▎ 摘　　要

Broadband absorbers with multiple absorption bands, adjustable properties and simple configurations in the terahertz region are quite scarce and hold competent aptitude. In this paper, we design and analyze a tunable dual and ultra-broadband metamaterial absorber for terahertz waves based on monolayer continuous structured graphene. With the aid of the variable conductivity of graphene, the designed absorber provides controllable absorption strength and bandwidth. Additionally, the monolayer continuous structure of graphene makes the metamaterial absorber simple in terms of structure and flexible tuning. The two broadband absorption occurs from 0.1-3.1 THz and 6.25-8.55 THz for different graphene chemical potentials, securing a fractional bandwidth of 187.5% and 31%, respectively, for the two bands. Furthermore, the absorber shows great tolerance towards incident angles for both transverse electric and transverse magnetic waves, and is insensitive to the polarization angle. The physical mechanism of the absorber is also analyzed and investigated via field analysis, impedance matching theory and interference theory. Overall, the proposed graphene-enabled metamaterial absorber yields possibilities in various practical applications.