A synergistic design model for ultrathin broadband microwave absorbers using electromagnetic frequency dispersion coefficients

Ultrathin, broadband microwave absorbing materials (MAMs) are crucial for weight-sensitive and space-constrained applications. This study introduces the electromagnetic frequency dispersion coefficient (EFDC), a synergistic dielectric-magnetic parameter that moves beyond conventional complex mechanisms. Our model directly links EFDC to microwave absorption (MA) performance, guiding the design of advanced MAMs. By optimizing EFDC, we achieved an ultra-wide effective absorption bandwidth (EAB) of 7.04 GHz at 1 mm and 9.28 GHz at 1.3 mm. Moreover, the temperature invariance of EFDC ensures consistent MA performance from 298 K to 473 K, despite the differing thermal responses of permittivity and permeability. This principle outlines a systematic design strategy for fabricating ultrathin and broadband MAMs, establishing a robust framework for developing high-attenuation absorbers suitable for complex frequency and thermal environments. The authors introduce the Electromagnetic Frequency Dispersion Coefficient (EFDC), a unified parameter linking material properties to microwave absorption. It enables ultra-thin, broadband absorption with record performance and stable operation across temperatures, simplifying the design of advanced absorbing materials.