Dual-Band Bandpass Filter With Independently Tunable Attenuation Characteristics Using Graphene Nanoplates

A dual-band bandpass filter (BPF) with independently tunable attenuation based on graphene nanoplates is proposed. By utilizing dual coupling paths, the 1.2- and 2-GHz frequency bands realized by the multimode resonant structure can be completely controlled. The graphene nanoplates loaded close to the resonator are responsible for independently tunable attenuation. Meanwhile, the influence of the loaded graphene nanoplates on the original dual-band BPF is analyzed in detail. New branches are added to achieve a stronger coupling of source, load, and passband. Due to good separation of the dual coupling paths and the controllable attenuation of graphene to the signal, a novel dual-band BPF with independently tunable attenuation is obtained. The measured results show that the dual-band BPF achieves independently tunable attenuation of about −4 dB in two passbands with a low reflection of less than −10 dB.