任意曲线槽波导色散和损耗特性的高次有限元分析

本文用高次有限元法分析了任意形状槽波导的色散和损耗特性。该方法的有效性和可靠性由实验和其它计算结果所证实。文中对诸如如矩形，三角形，抛物，椭圆和余弦等形状的槽波导进行了系统的研究。计算结果表明，不同形状槽波导具有相近的色散特性，但损耗相差很大，其中Ｖ形槽波导损耗最小，大约是矩形槽波导的一半。文中给出的曲线可供设计槽波导元件和电路时参考。     

曲折矩形槽波导慢波系统的高频特性

对曲折矩形槽波导新型慢波系统的高频特性进行了研究，通过理论分析和数值计算，得到了它的色散曲线和耦合阻抗，并分析了结构参数变化时对色散特性和耦合阻抗的影响。曲折矩形槽波导结合了曲折波导散热能力强、色散特性好、容易加工和矩形槽波导单模工作、低损耗、大尺寸等优点，因此这种新型的慢波系统有可能在毫米波及亚毫米波段的行波管中具有较好的发展前景。     

螺旋槽波导特性的计算与模拟研究

计算了螺旋槽波导的色散特性和群速度,用“准周期边界条件”方法和谐振法模拟计算了螺旋槽波导的色散特性,两种方法的模拟结果与计算都比较一致。此外,还模拟测试了渐变与规则螺旋槽波导连接的匹配性能、螺旋槽波导高频系统的传输特性。结果表明,螺旋槽波导是非常适用于回旋行波管的高频结构。     

矩形槽波导的模式图

本文用有限元法分析了矩形槽波导。对矩形波导的计算验证了我们的有限元程序是有效的。文中给出的矩形槽波导模式图有助于设计基于矩形槽波导的短毫米波和亚毫米波器件。     

任意槽形矩形慢波结构高频特性分析

矩形慢波结构及其变态具有易于微加工、横向尺寸大、散热好等优点,是一种有潜力工作于毫米波段或亚毫米波段的高频系统.文中利用场匹配的方法推导出了任意槽形状开放式矩形波导慢波结构的统一色散方程,并利用数值计算方法分析了几种特殊槽形状加载慢波结构的色散特性及耦合阻抗,得到三角形结构色散和耦合阻抗均最弱,而倒梯形结构色散最强,耦合阻抗最大.     

槽波导色散特性的模匹配法分析

槽波导是一种很有前途的毫米波传输结构。本文用模匹配法分析了单槽波导和非对称双漕波导的色散特性,给出了n阶近似的色散方程的一般公式,据此编制了求解单槽波导和非对称双槽波导色散特性的通用程序,利用该程序对若干单槽和非对称双槽波导色散特性进行了计算,并与已有的数据进行了比较,获得了十分一致的结果,从而证实了所给公式和程序的正确性和可靠性。     

用有限元法分析任意截面槽波导

用有限元法分析了任意形状槽波导。在槽波导开放端口引进了吸收边界条件。对矩形槽波导、Ｖ形槽波导、圆形槽波导的分析表明，计算结果与实验值以及其它方法得到的结果有较好的吻合。     

电子注通道形貌对折叠波导慢波结构的影响

折叠波导结构是一种极具潜力的太赫兹行波管慢波电路.分析了电子注通道形貌对折叠波导高频特性的影响,包括色散特性、耦合阻抗和衰减特性.仿真结果表明,相比于圆形电子注通道,矩形电子注通道的折叠波导结构色散要略微陡一些,损耗也要略微高一些.在中心频率处,矩形电子注通道结构的耦合阻抗比圆形电子注通道结构低0.5Ω左右.皮尔斯小信号理论表明,在中心频率处,矩形电子注通道结构和圆形电子注通道结构的增益速率分别为4.85 dB/cm和5.22 dB/cm,具有相似的3 dB带宽,约为6.3 GHz和7.2 GHz.粒子模拟表明,对于矩形和圆形电子注通道,54 mm(100个周期)的折叠波导慢波结构在220 GHz增益分别为24.42 dB和28.44 dB.     

曲折波导慢波电路的特性

矩形曲折波导具有机械强度高，容易加工，热性能好以及工作频带宽等优点。文中对曲折波导的色散特性和互作用阻抗进行了计算。并指出，将曲折波导应用于毫米波行波管作为其慢波电路，可解决大功率、宽频率和难加工的问题。     

部分介质填充槽波导色散特性的网络分析

本文给出了部分介质填充单槽和非对称双槽波导的横向等效网络。以此为基础,用微波网络方法分析了各种槽波导的色散特性,并将所得到的数据与用其它方法得到的结果进行比较,两者吻合好。证实本方法在保持有高的计算精度的情况下极大地简化了分析和求解过程。文中通过对宽带槽波导定向耦合器的具体设计,证明了本方法在槽波导电路分析和设计中的重要实际意义。     

Finite-element analysis of dispersion and loss characteristics of groove guide with arbitrary shapes

The dispersion and loss characteristics of groove guide with arbitrary shapes are analyzed with high-order finite element method. The effectiveness and the reliablity of the method are verified by the experiments and the results obtained by other methods. Groove guides with various groove shapes, such as rectangular, triangular, parabolic, elliptic and cosine functions, are investigated systematically. The calculating results show that the dispersion of groove guide with different groove shape is almost the same, however, the loss characteristics is rather different; among them, V-shape groove guide has the lowest loss which is about half of the rectangular one. All the curves and the data given in this paper can be used in designing elements and circuits of the groove guide.     

Analysis of Loss and Dispersion Characteristics for Groove Guides with Arbitrary Groove Profiles by an Equivalent Active Transmission Line Method*

Loss and dispersion characteristics of groove guide are two practically important factors in the design for millimeter wave system consisting of groove guide. In this paper, a new method is presented for analyzing loss and dispersion characteristics of the groove guides with arbitrary groove cross-sections. The method is based on the combination of an equivalent active transmission line equation and the staircase approximation. Numerical results of dispersion and attenuation properties for some groove guides with different groove profiles are given. The effectiveness and practicality of the present analysis are confirmed by the data given in the literature.     

Dominant mode characteristics of circular groove guide

Circular groove guide is a kind of waveguide for millimeter waves with low loss, large dimensions, and low dispersion. In this paper, the dominant mode characteristics of it is analysed. The technique that mode macthing method combines with point matching method is used to derive the Nth-order characteristic equation of the guide. The 1st order, 2nd order and 3rd order approximate curves that the normalized cutoff wavelength of circular groove guide varies with c/a are given. The attenuation curves are given at 1mm, 1.5mm and 3mm wavelength. The numerical results are in well agreement with the experimental results published.     

ANALYSIS OF ARBITRARILY TRAPEZOIDAL-GROOVE GUIDE WITH THE CONFORMAL MAPPING METHOD

The arbitrarily open trapezoidal-groove guide is analyzed with the conformal mapping technique. A new formula is given for the evaluation of one fundamental parameter associated with the technique. The relationship between the cut-off wavelength for the dominant mode and the geometry of the guide structure is studied; dispersion characteristic of the groove guide is also given. Some numerical results are shown to be in good agreement with both experimental data and the results of the finite element method (FEM). Moreover, it is testified that dispersion of the trapezoidal-groove guide is low. The obtained results are significant for the design and application of the open trapezoidal-groove guide for millimeter waves.     

圆形槽波导的􀀂 FDTD 分析

圆形槽波导^[1]是一种新型的宽频带、大功率，低损耗和大尺寸波导结构，在毫米波、亚毫米波波段有重要应用前景。利用时域有限差分法（FDTD）分析了圆形皮导的传输特性，计算了圆形槽波导工作在主模TE^[1]11情况下的色散曲线和截止频率，并与已知的理论值相比较，两者一致性好。     

Transmission characteristics of several kinds of closed groove waveguides for millimeter waves

An advantage of closed groove guide over open groove guide is attended. In this paper, the several kinds of closed groove guides including the trapezoidal-, elliptic- and parabolic-groove guides as new types of millimeter wave transmission lines are presented. Their dispersion and cut-off characteristics of the dominant mode are analysed and compared with ones of the closed V-and circular- groove guides by using the equivalent network method. The obtained results have important meaning in theoretical studies and actual applications of groove waveguides.     

Characteristics of Arbitrarily-Shaped Helical Groove Slow-Wave Structure Loaded with a Concentric Dielectric-Rod

The dielectric-rod is loaded on the central axis of the arbitrarily-shaped helical groove slow-wave structure. Meanwhile, the profile of the groove is replaced by a series of continuous rectangular steps. The unified dispersion equation of the arbitrarily-shaped helical groove waveguide loaded with a concentric dielectric-rod is obtained by means of a combination of filed-matching method and admittance-matching technique. Then, the effect of the change of groove shape and the dielectric-rod parameters on the dispersion and coupling impedance is approached by theory calculation. The results show that: loaded with dielectric-rod, the bandwidth of the helical groove traveling wave tube (TWT) is effectively broadened, but the coupling impedance is reduced. Among the five different groove shapes, the triangle-type groove has the widest bandwidth but the smallest coupling impedance, and the swallow-tailed-type groove has the narrowest bandwidth but the largest coupling impedance.     

圆形槽波导振荡器的分析与设计

圆形槽波导是一种新型的毫米波传输线，具有低损耗、低色散、宽频带、大尺寸和大功率容量等优点．利用圆形槽波导来制作振荡器是圆形槽波导实用化道路上的一大进步。本文用FDTD方法来计算振荡器结构尺寸的变化对外电路阻抗的影响，从而寻找最佳匹配尺寸，设计了3mm波段圆形槽波导振荡器，并给出了实验结果。     

An Active Transmission Line Solution for Loss Characteristics of the Groove Guide

The analysis of loss characteristics for groove guide is one of the most practically important problems in millimeter wave system consisting of groove guide. In this paper, the calculation of the skin loss for the modes in the groove guide is ended to the solution of an active equivalent transmission line equation. The effectiveness and the reliability of the present method are verified by comparison between the present results and those given in the literature.     

On the Main Mode of Trapezoidal-Groove Guide By Finite Element Method

In this paper, the propagation properties such as the dispersion characteristics, cut-off wavelength, guide wavelength and field distribution for the main mode of trapezoidal-groove guide are analysed by using the finite element method. The dispersion is very low, and the field distribution in a trapezoidal-groove guide is similar to that of rectangular one. The results have important values in design, manufacture, and application of groove guides.