Abstract: High-temperature microwave absorbing materials (MAMs) and structures are increasingly appealing due to their critical role in stealth applications under harsh environments. However, the impedance mismatch caused by increased conduction loss often leads to a significant decline in electromagnetic wave absorption (EMWA) performance at elevated temperatures, which severely restricts their practical application. In this study, we propose a novel approach for efficient electromagnetic wave absorption across a wide temperature range using reduced graphene oxide (RGO)/epoxy resin (EP) metacomposites that integrate both electromagnetic parameters and metamaterial design concepts. Due to the discrete distribution of the units, electromagnetic waves can more easily penetrate the interior of materials, thereby exhibiting stable microwave absorption (MA) performance and impedance-matching characteristics suitable across a wide temperature range. Consequently, exceptional MA properties can be achieved within the temperature range from 298 to 473 K. Furthermore, by carefully controlling the structural parameters in RGO metacomposites, both the resonant frequency and effective absorption bandwidth (EAB) can be optimized based on precise manipulation of equivalent electromagnetic parameters. This study not only provides an effective approach for the rational design of MA performance but also offers novel insights into achieving super metamaterials with outstanding performance across a wide temperature spectrum.

Key words: Microwave absorbing materials, Metacomposites, Equivalent electromagnetic parameters, Structural parameters, Wide temperature spectrum