Simulation-Guided Design of Gradient Multilayer Microwave Absorber with Tailored Absorption Performance

Abstract

Flexible microwave absorber (MAR), vital in advanced applications such as wearable electronics and precision devices, are highly valued for their lightweight, exceptional electromagnetic waves (EWs), and ease of fabrication. However, optimizing the electromagnetic parameters of microwave absorption materials (MAMs) to enhance absorption ability and expand effective absorption broadband (EAB, reflection loss (RL) <−10 dB) is a considerable challenge. Herein, a permittivity-attenuation evaluation diagram (PAED) is constructed using parameter scanning based on the Materials Genome Initiative to determine the ideal electromagnetic parameters and thickness, optimize absorption efficiency, and obtain highly efficient absorbers. Guided by the PAED, a multilayer MAR consisting of a “matching-absorption-reflection layer” and a dielectric loss gradient aligned with the direction of EWs propagation is developed. This design significantly enhances the EWs penetration and ensures effective absorption, attributed to the well-matched impedance and attenuation characteristics. As anticipated, the microwave absorption of the absorber (density = 0.063 g cm⁻³) is optimized, with an RL of −34 dB at d = 4 mm and an EAB covering the entire X-band (8.2–12.4 GHz). This study presents a novel approach for establishing a material database for MAMs and developing high-performance absorbers characterized by thinness, lightness, broad operational frequency range, and robust absorption capacity.