带状束矩形栅毫米波行波管的研究

为了克服单模近似法(SMA)在分析矩形栅慢波系统高频特性的局限性,用“本征函数法”得到了其色散特性,进而求得耦合阻抗.并针对矩形栅的两种典型结构(浅槽栅和深槽栅)进行数值计算,分析了金属栅的几何尺寸对系统高频特性的影响.设计出3 cm、8mm波段的矩形栅模型,进行实验测量,实验值与理论值符合良好.导出了考虑电子注时的“热”色散方程,得到其小信号增益,讨论了电子注参数和慢波电路几何尺寸对小信号增益的影响,为矩形栅慢波系统行波管的设计提供了理论基础.

STUDY ON mm-WAVE RECTANGULAR GRATING TRAVELING WAVE TUBE WITH SHEET-BEAM

In order to overcome the limit of single-mode approximation(SMA),the dispersion relation was obtained by eigen-function method.The coupling impedance was subsequently derived from the relevant equations.A lot of numerical computations and analysis were done for two typical structures of rectangular waveguide grating: the shallow grating and the deep grating.And the effects of the geometrical dimensions of the grating on high frequency characteristics of system were analyzed.Rectangular gratings models at 3cm band and 8mm band were designed and measured,The experimental values match theoretical values very well.According to linear theory,the "hot" dispersion equations were deduced,and the small-signal gain was achieved.The influences of the radius and current of the electron beam,the acceleration voltage and the geometrical dimensions of the slow-wave structure on the small signal gain were discussed.The results presented in this study provide theoretical basis on designing the rectangular grating traveling wave tube.