▎ 摘　　要

In this paper, we propose a graphene nanoribbon-ring cross structure. A multi-band absorber is obtained by a simple combination of graphene nanoribbons and and graphene ring. We obtain that the theoretical absorption of three resonance wavelengths are 99.8%, 98.4% and 65.7%, respectively. We carefully analyzed each resonance wavelength, and the compact structure makes that small changes in the position of graphene nanoribbons and graphene ring have a great influence on the number of resonance wavelength. Meanwhile, the small changes in the chemical potential of graphene can tune the position of resonance wavelengths in the spectrum. At last, we discuss the sensing properties of this structure. The FoM ( figure of merit) values of the three resonance wavelengths are high, and the FoM of the three peaks can reach 4.1, 3.679 and 12.66. The absorbers have great adjustability and great application potential in sensing.