Smart Terahertz Graphene Antenna: Operation as an Omnidirectional Dipole and as a Reconfigurable Directive Antenna

A graphene antenna with dynamical control of radiation pattern is proposed in this article. The device consists of a dipole with two coplanar graphene parasites. Working in the frequency range of 1.94-2.13 THz, the antenna has four radiation operation states that can be selected by setting specific chemical potentials by external electric field on the graphene elements. In state 1, a dipole-like radiation diagram is produced. States 2 and 3 are characterized by specific directional radiation patterns. By selecting the operation state 4, the antenna is switched off. When an SiO
₂
substrate with thickness of 1 μm is considered, chemical potentials are adjusted so that the device operates in the 1.94-2.15-THz range, with negligible changes of its four radiation patterns with respect to the case without substrate.