Design and circuit analysis approach of graphene-based compact metamaterial-absorber for terahertz range applications

This research paper attempts the characterize and design analysis for the graphene-based compact tunable metamaterial absorber in the regime of terahertz region. The absorber consists of SiO₂ substrate, single layer of graphene and Au layer as the bottom plane. The design demonstrates the wide-band of operation 2.37–3.45 THz produce dual-band absorption by optimizing the dimensions with parametric analysis. Over the broad-band absorption the designed structure reaches over the 90% (2.37–3.45) THz with relative bandwidth absorption of 37.11% and absorption peaks at frequencies 2.91 THz and 5.61 THz are 99.98% and 95.48%. Using the method of Nicolson–Ross–Weir (NRW) constitutive EM parameters and effective impedance of metamaterial absorber calculated and validate the rate of absorption. For the Transverse Electric waves (TE) the proposed design structure is polarization-insensitive with an angle upto 90°. The geometrical structure of the current one acquired through the gradual development which provide behaviour of polarization insensitive, making the designed structure practically realizable. Accordingly, the metamaterial designed absorber find the potential application in the THz region are sensing, detection, imaging and spectroscopy.