Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus.
Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, Roorkee, India.
Sci Rep. 2022 Dec 22;12(1):22145. doi: 10.1038/s41598-022-26398-2.
In terahertz (THz) wireless systems, graphene shows a tremendous promise for the implementation of miniaturized and reconfigurable antennas due to its unique tunable property. This paper presents a wideband beam reconfigurable directional antenna for THz wireless communication systems. The antenna design concept is based on the Yagi-Uda antenna working principle. The proposed antenna consists of a centre-fed graphene-based driven dipole and three graphene-based parasitic elements on either side of the driven element. These graphene-based parasitic elements either act as directors or reflectors by controlling the surface conductivity of these elements. The surface conductivity of the elements is adjusted individually by applying a bias voltage via the chemical potential of the graphene. The main beam direction of the antenna can be reconfigured by controlling the chemical potentials of the graphene-based parasitic elements. Specifically, the proposed graphene THz antenna reconfigures the main beam into four orthogonal directions (0°, 90°, 180° and 270°) at an operational frequency 1.25 THz. The antenna achieves a directional symmetrical radiation pattern with 14 dBi gain and a front-to-back ratio of 15.5 dB. Furthermore, the proposed graphene THz antenna provides a stable reflection coefficient in four reconfigurable cases and an ultra-wideband of 10-dB impedance bandwidth of 120%. Therefore, this novel design technique of graphene-based ultra-wideband high gain beam reconfigurable THz antenna is promising for THz wireless systems.
在太赫兹（THz）无线系统中，由于其独特的可调谐特性，石墨烯在实现小型化和可重构天线方面显示出巨大的应用前景。本文提出了一种用于太赫兹无线通信系统的宽带波束可重构定向天线。该天线的设计理念基于八木天线的工作原理。所提出的天线由中心馈电的基于石墨烯的驱动偶极子和驱动元件两侧的三个基于石墨烯的寄生元件组成。这些基于石墨烯的寄生元件通过控制这些元件的表面电导率，作为定向器或反射器发挥作用。通过通过石墨烯的化学势施加偏置电压，可以单独调节元件的表面电导率。通过控制基于石墨烯的寄生元件的化学势，可以重新配置天线的主波束方向。具体来说，所提出的石墨烯太赫兹天线在工作频率为 1.25 THz 时将主波束重新配置为四个正交方向（0°、90°、180°和 270°）。天线在 14 dBi 增益下实现了具有 15.5 dB 前后比的定向对称辐射模式。此外，所提出的石墨烯太赫兹天线在四个可重构情况下提供了稳定的反射系数和超宽的 10-dB 阻抗带宽为 120%。因此，这种基于石墨烯的超宽带高增益波束可重构太赫兹天线的新颖设计技术有望应用于太赫兹无线系统。
