Broadband configurable perfect absorber based on surface patterned graphene sheet in THz region

Abstract

In this study, a novel wideband metamaterial absorber is proposed, and its underlying operational mechanism is thoroughly analyzed. The suggested structure consists of a highly conductive gold substrate, Rogers RT5880LZ as the middle-insulated dielectric, and a circular enclosure with a square-shaped graphene layer, from bottom to top, respectively. The perks of our work are that this absorber is configurable and contains solely a simple-designed graphene layer, offering the benefits of simple implementation, affordability, and frequency tunability. Additionally, graphene is a tunable metamaterial; the results demonstrate that the recommended absorber can be used in wide-band applications without requiring geometrical reconfiguration, and due to external DC bias voltage, which adjusts graphene conductivity. First, the circular-shaped absorber is provided. Then by adding ribbon to our preliminary design, the absorption bandwidth grows to approximately 2 THz. Our design is symmetrical; this feature affects polarization sensitivity. The presented absorber demonstrates strong potential for filtering applications, communication and information security, imaging, and sensing material characterization applications.