Research And Design Of Terahertz Reflectarray Based On Graphene

Compared with the microwave and millimeter-wave frequency bands,the terahertz band has unique performance and has now deeply affected various fields such as communications,radar,electromagnetic weapons,electronic warfare,safety inspection,non-destructive testing,medical imaging,astronomy and the like.Due to the rapid development of terahertz wireless systems,researchers are paying more and more attention to terahertz antenna research.In recent years,advances in the field of terahertz antennas have been well-established,from the miniaturization of traditional antennas to the advent of new material antennas.In the terahertz band,due to the excellent conductivity of graphene materials,its application is more advantageous than metal.In this dissertation,We investigate the characteristics of antenna based on graphene.The detailed work indudes:1.A brief introduction of the research progress on terabertz antenna and graphene-based terahertz antenna was given.The basic knowledge of antenna,conductivity model of graphene and how to establish graphene antenna model in HFSS are introduced.2.Design of four different substrates of graphene antenna unit,in addition to the antenna processing and external bias voltage feeder system structure design.The method of two kinds of applied bias voltage(plus the bottom gate voltage and the top gate voltage)is proposed.The simulation shows that the graphene has the electrical control characteristic in the terahertz frequency band,that is,the conductivity of the graphene can change from its bias voltage the conductor state becomes non-conductor.According to the technical requirements of the proposed antenna design and processing program.3.The simulation results show that the directivity of the reflectarray can be adjusted by changing the phase difference between the adjacent cells by changing the external bias voltage of the graphene antenna element,and achieving the beam scanning.The gain of the reflectarray can reach 15 dBi.And through the theoretical analysis,it can be concluded that the simulated beam scanning angle is consistent with the theoretical analysis.