▎ 摘　　要

A tunable ultra-wideband metamaterial absorber based on graphene is presented herein. Its absorption exceeds 90% from 1.57 to 8.46 GHz when the Fermi level of the graphene is 0.7 eV, and it can be tuned by changing the bias voltage applied on the graphene. To explore the mechanism of its wideband absorption and tunability, the surface current of the metamaterial absorber at given absorption frequency is monitored for different Fermi levels. Further simulation results indicate that the absorption by the metamaterial absorber is insensitive to the polarization state of the incident wave but sensitive to its angle of incidence. The absorber offers the advantages of simplicity, ultra-wideband operation, and tunable absorption, having potential applications in the fields of electromagnetic stealth technology, detectors, and communication.