摘要
由于过模Ka波段高功率微波返波管通常输出TM_(0n)混合模式,在保证较高能量转换效率的条件下,难以同时兼顾其输出模式的纯度,而辐射终端为达到理想发射效果则要求单一模式馈入,这就给输出混合模式微波源的实际应用带来困难。针对这一技术难点,提出了一种结构紧凑的TM_(0n)-TEM(n≤5)混合模式转换器的设计方法,利用内外两路同轴阶梯波导并配合适当的插板调相结构可以实现在高功率容量条件下,较宽频带范围内,高效地将TM_(0n)混合模式转换为单一的TEM模,降低了此类高频段HPM源模式纯化设计的难度。
Overmoded Ka-band high power microwave(HPM)sources with high energy efficiency can not ensure the output modes purity,which are generally mixed TM_(0n) modes.However,it is necessary for high radiation efficiency that the microwave input to the ready-made radiation terminal is a certain single mode.So it is hard to put these HPM sources into application.In this paper,a hybrid modes converter,utilizing outer and inner coaxial waveguides to purify TM_(0n) mixed modes with high power handing capacity,is proposed.With this method,the TM_(0n)(n≤5)mixed modes can be converted into pure TEM mode with high conversion efficiency,reducing the modes purification difficulty in the design of the overmoded HPM sources.
引文
[1]Fan Yuwei,Yuan Chengwei,Zhong Huihuang,et al.Experimental investigation of an improved MILO[J].IEEE Trans Plasma Sci,2007,35(4):1075-1080.
[2]Zhang Jun,Jin Zhenxin,Yang Jianhua,et al.Recent advance in long-pulse HPM sources with repetitive operation in S-,C-,and X-bands[J].IEEE Trans Plasma Sci,2011,39(6):1438-1445.
[3]Zhang Xiaoping,Zhong Huihuang,Shu Ting,et al.Theoretical design and experimental studies of C-band MILO[J].High Power Laser and Particle Beams,2005,17(8):1129-1132.
[4]Zhang Hua,Shu Ting,Ju Jinchuan,et al.Gigawatt-class radiation of TM01mode from a Ku-band overmoded Cerenkov-type high-power microwave generator[J].IEEE Trans Plasma Sci,2014,42(6):1567-1572.
[5]彭升人,袁成卫,舒挺,等.Ku波段高功率TM0n-TM01混合模式转换器设计[J].国防科学技术大学学报,2015,37(2):36-39.(Peng Shengren,Yuan Chengwei,Shu Ting,et al.Design of Ku-band high power TM0n-TM01hybrid convertor.Journal of National University of Defense Technology,2015,37(2):36-39)
[6]Wu Dapeng,Shu Ting,Zhu Jun,et al.Mode composition analysis on experimental results of a gigawatt-class Ka-band overmoded Cerenkov oscillator[J].Phys Plasmas,2014,21:073105.
[7]Yuan Chengwei,Liu Qingxiang,Zhong Huihuang,et al.A novel TEM-TE11mode converter[J].IEEE Microw Wirel Compon Lett,2005,15(8):513-515.
[8]Peng Shengren,Yuan Chengwei,Shu Ting.Analysis of a high power microwave radial line slot antenna[J].Rev Sci Instrum,2013,84:074701.
[9]Yuan Chengwei,Zhong Huihuang,Liu Qingxiang,et al.A novel TM01-TE11circularly polarized mode converter[J].IEEE Microw Wirel Compon Lett,2006,16(8):455-457.
[10]Xiao Renzhen,Chen Changhua,Song Wei,et al.A high-power high-efficiency klystronlike relativistic backward wave oscillator with a dual-cavity extractor[J].Appl Phys Lett,2011,98:101502.
[11]白珍,李国林,张军.X波段高功率微波选模定向耦合器[J].强激光与粒子束,2013,25(7):1747-1750.(Bai Zhen,Li Guolin,Zhang Jun.X-band high power microwave mode-selective directional coupler.High Power Laser and Particle Beams,2013,25(7):1747-1750)
[12]孙钧,胡咏梅,张立刚,等.圆波导定向耦合器在高功率微波测量中的应用[J].强激光与粒子束,2014,26:063040.(Sun Jun,Hu Yongmei,Zhang Ligang,et al.Application of circular waveguide couplers in high power microwave measurement.High Power Laser and Particle Beams,2014,26:063040)