W波段多注交错双栅行波放大器的高频特性

High frequency characteristics for W-band multiple beam staggered double-vane traveling wave tube amplifier

提出了一种采用平面线性排列的3个圆形电子注代替平面带状电子注的W波段交错双栅行波放大器微型化慢波高频结构，并重点对其行波传输特性和输入输出耦合特性进行了仿真设计和参数优化．结果表明，这种平面微型化高频结构的行波传输色散特性良好且有很大的工作带宽，所产生的强轴向电场分布非常有利于电子注与高频场的能量交换和相互作用．在保证平面微型结构中圆形注通道直径和带状注通道高度相同的情况下，得到的耦合阻抗是带状注交错双栅慢波高频系统2～3倍，为行波放大器高效率的注波互作用和高功率输出提供了新的研究思路．为了与该交错双栅高频系统相匹配，提出了一种更为简单易行的输入与输出耦合结构，仅采用三周期渐变过渡段就可以实现反射系数s11在较宽频带内低于-20dB的良好结果，更有利于行波放大器未来的工程实现与应用．

A new micro-structure scheme was proposed by using three parallel pencil beams instead of the sheet beam for the W-band staggered double vane traveling wave tube amplifier, and detailed analysis and op- timization were given for the high frequency characteristic with its input/output couplers. The results show that the structures have a good dispersion characteristic and very broad working bandwidth, the strong component of longitudinal electric field is very benefit to the interaction and exchange of the energy between the electron beam and the high frequency field. Keep the diameter of the pencil beam tunnel as the same of the height of the sheet beam tunnel, the interaction impedance of the structures can achieve 2 - 3 times as high as the sheet beam scheme to obtain the high interaction efficiency and high output power. In order to match the staggered double-vane high frequency system, we present a more simple and easy input/output coupler structure. Just using three periods of transition structures, the input/output structures of the traveling wave tube amplifier can achieve a low reflection loss below the - 20 dB in a broad bandwidth with more suitable application in the devices later.