Graphene-based THz absorber: adjustability via multiple gate biasing

A multi-layer absorber using multi-bias arrays of graphene is proposed. The design methodology using the equivalent circuit model and matching concept is described. A heavy optimization process is performed to optimize bias values for different functionality. Leveraging, increased control parameters due to multi-bias scheme and simple circuit model representation, two operational modes are achieved as wide-band and multi-band absorption. The proposed absorber can perfectly absorb THz incident waves between [Formula: see text] in wide-band mode while shows perfect absorption response in [Formula: see text] and [Formula: see text] in multi-band operational mode. Besides, response dependency to layers thicknesses, electron relaxation time, chemical potentials, and incident angle are reported to express acceptable sensitivity of the device. Such a reconfigurable absorber is in demand for several applications, ranging from medical imaging to indoor communication.