Multiscale Design of Dielectric Composites for Enhanced Microwave Absorption Performance at Elevated Temperatures

Abstract Aerospace vehicles and electronic devices are often operated in elevated temperature environments, which has led to an increased demand for high‐temperature microwave absorbing materials (MAMs). The microwave absorption properties of MAMs are influenced not only by the intrinsic material characteristics but also by the micro‐, meso‐, and macro‐structural configurations of the composites. This paper reviews recent advancements in high‐temperature MAMs through a multiscale design approach. Due to the temperature sensitivity of permittivity, MAMs tend to exhibit microwave reflection behavior at elevated temperatures. Strategies aimed at regulating conductivity and polarization behavior can enhance impedance matching under these conditions; however, this often results in an unavoidable reduction in loss capability. In contrast to traditional design methodologies, MAMs constructed from subwavelength‐scale functional units can achieve remarkable anti‐reflection effects through discrete unit distribution, thereby significantly optimizing both dielectric loss capacity and impedance matching. Furthermore, the equivalent electromagnetic parameters of metacomposites are intrinsically linked to their physical properties and structural attributes. This relationship offers a novel strategy for enhancing high‐temperature microwave absorption performance. It is anticipated that this review will provide insightful guidance for future explorations into innovative and highly efficient high‐temperature MAMs.