同轴横电磁波转圆波导横磁波01模式的转换器研究  

Research of Mode Converter from Coaxial Transverse Electromagnetic Wave to Circular Waveguide TM_(01)

作　　者：周振宇 陈家辉 翁明 林舒[1,2] 曹猛[1,2] ZHOU Zhenyu;CHEN Jiahui;WENG Ming;LIN Shu;CAO Meng(Key Laboratory of Physical Electronics and Devices,Ministry of Education,Xi’an Jiaotong University,Xi’an 710049,China;Faculty of Electronic and Information Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电子物理与器件教育部重点实验室,西安710049 [2]西安交通大学电子与信息学部,西安710049

出　　处：《西安交通大学学报》2023年第11期171-180,205,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(61971342)。

摘　　要：为了对高功率微波(HPM)在线测量系统中的核心器件耦合器进行准确标定,采用锥形渐变加圆柱的内导体结构,设计了一种S波段同轴TEM模式转圆波导TM_(01)模式的模式转换器。从模式耦合和阻抗匹配的基本思路出发,对模式转换过程、工作带宽的扩展以及非TM_(01)模式的抑制等方面进行了理论分析。使用CST仿真软件对模式转换器的结构参数进行了优化,对模式转换器的反射性能、传输性能、工作带宽、输出模式和脉冲响应进行了实验测量。仿真和实验结果均表明:所设计的模式转换器中几乎不含有TE_(11)和TM_(01)模式以上的高次模式,TM_(01)模式纯度较高;在工作频点2.1 GHz处的反射系数小于-30 dB,传输系数大于-0.2 dB,实测模式转换效率可以达到96%以上,工作带宽为74 MHz,而且脉冲响应时间很短。该模式转换器目前已成功应用于S波段在线耦合器的标定之中。该研究为HPM在线测量过程中模式转换器的设计提供了新思路。To ensure accurate calibration of the core device coupler in the high power microwave(HPM)online measurement system,this study presents the design of an S band coaxial TEM to circular waveguide TM_(01) mode converter.The converter incorporates a tapered gradient and cylindrical inner conductor structure.Starting from the basic ideas of mode coupling and impedance matching,theoretical analysis was conducted to explore mode conversion,operating bandwidth expansion,and suppression of non-TM_(01) modes.The structural parameters of the mode converter were optimized using CST simulation software.Experimental measurements were carried out to assess reflection performance,transmission performance,working bandwidth,output mode,and pulse response of the mode converter.Both simulation and experimental results indicate that the mode converter contains almost non-TE_(11) mode and higher-order modes beyond TM_(01),highlighting a relatively high purity of TM_(01) mode.At the operating frequency point of 2.1 GHz,the reflection coefficient is less than-30 dB,and the transmission coefficient is more than-0.2 dB.The measured mode conversion efficiency exceeds 96%,the operating bandwidth is 74 MHz,and the pulse response time is very short.The mode converter has been successfully applied to the calibration of the S band online coupler,offering a new approach for mode converter design in the HPM online measurement processes.

关 键 词：模式转换器 同轴线 圆波导 锥形渐变线 耦合波理论 模式测量 

分 类 号：TN98[电子电信—信息与通信工程]