【作者】 牛新建；

【导师】 李宏福；

【作者基本信息】 电子科技大学 ， 物理电子学， 2003， 博士

【摘要】 回旋管是一种重要的新型毫米波器件，具有高峰值功率、高平均功率、高增益、高效率、适当带宽等优点，很适合作毫米波雷达、相控阵雷达、通信及电子对抗、受控热核聚变、工业加工等系统用功率源。作为高能量的微波传输和模式转换部分是回旋管的重要部份，它使回旋管的能量以有效的方式传输和辐射。因此，具有重要的研究价值和应用价值。本论文工作是在“九·五”预研项目， “十·五”预研项目， “十·五”高技术863的资助下，对几种回旋管和高功率微波器件的微波传输和模式转换部分作了全面深入的理论和数值模拟研究，设计加工模式变换器已成功的应用于西北核技术研究所的实验中。本论文的主要工作和贡献在于：1. 研究了过模圆波导轴线弯曲波导和半径微扰变形中的模式耦合问题，并在耦合波理论的基础上，应用“正交函数的展开理论”，将波导内的场展开为电波和磁波“驻波”的级数形式，导出传输线方程组。通过耦合波传输线方程组导出耦合波方程组及相应耦合系数的一般表达式。2. 系统的研究了高功率微波系统中波导各种变形对波传播的影响。详细分析了实现模式转换所需的条件，讨论了不同条件下，数值求解耦合波方程的方法及优化算法。研究、分析计算和讨论了各种数学模型及其计算方法。并对数学模型及计算方法进行了直接或间接地验证。3. 研究了常曲率弯曲和变曲率弯曲模式变换器，编制和发展了“高功率过模波导模式转换结构摸拟”软件。采用不同几何结构和相应的相位重匹配方法，设计出了高效、宽带、紧凑的过模波导模式转换器，并得出了波导半径、频率、弯曲曲率和带宽之间的相互变化关系。以此研制的中心频率8.8GHz，直径的双弯曲TM01—TE11模式变换器已成功的应用于西北核技术研究所的实验中，其设计效率为。研究了TE01—TM11模式变换的两种结构，首次改进了正弦弯曲结构，有效地抑制了寄生模式的输出功率，提高模式转换效率，并可使转换器的长度大为缩短。首次分析了弯曲圆波导TE01—TM11模式转换临界角θc的情况。在临界角情况下，若考虑多模因素，则不能使TE01—TM11的能量发生全转换，而真正的最优化能量全转换角在临界角的附近，且转换的效率与弯波导曲率相关。<WP=8>4. 针对半径渐变微扰波导模式变换器进行了详细的数值模拟和设计。采用相应的相位重匹配技术，可设计出高效、宽带、紧凑的过模波导TE0n—TE01、TM0n—TM01以及采用中间过度模式的TM01—TE11模式转换器。同时为“十·五”军事预研项目设计出高性能TE01—TE11模式转换器。5. 首次详细数值研究了回旋放大器件的新型电子枪端微波输入结构，采用准光模式变换对电子枪阳极进行了优化设计，使电子枪和模式传输与转换的作用融为一体。同时考虑了阳极对电子注的影响。准光模式变换器主要采用矢量绕射理论和几何光学理论，并结合两种理论设计复杂反射曲面。应用分小块的方法，调整入射波束的相位和方向，提高输出波束的质量和准光模式转换的效率。更多还原

【Abstract】 Gyro-devices are new important type of millimeter wave device with the characteristics of high peak power, high average power, high gain, high efficiency and suitability bandwidth and so on. It’s very suit for the power source of millimeter wave high capability radar, phase array radar, millimeter wave communication, electronic counter and other systems. Microwave transmission and mode transformers is important part of gyrotron. The energy of gyrotron can be transmission and radiate with requisite methods. Under this background, supported by the “95 Plan” pre-study item and “15 Plan” pre-study item “863 Plan”, the microwave transmission and mode converter of high power microwave device and gyrotron are studied with complete theory in depth and numerical simulation. The mode converter with design and machining apply in the experiment of institute of northwest nucleus technology successfully. The work and contribute of this paper is the follow:1. Mode coupling with the bent of axis in a circular waveguide and gradual radius changes of the waveguide in overmoded waveguide is studied. On the base of coupling wave theory, outspread theory of perpendicular function is applied to unwrap the waveguide inner field with the series form of electric wave and magnetism wave. The coupling wave equations and currently expression of coupling coefficient is educed.2. The influence of all kinds of distortions of waveguide in high power microwave system is studied, and the realization condition of energy complete conversion is analysis in detail. Optimal arithmetic and the method to solve coupling wave equation with numerical value is discussed in the different condition. The Mathematic models and the numerical simulation methods have been proved out directly or indirect.The optimal analysis of constant curvature and vary curvature overmoded circular waveguide mode converter geometric configuration with the<WP=10>3. different phase rematch and structure is given. The regulation about the radius of the circular waveguide, curvature of bent circular waveguides, frequency and the bandwidth are obtained. The results are contributed to design corresponding circular waveguide mode converter with the tight, the efficient and the wideband.4. The circular waveguide mode conversion with waveguide radius tapered is discussed in detail. It also carries out the optimized analysis about the geometry structure of TE0n-TE11 , TM0n—TM01 mode converter. Adopting different phase rematch techniques, the optimal geometry parameter can be obtained.5. Novel microwave input method of gyrotron amplifier is explored and discussed. Adopting quasi-optical mode converter, the anode of electronic gun and mode conversion is optimal designed. At the same time, the influence of anode to electron beam is taken into account. Quasi-Optical Mode Converter is mainly adopted vector diffraction theory and Geometry optics theory, and the numerical results of complex reflector are analyzed. Phase and direction of the incidence wave is adjusted by each piece of reflector cell.更多还原