnetic waves over a target frequency range and achieves substantial backscattered signal reduction compared to a perfect electric conductor. It exhibits a load-to-weight ratio approximately 2.2 times higher than that of the laminate-type RAS, confirming its superior bending efficiency. Overall, the proposed RAHSS offers a lightweight, mechanically robust, and electromagnetically efficient solution for next-generation stealth structures in aerospace and defense applications.