Advancing Terahertz Connectivity of Innovative Design of a Directional Cross-Dipole Antenna with Conformal Graphene-Based Reconfigurable Intelligent Surface

In contemporary systems, there is a growing emphasis on harnessing tunable terahertz (THz) waves to advance wireless communication swiftly. Furthermore, reconfigurable intelligent surfaces (RISs) have noticeably enhanced the performance of THz components and devices that enabling them to control electromagnetic waves effectively. Within the domain of wireless systems operating within the THz frequency range, a demand has arisen for adjustable directional antennas. This paper presents a novel approach that suggests a solution involving a customizable directional antenna design which utilizing a cross-dipole configuration with a central graphene-based dipole element. The electrical conductivity of these dipole elements can be adjusted independently by applying a bias voltage via the graphene's chemical potential. The concept of employing a graphene-based Reconfigurable Intelligent Surface (RIS) to actively manipulate Terahertz (THz) waves. By carefully engineering the reflection characteristics of the individual unit cells, the overall system performance can be enhanced. The proposed conformal RIS design comprises a repetitive arrangement of rectangular graphene meta-atoms positioned on a silicon substrate grounded with metal. The paper also provides a model featuring an equivalent circuit for the RIS design and its solution. Furthermore, an implementation of tunable surfaces featuring the conformal graphene-based RIS. It is developed to be placed beneath the cross-dipole antenna at an appropriate distance. This setup enables the control of radiated patterns through a reconfigurable process that involves changing the states of the meta-atoms to achieve specific codes with corresponding patterns. The antenna can achieve various gains that ranging from 8.3 to 9.3 dBi. The results of this study demonstrate the promising potential of the proposed antenna structure for efficient and intelligent THz wireless communications.