摘要
提出了一款基于超材料的太赫兹幅度调制器,其结构由开口"弓"形超材料结构、高电子迁移率晶体管、斜十字馈线和碳化硅衬底四部分构成。"弓"形超材料结构开口处的连通和断开两种状态将对通过该结构的太赫兹波产生不同的响应。在开口处添加高电子迁移率晶体管可模拟开口连通和断开的效果。当对晶体管上的栅极不施加偏压时,超材料结构开口相当于导通,对太赫兹波透射系数高;当对晶体管上的栅极施加偏压时,超材料结构开口相当于断开,对太赫兹波透射系数低。仿真结果表明,在0.22THz处,对晶体管栅极不施加偏压时,调制器的透射系数为0.579;对晶体管栅极施加偏压时,调制器的透射系数为0.040。通过公式计算得到其调制深度为93%,而且对x和y极化入射波具有不敏感的特性。同时,通过分析0.22THz处的电场分布和表面电流分布研究了该太赫兹调制器的工作原理。所设计的太赫兹调制器具有调制深度高、结构简单和易于加工等特点,在太赫兹通信领域具有广阔的应用前景。
A metamaterial-based terahertz amplitude modulator is proposed with the structure co nsisting of an open"bow"shaped metamaterial structure,a high electron mobility transist or,an oblique cross feeder and a silicon carbide substrate.Whether the openings of the"bow"sh aped metamaterial structure are connected or disconnected will produce different responsesto the terahertz waves passing throug h the structure.The effect of connecting and disconnec ting the openings can be simulated byadding high electron mobility transistors to the openingsof the"bow"shaped metamaterial structure.When no bias voltagei sapplied to the gate of the transistor,the opening of the metamaterial structure is equivalent to conduction,and the transmission coefficient to terahertz wavesi s high;when bias voltagei s applied to the gate on the transistor,the opening of the metamaterial structure is equivalent to disconnection,and the transmission coefficient of terahertz waves is low.The simulation results show that the transmission coefficient of the modulator is 0.579 at 0.22 THz when no bias is applied to the transistor gate,while it is 0.040 at 0.22 THz when bias is applied to the transistor gate.The modulation depth of 93%is obtained by the equation,and the modulator is insensitive to x-and y-polarized incident waves.Meanwhile,the operating principle of this terahertz modulator is studied by analyzing the electric field distribution and surface current distribution at 0.22 THz.The terahertz modulator designed in this paper is characterized by high modulation depth,simple structure and easy processing,which has a broad application prospect in the field of terahertz communication.
作者
潘武
杨龙亮
马勇
刘博文
肖惠云
PAN Wu;YANG Longliang;MA Yong;LIU Bowen;XIAO Huiyun(College of Photoelectronic Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,CHN)
出处
《半导体光电》
CAS
北大核心
2021年第5期610-614,共5页
Semiconductor Optoelectronics
关键词
太赫兹
高电子迁移率晶体管
超材料
调制器
terahertz
high electron mobility transistor
metamaterial
modulator