基于PIN二极管的可开关宽带极化转换超表面  

Switchable Broadband Polarization Conversion Metasurface Based on PIN Diodes

作　　者：李达民 王佳云 苏晓强 董丽娟[2] 陈新伟[1] 张文梅[1] 杨荣草[1] Li Damin;Wang Jiayun;Su Xiaoqiang;Dong Lijuan;Chen Xinwei;Zhang Wenmei;Yang Rongcao(School of Physics&Electronic EngineeNng,Shanxi University,Taiyuan,Shanxi 030006,China;Shanxi Province Key Laboratory of Microstructure Electromagnetic Functional Materials,Shanxi Datong University,Datong,Shanxi 037009,China)

机构地区：[1]山西大学物理电子工程学院,山西太原030006 [2]山西大同大学微结构电磁功能材料省市共建山西省重点实验室,山西大同037009

出　　处：《中国激光》2022年第3期28-36,共9页Chinese Journal of Lasers

基　　金：山西省科技创新团队项目(201805D131006);山西省重点研发计划项目(201903D121026);山西省研究生教育创新项目(2020SY001)。

摘　　要：为了在宽频内实现可开关的高效率线极化转换,设计了一个嵌入PIN二极管的十字架型极化转换超表面。仿真结果显示,当PIN二极管处于导通状态时,在4.03~7.71 GHz范围内,该超表面的极化转换率超过90%,相对带宽为62.7%;当PIN二极管处于截止状态时,该超表面在工作频段相当于反射板。通过理论分析和表面电流分布解释了极化转换机理。最后,对所制作样品的实验测量进一步证实了该超表面可开关的极化转换效果。所设计的超表面有望应用于电磁兼容和极化探测等领域。Objective Since the artificial metasurface was proposed,it has attracted extensive attention owing to its unique physical properties and wide applications in many fields,such as holographic imaging,microstrip antenna,absorber,and polarization converter.The polarization converter is an important research topic in the application of metasurfaces.Currently,single-band,multiband,and broadband polarization conversion metasurfaces have been developed,and their operating frequency bands cover the micro wave,terahertz,infrared,and visible bands.However,most of the traditional polarization converters lack switchable performance.Although the frequency or amplitude values of some metasurfaces are tunable,the methods are complex.Herein,a switchable and high-efficiency broadband polarization conversion metasurface is designed with PIN diodes.By controlling the state of the diodes,the switchable polarization conversion is realized,and the measured and simulation results agree excellently,which verifies the switchable polarization conversion of the metasurface.Compared with the traditional polarization conversion metasurface,the proposed structure may be applied in practical engineering to meet special requirements.The design enriches the research of metasurfaces and provides a strategy for switchable polarization converters.Methods In the simulation,electromagnetic(EM)simulation software,CST,based on the finite integration technique(FIT),was adopted to simulate the proposed polarization conversion metasurface.Periodic boundary conditions(unit cell)were set along the x and y directions,the EM wave propagated along the negative z-axis,and the electric and magnetic fields were polarized along the y and x axes,respectively.The polarization conversion rate(PCR)is defined as R_(PCR)=|r_(xy)|^(2)/(|r_(xy)|^(2)+|r_(yy)|^(2))where r_(yy)and r_(xy)are the co-polarization and cross-polarization reflection coefficients,respectively.In the experimental measurement,a 25 x 25 unit structure sample was built by adopting printed circuit board(

关 键 词：材料 超表面 可开关极化转换 PIN二极管 宽带 

分 类 号：O441[理学—电磁学]