基于旋转对称腔提取结构的同轴相对论磁控管研究

In order to develop a high power microwave (HPM) source which has the advantages including compact and miniaturized structure, high output power and power conversion efficiency, low-order and controllable output mode and so on, a coaxial relativistic magnetron (RM) with rotational-symmetric-cavity extraction (RSCE) structure proposed in this project is systematically and thoroughly investigated in the aspects of theory, simulation and experiment. The main innovation points are listed as follows. (1) By the method of electromagnetic field analysis, the necessary conditions for generating coaxial TEM mode, linearly polarized TEn1 modes and circularly polarized TEn1 modes in a coaxial RM with RSCE structure are derived. And it provides the theory foundation for many aspects, such as designing a compact RM in a low frequency band, outputting HPM with high output power and power conversion efficiency in an RM with an odd number of resonant cavities, outputting HPM with any given single mode in the conditions of various structural forms and operating modes of an RM, and so on. (2) Based on the Hull cut-off condition and B-H start-oscillation condition, the value ranges of resonant-cavity structure parameters of an RM are derived. And it provides a new method for fast designing the resonant-cavity structure of an RM. (3) An S-band coaxial RM with RSCE structure is fabricated, and is aimed at realizing single mode output of 2 GW level with the coaxial TEM mode or TE11 mode, corresponding to the power conversion efficiency of 30% or more. For these reasons, the research of this project has important significance for meeting the application requirements of HPM.

为研制一种同时具有紧凑化小型化、高功率高效率、输出模式低阶可控等特点的高功率微波源，本项目提出一种基于旋转对称腔提取结构的同轴相对论磁控管，并分别从理论、模拟和实验方面对其开展系统深入研究。主要创新点如下：利用电磁场分析法推导基于旋转对称腔提取结构的同轴相对论磁控管产生同轴TEM模式、线极化TEn1模式以及圆极化TEn1模式的必要条件，为该类相对论磁控管能在低频段下实现紧凑化设计，在奇数谐振腔结构下实现高功率高效率输出，在多种结构形式和工作模式下实现任意给定模式的单模输出等方面提供理论基础；利用Hull截止条件和B-H起振条件推导谐振腔结构的参数取值条件，为谐振腔结构参数的快速设计提供一种新的方法；研制出一台S波段基于旋转对称腔提取结构的同轴相对论磁控管，重点实现功率转换效率大于30%的2GW级同轴TEM模式或同轴TE11模式的单模输出。本项目研究对于满足高功率微波的应用需求具有重要意义。

为研制一种同时具有紧凑化小型化、高功率高效率、输出模式低阶可控等特点的高功率微波源，本项目提出一种基于旋转对称腔提取结构的同轴相对论磁控管（RM），并分别从理论、模拟和实验方面对其开展系统深入研究。.（1）利用电磁场分析法推导基于旋转对称腔提取结构的同轴相对论磁控管产生同轴TEM模式、线极化TEn1模式以及圆极化TEn1模式的必要条件，为该类相对论磁控管能在低频段下实现紧凑化设计，在奇数谐振腔结构下实现高功率高效率输出，在多种结构形式和工作模式下实现任意给定模式的单模输出等方面提供理论基础；利用Hull截止条件和B-H起振条件推导谐振腔结构的参数取值条件，为谐振腔结构参数的快速设计提供一种新的方法。.（2）对基于旋转对称腔提取结构的同轴RM开展了模拟研究。在电压670 kV，电流9.09 kA，磁场0.2 T条件下，输出微波频率2.50 GHz，输出功率3.27 GW，效率53.7%，输出模式TEM模。在电压770 kV，电流9.03 kA，磁场0.2 T条件下，输出微波频率2.35 GHz，输出功率3.86 GW，效率55.5%，输出模式同轴右旋圆极化TE11模。.（3）对基于旋转对称腔提取结构的同轴RM开展了实验研究。在电压约682 kV，电脉宽约57 ns，二极管电流约8.81 kA，外加磁场 0.21 T条件下，输出微波频率2.45 GHz，微波脉宽32ns，输出微波功率2.01 GW，功率效率33.5%，输出模式TEM模。.（4）应用前景举例。利用本项目提出的基于旋转对称腔提取结构的同轴RM可以产生圆极化TE11模式，并且可通过改变磁场通电电流切换轴向磁场的正负方向，进而可以在ms量级时间内实现圆极化TE11模式极化方向的在线切换。