圆波导TM_(01)模式转换器中TE_(11)和TE_(21)模式对圆波导耦合器耦合度的影响  

Effect of the TE_(11) and TE_(21) Modes in the Circular Waveguide TM_(01) Mode Converter on the Coupling Degree of the Circular Waveguide Coupler

作　　者：陈家辉 周振宇 翁明[1] 曹猛[1] CHEN Jiahui;ZHOU Zhenyu;WENG Ming;CAO Meng(Faculty of Electronic and Information Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电子与信息学部,西安710049

出　　处：《真空科学与技术学报》2024年第6期492-502,共11页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目(61971342)。

摘　　要：为了准确地测量出圆波导耦合器的耦合度,文章研究了圆波导TM_(01)模式转换器中TE_(11)和TE_(21)模式对耦合度的影响。依据圆波导中TM_(01)、TE_(11)和TE_(21)模式场分布的特点,用CST仿真研究了TE_(11)或TE_(21)模式的含量对耦合度分散性的影响。采用仿真和实验测量,对测量过程中两个模式转换器之间的相对角度对耦合器中出现的模式以及耦合度分散性的影响进行了研究。结果表明,随着耦合器中TE_(11)或TE_(21)模式含量的增加,耦合度的分散性也随之增加;用矩形TE10转圆波导TM_(01)模式转换器测量耦合度时分散性较大,并且当两个模式转换器之间的相对角度为0°或180°时,耦合器中会出现少量的TE_(21)模式,而相对角度为90°或270°时耦合器中会出现少量的TE_(11)模式;用同轴TEM转圆波导TM_(01)模式转换器测量耦合度时,耦合器中几乎不含有TE_(11)模式和TE_(21)模式,且耦合度的分散性较小;对比两种不同类型的圆波导TM_(01)模式转换器在耦合度测量中的仿真与实验结果,文章认为采用平均耦合度可以较好地消除耦合度分散性,更能反映耦合器的真实耦合度。该研究工作为准确标定耦合器耦合度提供了新的测试方法与依据。In order to accurately measure the coupling degree of the circular waveguide coupler,the influence of TE_(11) and TE_(21) modes on the coupling degree of the circular waveguide TM_(01) mode converter is studied in this paper.According to the characteristics of TM_(01),TE_(11) and TE_(21) mode field distribution in a circular waveguide,the influence of TE_(11) or TE_(21) mode content on coupling degree dispersion is studied by CST simulation.The influence of the relative angle between two mode converters on the mode in the coupler and the coupling degree dispersion is studied by simulation and experimental measurement.The results show that the dispersion of coupling degree increases with the increase of TE_(11) or TE_(21) mode content in couplers.When the coupling degree is measured with a rectangular TE10 to circular waveguide TM_(01) mode converter,the dispersion is large,and a small amount of TE_(21) mode will appear in the coupler when the relative angle between the two mode converters is 0ºor 180º,while a small amount of TE_(11) mode will appear in the coupler when the relative angle is 90ºor 270º.When the coupling degree is measured by the coaxial TEM to circular waveguide TM_(01) mode converter,there is almost no TE_(11) mode and TE_(21) mode in the coupler,and the coupling degree is less dispersed.Comparing the simulation and experiment results of two different types of circular waveguide TM_(01) mode converters in coupling degree measurement,it is concluded that using the average coupling degree can better eliminate the coupling degree dispersion and reflect the real coupling degree of couplers.The research provides a new test method and basis for accurately calibrating the coupling degree of couplers.

关 键 词：耦合器 模式转换器 圆波导 平均耦合度 

分 类 号：TN98[电子电信—信息与通信工程] TM931[电气工程—电力电子与电力传动]