Design of quasi-optical mode converter for dual-frequency gyrotron
-
摘要:
回旋管一般使用准光模式变换器实现高阶腔体模式到高斯波束的转换。结合标量衍射理论、KS迭代算法、几何光学、最小均方法等方法设计了工作频率为140 GHz（TE24, 9）和105 GHz（TE18, 7）的双频准光模式变换器。仿真结果显示所设计的准光模式变换器工作频率为140 GHz（TE24, 9）时能量传输效率99.0%、高斯含量99.7%，工作频率为105 GHz（TE18, 7）时能量传输效率97.3%、高斯含量98.0%。能够满足MW级双频回旋管的应用需求。
Abstract:Quasi-optical mode converters are usually used in gyrotrons to realize the conversion of high-order cavity mode to Gaussian beam. Using the scalar diffraction theory, the K-S phase-correcting optimization iterative algorithm Geometrical Optics and the least mean square(LMS) algorithm, this paper designs a dual-frequency quasi-optical mode converter with operating frequency of 105 GHz (TE18,7) and 140 GHz (TE24,9). According to the simulations results, the conversion efficiencies are 97.3% at 105 GHz and 99.0% at 140 GHz. And the Gaussian contents of the output beam on the window surface are 98.0% at 105 GHz and 99.7% at 140 GHz. This high efficiency dual-frequency quasi-optical mode converter can be used in a MW dual-frequency gyrotron.
-
Key words:
- quasi-optical /
- gyrotron /
- mode converter /
- Gaussian beams /
- dual-frequency
-
图 2 105 GHz TE18,7和140 GHz TE24,9双频辐射器的内壁上的场分布图（dB值）。辐射器边缘和口径已在图中标出
Figure 2. Field distribution on the wall of the launcher for 105 GHz TE18,7 and 140 GHz TE24,9 gyrotron (in dB), the edges of the launcher aperture and cut are indicated
图 3 105 GHz TE18,7和140 GHz TE24,9双频辐射器的内壁微扰分布图
Figure 3. Profile of the wall surface of the dual-frequency launcher for 105 GHz TE18,7 and 140 GHz TE24,9 gyrotron
图 4 与辐射器同坐标系，半径为5 cm圆柱面上的电场分布图（dB值）
Figure 4. E-field distribution on a cylinder with radius of 5 cm in the same coordinate system as the launcher(in dB)
图 6 仿真软件中得到的xz平面上的电场分布图（dB值）
Figure 6. Side view of the E-field of the whole system along the center symmetry xz plane obtained from simulation（in dB）
图 7 窗平面处的电场等值线图。每条线间隔3 dB
Figure 7. Contour plots of the E-field on the window plane. The contours are in 3 dB increments
表 1 两种模式在圆波导中的传播参数
Table 1. Propagation parameters of the circular waveguide for considered modes
mode frequency/GHz waveguide radius/mm caustic radius/mm pitch distance/mm axial bounce angle/（°） TE18,7 105 21.5 8.76 41.1 73.1 TE24,9 140 21.5 8.80 42.6 72.4 
下载: 导出CSV
表 2 仿真结果
Table 2. Results of simulation
mode frequency/GHz Gaussian content/% conversion efficiency/% z-offset/mm y-offset/mm TE18,7 105 98.0 97.3 2.00 2.25 TE24,9 140 99.7 99.0 0.50 0.50
下载: 导出CSV
-
[1] Gregory S N, Manfred K T, Michael I A P. The gyrotron at 50: Historical overview[J]. Journal of Infrared Millimeter & Terahertz Waves, 2014, 35(4): 325-381. [2] Drumm O, Dammertz G, Thumm M. Design methods for mirrors in a quasi-optical mode converter for a frequency step-tunable gyrotron[C]//Infrared and Millimeter wave. 2002: 191-192. [3] Jin J, Thumm M, Piosczyk B, et al. Novel numerical method for the analysis and synthesis of the fields in highly oversized waveguide mode converters[J]. IEEE Trans Microw Theory Tech, 2009, 57(7): 1661-1668. doi: 10.1109/TMTT.2009.2021878 [4] Hirata Y, Mitsunaka Y, Hayashi K, et al. The design of a tapered dimple-type mode converter/launcher for high-power gyrotrons[J]. IEEE Trans Plasma Science, 2003, 1(31): 142-146. [5] Rock B, Neilson J M, Vernon R J. A power-optimizing integrated design of a dual-frequency gyrotron quasi-optical mode converter[J]. IEEE Trans Plasma Science, 2012, 40(6): 1522-1529. doi: 10.1109/TPS.2012.2192296 [6] Agapova M, Belov Y, Chirkov A, et al. Megawatt power dual-frequency gyrotrons for modern fusion facilities[C]//2019 44th International Conference on Infrared, Millimeter, and Terahertz waves. 2019: 627-628. [7] Jin J, Gantenbein G, Jelonnek J, et al. Quasi-optical mode converter for 1MW dual-frequency gyrotrons[C]//2017 Eighteenth International Vacuum Electronics Conference. 2017. [8] Jin J, Gantenbein G, Ruess T, et al. Design of a quasi-optical mode converter for a dual-frequency coaxial-cavity gyrotron[C]//2019 44th International Conference on Infrared, Millimeter, and Terahertz waves(IRMMW-THz). 2019. [9] Prinz O, Gantenbein G, Thumm M. Advanced quasi-optical mode converter for a multi-frequency gyrotron[C]//2008 IEEE International Vacuum Electronics Conference. 2008: 64-66. [10] Ikeda R, Oda Y, Kobayashi T, et al. Development of multi-frequency gyrotron for ITER and DEMO at QST[C]//2016 41st International Conference on Infrared, Millimeter, and Terahertz waves(IRMMW-THz). 2016. [11] Liao Shaolin. Multi-frequency beam-shaping mirror system design for high-power gyrotrons: Theory, algorithms and methods[D]. Madison: University of Wisconsin at Madison, 2008: 155-166. [12] 施美友, 屈劲, 薛长江, 等. 95GHz回旋管内置准光模式转换器仿真设计[J]. 强激光与粒子束, 2011, 23(9):172-176. (Shi Meiyou, Qu Jin, Xue Changjiang, et al. Simulation design of quasi-optical mode converter for 95 GHz gyrotron[J]. High Power Laser and Particle Beams, 2011, 23(9): 172-176 [13] 王斌, 刘云龙, 王虎, 等. 高阶不对称体模回旋管Denisov型准光模式变换器[J]. 强激光与粒子束, 2016, 28:073005. (Wang Bin, Liu Yunlong, Wang Hu, et al. Denisov-type quasi-optical mode converter for higher-order asymmetric volume mode gyrotron[J]. High Power Laser and Particle Beams, 2016, 28: 073005 doi: 10.11884/HPLPB201628.073005 [14] 刘健卫. 准光模式变换器研究与设计[D]. 成都: 电子科技大学, 2014: 19-20.Liu Jianwei. Research and design of quasi-optical mode converter[D]. Chengdu: University of Electronic Science and Technology of China, 2014: 19-20 [15] 李浩, 汪海洋, 李天明, 等. W波段TE62-TEM00准光模式变换器[J]. 强激光与粒子束, 2011, 23(11):278-282. (Li Hao, Wang Haiyang, Li Tianming, et al. W-band quasi-optical TE62-TEM00 mode converter[J]. High Power Laser and Particle Beams, 2011, 23(11): 278-282 [16] 边慧琦, 杜朝海, 潘石, 等. 太赫兹多模式宽带准光模式变换器的设计分析[C]//2018年全国微波毫米波会议. 2018: 1419-1412.Bian Huiqi, Du Chaohai, Pan Shi, et al. Design and analysis of terahertz multimode broadband quasi-optical mode converter[C]//2018 National Microwave and Millimeter Wave Conference. 2018: 1419-1412. [17] Du Chaohai, Pan Shi, Liu Pukun. THz broadband quasi-optical mode converter antenna system[C]//2016 IEEE international conference on microwave and millimeter wave technology(ICMMT). 2016. [18] 乔益民. 220 GHz边廊模准光模式变换器的研究[D]. 成都: 电子科技大学, 2013: 41-43.Qiao Yimin. Study of a quasi-optical mode converter for 220 GHz whispering-gallery mode[D]. Chengdu: University of Electronic Science and Technology of China, 2013: 41-43 [19] Prinz O, Gantenbein G, Liu Yinghui, et al. Highly efficient quasi-optical mode converter for a multifrequency high-power gyrotron[J]. IEEE Trans Electron Devices, 2009, 56(5): 828-934. doi: 10.1109/TED.2009.2015819 [20] Bogdashov A A, Denisov G G. Synthesis of the sequence of phase correctors forming the desired field[J]. Radio Physics & Quantum Electronics, 2004, 47(12): 966-973. [21] Vlasov S N. Transformation of a whispering gallery mode, propagating in a circular waveguide, into a beam of waves[J]. Radiofizika, 1972, 15(4): 14-17. [22] Vlasov S N, Orlova I M. Quasioptical transformer which transforms the waves in a waveguide having a circular cross section into a highly directional wave beam[J]. Radiophysics and Quantum Electronics, 1974, 17(1): 115-119. doi: 10.1007/BF01037072 [23] Denisov G G, Kuftin A N, Malygin V I, et al. 110 GHz gyrotron with a built-in high-efficiency converter[J]. International Journal of Electronics, 1992, 72(5): 1079-1091. -
点击查看大图
计量
- 文章访问数: 1631
- HTML全文浏览量: 447
- PDF下载量: 47
- 被引次数: 0
