在传统的场匹配理论的基础上建立起盒型窗的通用传输参数矩阵, 并提出了一种新型的混合模式传输方法来扩展盒型窗带宽．在研究结果的基础上, 通过理论分析和数值计算得到了能满足Q波段超宽带带状束行波管所需求的新型混合模式传输盒型窗的初始结构和尺寸、利用三维高频分析软件HFSS优化并得到了最终结构参数．通过仿真验证和热分析, 证明了新的混合模式紧凑型盒型窗在34~52GHz频带内平均功率容量达到10kW、反射系数小于-18dB、相对带宽超过40%．冷测实验结果证实了盒型窗在要求带宽内反射系数均小于-18dB, 能满足实际器件的指标要求

Based on field-matching theory, the general transmission matrix of pill-box windows and a new concept of hybrid transmission modes pill-box window were presented to extend the bandwidth of output window. With guidance of the new concept, the primitive structure and parameters of the extremely broad bandwidth pill-box output window, working over 34~52GHz, had been obtained. Afterward, HFSS was employed to optimize the parameters of the window and to examine the optimized mode. Through amount of thermodynamic analysis and optimization design, the extremely broad bandwidth pill-box window, with average power capacity 10kW over 40% bandwidth whose insert loss is less than －18dB, was attained. The cold test verifies the results of the design.