Design and Measurement of a Novel Overmoded TE<sub>01</sub> Mode Converter for a Rectangular Gyro-TWT

Chaoxuan Lu; Wei Jiang; Zewei Wu; Guo Liu; Jianxun Wang; Youlei Pu; Yong Luo

doi:10.3390/mi13071111

Micromachines (Jul 2022)

Design and Measurement of a Novel Overmoded TE<sub>01</sub> Mode Converter for a Rectangular Gyro-TWT

Chaoxuan Lu,
Wei Jiang,
Zewei Wu,
Guo Liu,
Jianxun Wang,
Youlei Pu,
Yong Luo

Affiliations

Chaoxuan Lu: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Wei Jiang: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Zewei Wu: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Guo Liu: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Jianxun Wang: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Youlei Pu: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Yong Luo: School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China

DOI: https://doi.org/10.3390/mi13071111
Journal volume & issue: Vol. 13, no. 7
p. 1111

Abstract

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The rectangular gyrotron traveling wave tube (gyro-TWT) with a large aspect ratio (α) has the potential to achieve megawatt-class output power. As an essential component of gyro-TWT, a novel overmoded Ka-band mode converter with an α of 6.19 is designed, analyzed, and cold tested in this paper. Based on the magnetic dipole moment theory, the rectangular overmoded TE01 mode is excited via the rectangular fundamental TE10 mode. The cutoff waveguide is applied to prevent electromagnetic wave transport to the magnetron injection gun (MIG) region and also guarantee higher power electron beam transportation. Simulations predict an operation bandwidth higher than 4 GHz and greater than 99.8% mode purity between 33–37 GHz. To verify this design, the mode converter is manufactured and cold tested. The back-to-back measurement results exhibit a good agreement with the simulation. With similar topologies, the rectangular overmoded TE01 mode can be excited in a different α.

Published in Micromachines

ISSN: 2072-666X (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Mechanical engineering and machinery
Website: https://www.mdpi.com/journal/micromachines

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