▎ 摘　　要

A broadband graphene-based tunable terahertz metamaterial absorber is achieved by constructing a two-layer graphene microstructures, and detailed numerical and theoretical analysis of the absorber are carried out. We have investigated the relationship between the absorption performance and the geometric parameters of the graphene microstructure layers, as well as the incident angles. The optimum absorption is above 90% in a broad frequency range of 0.65-1.3 THz (bandwidth 0.65 THz). The bandwidth of the absorber can be tuned by changing the voltage biasing of the graphene Fermi energy. In addition, a transmission line method has been used to analyze and calculate the intrinsic mechanism of the absorber. The designed absorber could find potential applications in terahertz imaging and communication systems.