▎ 摘　　要

A design of absorber using two-dimensional (2-D) periodic arrays of double-square split loops and resistive strips printed on grounded dielectric substrate is investigated in this letter. Unlike the traditional structure, graphene sheets are proposed for thin absorbing structures at microwave frequencies. The analysis of absorption properties is based on the dynamic model of graphene, which takes into account the surface impedance of graphene layer. Both narrowband and broadband tunable absorbers can be demonstrated with the same structure by tuning the conductivity of graphene. Furthermore, the equivalent circuit method (ECM) is used to introduce the working principles of the proposed absorber. In addition, the absorber shows relatively stable performance with different oblique incidence angles.