Analysis for Transmission Properties of Arbitrarily Trapezoidal-Groove Waveguide for Millimeter Waves

In this paper, the transmission properties such as the dispersion and attenuation characteristics for the dominant mode of the trapezoidal-groove waveguide with arbitrarily inclined angle are analyzed and discussed by using the mode-matching method. Some calculated results are in very good agreement with the published data. The obtained conclusions are of important significance in theoretical studies and actual applications of trapezoidal-groove waveguides for millimeter and submillimeter waves.     

Study on Transmission Characteristics of Trapezoidal-Groove Guide with Mode-Matching Method

In this paper, the dispersion, cut-off and attenuation characteristics of trapezoidal-groove guide are analyzed by using the mode-matching method. The relationships between the guided parameters and variations of relative guide's sizes are discussed in detail. The calculated results are in good agreement with those in relevant reference. So, the obtained conclusions have important values in theoretical studies and actual applications of trapezoidal-groove guides for millimeter and submillimeter waves.     

Transmission Properties of Closed Trapezoidal-Groove Guide for Millimeter Waves

The transmission characteristics of the mode TE₁₁ for a new type of closed trapezoidal-groove guide with arbitrary inclined angle are analysed in detail with the mode-matching method in this paper. The calculated results are in good agreement with the experimental values in the published reference. The dispersion of the closed trapezoidal-groove guide is very low. The relationships of the cut-off wavelength and the attenuation constant with the structural sizes of the closed trapezoidal-groove waveguide are also obtained. The given results have very important value in study, design, manufacture and application for closed trapezoidal-groove waveguide.     

On the Dominant Mode in Closed Trapezoidal-Groove Guide by Finite Element Method

The structure of closed trapezoidal-groove guide is similiar to that of open one, but it can be used to prevent energy from leaking out of the guide. In this paper, the propagation characteristics of dominant mode in closed trapezoidal-groove guide are analysed by using finite element method and the results are discussed.     

Analysis of the Scattering Characteristic of Several Waveguide Components Using Boundary Element Method

Several kinds of waveguide components such as curved waveguide bends, arbitrary angle waveguide bends and T-junctions have been analyzed with boundary element method in this paper. A new discretization method for the boundary element method to solve the waveguide discontinuities has been given. The numerical results obtained agree well with the experimental results and numerical results in other literature. Especially, the scattering characteristics of Forded E-, H-plane T-junctions in 3mm band have been analyzed using boundary element method and the calculation results are presented.     

改进的边界元法及其在波导问题中的应用

本文提出一种改进界元法，它使形成的边界元方程不隐含本征量，避免大阶数矩阵的转置。因此降低了计算机内存要求，提高了求解速度。文中还对几个例子作了计算。     

Impedance Characteristics of Closed Elliptic-Groove Waveguide for Millimeter Waves

A characteristic equation and impedance characteristic for the dominant mode of closed elliptic-groove guide have been analyzed and discussed by using the mode-matching method. The reference size of the closed elliptic-groove guide for the good impedance matching with rectangular guide in actual application is given. The obtained conclusions are of important significance in theoretical studies and actual applications of closed elliptic-groove guide for millimeter waves.     

基于边界元法的微结构光波导模场分布研究

本文基于加权余量法,阐述了利用边界元法求解矢量亥姆霍兹方程的数学基础-亥姆霍兹方程的边界积分方程;并推导了数值求解该边界积分方程的方法;利用推导结果,编写计算机程序分析了圆光波导的模式场分布情况。实验结果表明,该方法可以在较低方程组阶数,较少输入数据量的前提下准确地分析微结构光波导内模式场的分布情况。     

变形矩形脊波导传输特性分析

针对波导器件在使用中可能会产生的变形,采用有限元方法分析了矩形脊波导在错位和受力变形时对其传输特性的影响。数值分析结果表明,错位变形使脊波导截止波长变长,单模带宽增大程度小于1%,对于脊波导传输特性影响较大的是两侧受力变形,当变形达到10%时,其特性变化超过13%以上,在使用中应引起重视。     

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.     

Analysis of the Transmission Characteristics of the Inverted Trapezoidal-Ridge Waveguide

As a new kind of broadband microwave component, transmission characteristics of the dominant TE mode in inverted trapezoidal-ridge waveguide have been analyzed by finite element method. Variations of the cutoff wavelength, single-mode bandwidth, field patterns, characteristic impedance, attenuation constant and power-handling capacity with the varied ridge dimensions have been investigated in details. The longer cutoff wavelength, broader single mode bandwidth and lower characteristic impedance can be achieved for smaller ridge gap. While the lower attenuation and higher power-handling capacity can be realized for larger ridge gap. Numerical results in this paper provide an extension to the existing design data for ridge waveguide and are considered helpful in microwave and millimeter-wave applications.     

Transmission Characteristics with Second Order Approximations of Elliptic-Groove Waveguide

In this paper, the transmission characteristics for the dominant mode H _{e 11} ⁽¹⁾ in the vertical-flat elliptic-groove guide are analysed by using the mode-matching method and Mathieu function. The characteristic equations with the 1st and 2nd order approximations and their solutions for the dominant mode of the elliptic-groove guide are also obtained by a great quantity of theoretical analyses and numerical computations. The cut-off, dispersion and attenuation characteristics are in good agreement with those in the relevant references under limiting conditions and are discussed in detail. The obtained results are of important significance for theoretical researches and actual applications of elliptic-groove guides for millimeter and submillimeter waves.     

Transmission Characteristics of Ridge Waveguide Loaded with Left-Handed Materials

This paper presents a numerical study of the electromagnetic wave propagation in a double ridge waveguide, loaded with left-handed materials (LHM). The LHM is defined phenomenologically by assigning to it a negative permittivity and negative permeability simultaneously. Transmission characteristics such as cutoff wavelength, single-mode bandwidth, dispersion and field patterns have been investigated by edge-based finite element method. The results are compared to those with air- and dielectric-loaded ridge waveguide. It was found that the LHM-loaded ridge waveguide can greatly increase the cutoff wavelength with the disadvantage of a dramatic reduction in the single-mode bandwidth. The behavior of the dispersion curve of LHM-loaded ridge waveguide is similar to the cases of waveguide loaded with air or dielectric, except for a significant improvement of the propagation constant. The boundary conditions at the interface between the air and the LHM have been well illustrated and the antiparallel wave vector in LHM were obtained by considering the field patterns. The unusual behaviors of the LHM-loaded ridge waveguide provides the potential opportunities to design novel microwave and millimeter devices.     

Transmission Characteristics of Dielectric Tube Leaky Waveguide

Loss formula of the dielectric tube leaky waveguide is derived by using a transverse transmission-line model which carries most of the transmitted power in air inside a dielectric tube. It is shown that low-loss leaky waveguide can be realized in optical through submillimiter wavelengths with moderate guide parameters and the transmission loss does not depend strongly on the material losses. It is also shown that the attenuation constant of this leaky waveguide is smaller than that of the hollow waveguide by several orders of magnitude.     

脊波导TM模的FDTD分析

为了进一步分析脊波导,应用FDTD研究了脊波导在TM模式下脊位于不同位置时的TM11模式截止频率＋并给出了单脊波导的TM11模截止频率在脊位于不同位置时变化规律,还有TM模瞬态场图和频谱图。     

电介质/金属型红外空芯波导的传输特性和结构设计

由普通空芯波导的模式结构和传输性质出发,讨论了电介质/金属型空芯波导的传输特性,分析了HE11模在红外波段的低损耗传输条件。并在此基础上设计了电介质/金属型空芯波导的最佳结构,对膜系的选择也提供了明确的指导。     

LiNbO3光波导DBR结构透射特性分析

本文采用等效波导光栅Ｆ－ｐ腔方法分析了有耗情况下ＬｉＮｂＯ３光波导ＤＢＲ结构的透射特性，给出了利用这一结构设计电光强度调制器以及电调频分器的方法。     

四脊矩形波导的传输特性

应用有限元分析方法计算了对称四脊矩形波导TE模式的传输特性,即截止波长和场结构图传输特性。分析了传输特性随四脊矩形波导结构尺寸的变化关系曲线,得到脊间距越小,相对的截止波长越大。四脊矩形波导中主模的截止波长可随脊宽的变化而变化,在脊间距d/b一定的情况下,截止波长在s/a=0.4时比在其他尺寸时大。这些结果和计算数据将为四脊矩形波导器件的小型化提供指导。     

有耗介质导波结构的高次杂交四边形边缘元分析

本文提出了一种高次杂交四边形边缘元方法。讨论了这种高次杂交边缘元的有限元空间构造，给出了其形函数的显形表达式。这种方法不仅消除了伪解而且能直接求解传播常数，从而无需迭代便能分析有耗介质导波结构的传输特性。对矩形导和条形介质填充波导本征模传播常数的计算表明这种高次杂交边缘元的计算精度比低次杂交边缘元要高出一个量级。     

Matlab求解方同轴波导的截止波长和特性阻抗

采用有限差分法利用Matlab求解了方同轴波导的特性阻抗和高次模的截止波长并画出了场结构图,将所得数据与国外文献数据进行了对比,证明了有限差分法结合Matlab在分析简单截面的同轴波导时是简单可行的,而且计算精度较高,通用性强,可以用于传输线工程问题的设计和计算.最后计算了矩形同波导和偏心同轴波导的相关数据,用于与方形同轴波导对比.