Broadening Electromagnetic Absorption Bandwidth: Design from Microscopic Dielectric-Magnetic Coupled Absorbers to Macroscopic Patterns

Abstract

As electromagnetic absorption materials with broadband absorption are highly pursued in the recent development of cutting-edge electronic and telecommunication industries, the traditional uniform bulk composites with dielectric and magnetic active absorbers are attracting extensive interest, with remaining concerns of extending the effective absorption bandwidth. To understand the impact of using dielectric-magnetic coupled absorption fillers and to implement artificial absorption structures in the absorption performance, in this work, both nanoscale nonmagnetic and magnetic graphene hybrid fillers are prepared as the effective absorbers. In the comparison based on the microscopic studies, magnetic graphene fillers are found to possess dual absorption bands in the investigation region, which is responsible for extending the effective absorption bandwidth. With subsequent macroscopic structure design based on the as-fabricated composites, the artificial structures established on the composites embedded with magnetic graphene fillers exhibit more broadened absorption bandwidth because of the exclusive advantages of absorption from multiple thickness and greater interfacial impedance matching. The results suggest that combination of developing microscopic dielectric-magnetic coupled absorbers and macroscopic structure design will fundamentally extend the effective absorption bandwidth of the electromagnetic absorption materials.