Development of a high-power millimeter vacuum electron device using the connection of a backward wave oscillator and a traveling wave tube

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04617
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Kanazawa University
• Principal Investigator: Soga Yukihiro 金沢大学, 数物科学系, 助教 (90525148)
• Co-Investigator(Kenkyū-buntansha): 佐藤 政行 金沢大学, 数物科学系, 教授 (00266925)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 後進波発振管 / 電子ビーム / THz波

Outline of Final Research Achievements

With the goal of achieving high power in terahertz electron tubes, backward wave oscillators (BWO) with staggered double-grating slow-wave structures were developed for the K-band (18-26 GHz) and Ka-band (26-40 GHz) frequencies. In the K-band, a maximum output of 26 W and an average output of 17 W were achieved at a frequency of 24.2 GHz. In the Ka-band, a maximum output of 9.2 W and an average output of 7.3 W were observed at 37 GHz.
Based on the results obtained from the K-band and Ka-band, assuming that the output follows the square-law dependence on frequency, the estimated average output at 1 THz is 10 mW. This is approximately three times higher than the currently available practical devices. These results demonstrate that the staggered double-grating slow-wave structure is a promising candidate for high-power terahertz electron tubes.

Free Research Field

プラズマ物理

Academic Significance and Societal Importance of the Research Achievements

現在、高出力・高周波・小型で周波数可変の定常発振が可能なテラヘルツ光源は存在しない。そのため、その新規開発が求められている。本研究では、2枚のグレーティングを半周期ずらして配置したスタッガード・ダブルグレーティングを遅波回路とする後進波発振管が、テラヘルツ光源として有望であることを実験的に検証した。この研究がさらに進展し、テラヘルツ帯での高出力化が達成されれば、テラヘルツ科学の進展に大いに寄与することが期待される。