A wideband tunable microwave graphene-based absorber and duplexer

In this paper, a novel tunable graphene-based absorber with more than 90% absorption in the frequency range of 12.8–31.5 GHz and also, duplexer is proposed. This microwave absorber (MA) consists of double split rings and graphene strips placed on a metal-backed dielectric. The characteristic of the graphene surface conductivity is measurable in a wide range of frequencies and it can be manipulated by changing the chemical potential of the graphene; therefore, the proposed MA not only has a wide absorption band but also can be utilized in narrowband applications as well. Then, the performance of the proposed graphene-based MA was further improved. As a result, the absorption bandwidth increased to 33.3 GHz in the frequency range of 10.8–44.1 GHz with an absorption coefficient above 90%. The stable broadband absorption makes the proposed MA attractable for a wide range of applications. © 2022