W波段带状注速调管准光输出结构改进设计

Improved design of quasi-optical output coupler for a W-band multicavity sheet beam klystron

本文使用等效偶极子理论和相位叠加原理对准光输出结构进行了理论分析,并在此基础上对准光渐变输出结构进行了一系列的改进设计,通过对冷腔特性包括特性阻抗、耦合系数、有载Q值、模式分布均匀性等方面的详细研究,发现抛物线渐变准光输出腔相比于直线渐变、三角形渐变和切比雪夫渐变结构具有更好的冷场性质,对改善带状注速调放大器的互作用效率和工作带宽有一定的优势.在此设计基础上加工了5间隙直线渐变结构准光输出耦合器.

An intensive research have been done about the W-band sheet beam klystron （WSBK） for its potential value in active denial system application. The output cavity has an important influence on the output power, efficiency, bandwidth and spectrum. In this paper, multiple types of quasi-optical （QO） output couplers are designed based on the theory of equivalent dipoles and phase superimposition, and detailed study on the cold characteristics such as R/Q, M, loaded Q and mode uniformity has been all demonstrated. Compared with other tapers, QO output coupler with parabolic taper shows more excellent performance than the linear, triangle and Chebyshev tapers. We will receive benefit from improving the beam-wave efficiency and bandwidth of WSBK. Besides, a QO-output coupler with linear taper for initial experiment is fabricated.