Mixed-Modes Conversion Method for Dual-Mode Relativistic Backward-Wave Oscillators

• Published in: IEEE microwave and wireless components letters 2021-11, Vol.31 (11), p.1243-1246
• Main Authors: Gui, Youyou, Xiao, Renzhen, Li, Jiawei, Shao, Hao, Shi, Yanchao, Zhang, Yuchuan, Song, Zhimin, Wang, Huida, Bai, Xianchen, Sun, Jun
• Format: Article
• Language: English
• Subjects: Bandwidth; Converters; Dual-mode relativistic backward-wave oscillator (RBWO); high-power microwave (HPM); Microwave oscillators; Microwave theory and techniques; mixed-modes converter; Oscillators; Pulse duration; Relativistic effects; Structural engineering; Transmission line matrix methods; Waveguides; Wireless communication
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2021.3112625

In this letter, a dual-cavity TM 01 and TM 02 mixed modes to TM 01 mode converter is proposed for a dual-mode relativistic backward-wave oscillator (RBWO) application. This converter is more compact than the conventional converters and the TM 02 mode is cutoff in the output waveguide, which forces the purity of the output TM 01 mode to 100%. Especially, the converter is adjustable, and by simply replacing the waveguides in it, the converter can be well-matched to different proportional mixed modes. Electromagnetic simulation results show that the conversion efficiency of the converter is higher than 99%. The converter is validated in the high-power microwave (HPM) generation experiment of the dual-mode RBWO and a conversion efficiency of 98% is realized. A pure TM 01 microwave with power of 4.6 GW and pulse duration of 42 ns at 10 GHz was obtained.