中文摘要：

本文提出一种半径和周期双重扰动的非均匀圆波导TE0n模式变换器.通过耦合波理论（CWT）和数值优化方法对该模式变换器进行研究,计算结果与电磁仿真软件基本一致.与传统的均匀结构半径微扰模式变换器比较,非均匀扰动结构TE0n模式变换器可以在更少的波纹周期内实现高于均匀结构的模式转换效率,95%功率转换绝对带宽增加150%,器件长度减小接近一半.本文的研究工作为设计轴向尺寸短、工作带宽大、转换效率高的高功率回旋管外接模式变换器提供了重要参考.

英文摘要：

In this paper,we present an optimal design of TEOn nonuniform ripple-wall mode converter in circular waveguide.The research work is based on the general coupled wave theory and numerical optimization method.The results of numerical calculation are in good agreement with those of simulation by HFSS.Compared with traditional TEOn mode converter of periodic waveguide perturbations,the TEOn nonuniform ripple-wall mode converter can achieve a high mode conversion efficiency with less corrugated periods.The length of the converter is shortened nearly by a half and the operating bandwidth with over 95%mode conversion is increased by 150%.The research work provides an important theoretical reference and a physics model for designing high power gyrotron mode converter with small axial size,wide operating bandwidth and high conversion efficiency.