Graphene-based High-frequency Millimeter-wave Tunable Broadband Absorber

Abstract To address the issues of narrow absorption bandwidth and low absorption rate in current high-frequency millimeter-wave absorbers, this paper proposes a graphene-based metamaterial broadband absorber. The absorber consists of a PET layer at the bottom, an ITO layer, a SiO2 layer, a surface graphene layer, and a patterned copper structure. Simulation results indicate that the proposed absorber achieves an absorption bandwidth of 101.3 GHz, with an absorption frequency range of 117.5 to 218.8 GHz, where the absorption rate exceeds 90%. Near-perfect absorption is achieved at 170 GHz, covering the high-frequency millimeter-wave band. By adjusting the Fermi level of graphene, tunable absorption can be achieved, and the absorber is insensitive to both TE and TM polarization. The proposed absorber features good symmetry, compact size, tunability, and excellent insensitivity to TE and TM waves. This design holds promise for enhancing communication security and reducing electromagnetic interference in sixth-generation (6G) devices.