摘要
太赫兹波频段介于毫米波和红外光之间,具有诸多优异特性,太赫兹天线更是太赫兹通信、雷达和成像等应用系统中的核心元器件。然而,目前报道的太赫兹天线均无法满足较大动态范围的相位扫描、高效率辐射和大偏转角度的需求。该文设计了3种石墨烯太赫兹天线,最小尺寸为5μm,并对其辐射效率和相位调控特性进行研究,进而提出具有双共振模式的石墨烯-金属太赫兹超表面天线,缓解了传统的基于单共振模式的相位动态调控范围和辐射效率之间的矛盾,实现了0~360°的动态相位调控,且辐射效率高于20%。该研究采用微加工工艺进行样品加工,通过改变栅极电压,在实验上获得了1.03 THz的太赫兹动态相位调控,反射率高于23%,与仿真结果基本吻合。在此基础上,该文基于连续相位编码设计了石墨烯超表面相控阵天线,理论上实现了太赫兹波束在-25°~25°范围内的实时波束偏转。该文为解决超表面相控阵天线的相位动态调控范围小、辐射效率低等难题提供了新的研究思路。
Terahertz wave is the electromagnetic field with frequencies between that of infrared and millimeter waves.It has attracted increasing attention in both fundamental research and technological applications for its unique characteristics.In terahertz telecommunication,radar and imaging systems,terahertz antenna is key for the performance.To date,reported terahertz antennas suffer from limited phase modulation,relatively low efficiency and small beaming angle.Here these challenges are addressed by first designing three types of terahertz graphene antennas with the smallest size of 5μm.Then a novel type of antenna with dual resonances is proposed,and achieve dynamic phase modulation within the full 2πrange and meanwhile high efficiency above 20%.This performance surpasses antennas with single resonance since dual resonances alleviate the contradiction between large phase modulation range and high efficiency.Terahertz graphene antennas are fabricated with standard micro-fabrication processes,and experimentally obtained terahertz dynamic phase modulation of 1.03 THz with reflection efficiency above 23%,which agree basically with simulation results.Making use of the phase modulation metasurfaces tuned according to continuous phase coding,terahertz beam steering is numerically realized with dynamic range of-25°~25°.This work will provide a strategy for achieving large-range phase modulation and beam steering beyond the terahertz regime.
作者
罗小青
黄文礼
王彬旭
李光元
LUO Xiaoqing;HUANG Wenli;WANG Binxu;LI Guangyuan(Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China)
出处
《集成技术》
2023年第4期77-90,共14页
Journal of Integration Technology
基金
深圳市基础研究学科布局项目(JCYJ20180507182444250)
深圳市基础研究面上项目(JCYJ20220531100206014)。
关键词
太赫兹天线
石墨烯超表面
相控阵
相位动态调控
波束扫描
terahertz antenna
graphene metasurface
phased array
dynamic phase modulation
beam steering
