Research And Design Of Terahertz Antenna Based On Graphene Materials

As one of the key technologies for 6G,terahertz spectrum resources are abundant,with advantages such as high transmission rate,large transmission capacity,good stability,and strong confidentiality,making it more suitable for explosive data communication.Graphene,as a new material,is widely used in various tunable devices due to its excellent thermal conductivity,carrier mobility,and electrically controllable characteristics.This paper introduces graphene material into the traditional antenna model and studies its effect on the performance of terahertz antennas under different dielectric constant substrates.Multiple antennas designed for the terahertz frequency band with characteristics such as multiple frequency bands and reconfigurability.The main research content and innovation points of this paper are divided into three parts:1.To study the influence of different dielectric constant substrates on the performance of graphene antennas,this paper designs a rectangular microstrip antenna working in the terahertz frequency band.The substrate materials studied are polyimide,quartz,silicon,silica,silicon nitride,and boron nitride,with dielectric constants of 3.5,3.75,3.11,3.9,9.5,and 4.6,respectively.According to the simulation results,the antennas made of quartz and silica materials have superior performance indicators such as return loss(S11),voltage standing wave ratio(VSWR),gain,etc.,which are closer to the design requirements and can provide a basis for substrate selection in subsequent antenna designs.2.To address issues such as the large size and limited operating frequency range of terahertz antennas,this paper designs a multi-frequency antenna that operates in the terahertz frequency band with seven well-performing radiation bands.The antenna adopts a three-layer structure that combines the annular and microstrip antennas,and improves and optimizes the graphene patches using the slot method and the branch method to achieve a seven-band working range from 0.5THz to 3.5THz.The antenna substrate is made of quartz,the ground plane is made of highly conductive copper,and the radiation patch is made of 10nm-thick graphene material.The overall size of the antenna is 80 × 80 ×103.The resonant frequencies of the antenna are 0.52THz,1.32THz,1.63THz,1.93THz,2.5THz,3.07THz,and 3.35THz,and the voltage standing wave ratio at each resonant frequency point is close to 1.3.To address the issues of single-frequency mode and limited operating frequency range of terahertz antennas,this paper designs a frequency-reconfigurable antenna that operates in the terahertz frequency band.Four sets of graphene patches are placed in specific slots,and the conductivity of the graphene patches can be controlled by bias voltage.The two control methods employed in this study both achieved frequency tuning function for the antenna in the terahertz frequency band:In the switch-controlled method,four sets of graphene patches are controlled separately to realize the switching of each set,and the simulation results show that the frequency span of the antenna is 1.17THz.In the overall adjustment method,the four sets of graphene patches are regarded as a whole and gradually fine-tuned,and the simulation results show that the antenna can achieve frequency reconstruction function from 2.60THz to 3.67THz.The reflection coefficient of the antenna under both control methods is less than-15dB,and the relative bandwidth is greater than 10%,with good radiation performance.