Design of Ultra-wideband Amplitude-adjustable Electromagnetic Absorber

In this work, an ultra-wideband amplitude-adjustable electromagnetic absorber for intelligent electromagnetic cloaking has been designed by utilizing the graphene sandwich structure whose surface impedance can be regulated by applying bias voltage. The proposed absorber consists of a complete graphene film for impedance modulation, two layers of graphene films with different patterns, flexible substrates, lightweight foam, and a ground layer. Compared with the traditional electromagnetic absorbers, this absorber not only has a wider bandwidth, but also has the ability of modulation, demonstrating great application value in the field of broadband adaptive stealth. The simulation results show that the absorber can achieve −10 dB wave absorption within 2.5–13 GHz and has ±5 dB continuous tunable range when modulating the impedance of the top graphene film.