First Demonstration and Performance of <i>X</i>-Band High-Power Magnetron With Parallel Cathodes
Jiayang Liu, Hao Zha, Jiaru Shi, Jiaqi Qiu, Jian Gao, Yi Wen, Chuanxiang Tang, Huaibi Chen
Abstract
This article presents an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${X}$ </tex-math></inline-formula> -band high-power magnetron with two parallel cathodes. The phase locking was achieved within the proposed magnetron by two coupled coaxial cavities working at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> -like mode. The eigenmode, frequency-domain, and particle-in-cell (PIC) simulations have been conducted to analyze the characteristics of the proposed magnetron. A magnetron prototype has been designed, fabricated, and tested in Tsinghua University. The total weight of the magnetron together with the permanent magnet system and the asymmetric 3-dB hybrid used to combine the output power was approximately 27 kg. The cold measurements showed good agreement with the frequency-domain simulations. In the high-power experiment, a maximum combined power of 3.43 MW with the duty cycle of 0.54 ‰ was obtained at the working frequency of approximately 9.289 GHz. The combining efficiency and the total efficiency were greater than 99% and 53%, respectively. This is the first experimental demonstration of the internal phase locking of the magnetrons with parallel cathodes.