圆波导壁上小孔耦合电磁能量分析

本文借助圆波导并矢格林函数 ,采用矩量法分析了任意平面波通过圆波导壁上小孔耦合到波导中的能量 ,计算了通过小孔的能量传输系数 ,该结果可用于复杂系统EMC预测。     

任意截面波导的小波矩量法分析

用离散小波矩量法推导出了任意截面波导的特征值方程,并以常见规则波导为例,对其截止波数进行数值计算,所得结果与理论值吻合良好,从而使小波矩量法求解波导问题的可行性和有效性得以验证;文中分别用矩量法和小波矩量法对矩形波导主模的截止波长进行计算,通过对比其运算时间和收敛速度,表明在保证精度的前提下,小波矩量法能有效提高运算速度。     

波导宽边纵向缝隙阵的分析

采用等效电路与矩量法相结合的方法，建立波导宽边纵向缝隙数学模型。它既克服了一般效电路分析方法无法进行频率特性分析的缺点，又克服了利用一般矩量法求解积分方程仅适应于几个缝的小阵的缺点。这种分析方法缝隙的辐射导纳是由矩量法直接求解的，与站平时征于谐振状态无关，因此，可以分析天线性能随频率的变化情况。介绍的分析方法包括一互耦，考虑了波导的壁厚、利用该分析方法，对宽边纵向缝隙阵端馈与中心馈电的两种情况进行     

月形波导和加片圆波导的解析分析

采用模匹配方法分析了月形波导和加片圆波导的截止频率。波导中的场采用半数阶Bessel函数展开并令其满足边界条件,从而获得截止频率的特征方程国。根据本文所给公式可求解任意尺寸的月形波导、倒月形波导和加片圆波导的截止频率,并获得稳定的、具有高精度的解。     

矩形波导纵缝归一化导纳的简单计算

基于矩量法的数学思想，推导并给出直接计算波导纵缝的近似解析表示式，利用该近似解析式计算所得结果与矩量法的计算结果吻合良好。     

NRD波导槽缝激励的严格分析

NRD波导的激励是平面／非平面微波混合集成电路的一个关键问题．文中采用并矢格林函数结合矩量法严格分析了通过横向缝隙有效激励NRD波导LSE01模的方法．该方法具有结构简单、体积小、耦合效率高、泄漏能量小等优点,对混合微波集成电路的设计具有重要的实际意义。     

波导宽边同缝隙阵的分析

采用等效电路与矩量法相结合的方法，建立波导宽边纵向缝隙阵分析的数学模型。它既克服了一般等效电路分析方法无法进行频率特性分析的缺点，又 克服了利用一般矩量法求解积分方程仅适应于分析几个缝的小阵的缺点。     

小型波导缝隙天线阵的改进设计方法研究

利用传输线理论构造负载阻抗的近似计算公式,采用数值逼近法直接计算阵列中的缝隙归一化导纳,从而可以在Elliott波导缝隙天线阵设计过程中避免使用感应电动势法和矩量法,进而可以提高设计速度.最后采用该方法设计了工作频率为9.375GHz的缝隙阵结构参数,仿真结果表明改进设计方法比较有效.     

非均匀填充波导截止频率的网络模型分解解法

本文给出一种求解非均匀填充波导截止频率的新方法,称为网络模型分解法。文中首先利用区域剖分和电磁场的微分形式理论建立了该问题的拓扑填型及其相应的网络模型,然后利用电路理论中的网络分解节点分析法建立了计算非均匀填充波导截止频率的一般算法。最后将该算法应用于若干典型实例,验证了方法的可行性和有效性。     

波导截面TM 波截止波数的快速计算方法

在计算任意波导截面TM 波截止波数的问题上,矩量法不可避免的要处理奇异点的问题,因此在快速性和简洁性上均存在很大不足。本文提出了一种便捷的计算方法:首先推导出相应截止波数下波导的电场积分方程,采用Gauss-Legendre公式将积分数值化,然后运用矩量法进行处理后得到一个矩阵方程,最后利用迭代法找出这个矩阵的特征值,从而避开了奇异点使得问题的求解更加便捷。     

用Cassinian变换FDTD方法分析几种特殊截面波导传输特性

本文把保角变换应用于紧凑格式2D/FDTD算法,给出了保角变换FDTD算法差分公式,提出了焦点的处理方法.用Cassinian变换分别计算了椭圆波导、茧形波导的截止波长与色散曲线,以及屏蔽平行双线高阶模的截止波长.     

Beam propagation analysis for tapered waveguides: taking account ofthe curved phase-front effect in paraxial approximation

A novel equivalent waveguide theory based on the conformal mapping method is employed to investigate the tapered waveguide with curved phase fronts. By using the theory, the curved phase fronts of a tapered waveguide would be transformed into the planar ones of its equivalent straight-liked structure. Therefore, the paraxial beam propagation method can be used to analyze the equivalent structures of tapered waveguides (even for wide-angle tapers). Two kinds of popular tapered waveguides, including the cross-sectional dimension tapering and the constant V-number tapering, are used to analyze by our combination of conformal mapping method and beam propagation method (BPM)     

Numerical Stability and Numerical Dispersion of Compact Conformal Mapping 2D-FDTD Method Used for the Dispersion Analysis of Waveguides

In dispersion analysis of waveguides with particular cross-section by compact 2D-FDTD method, using conformal-boundary coordinates can obtain high computational accuracy. The transformation from conformal-boundary coordinates to rectangular coordinates can be done by conformal mapping technique in order to match Yee algorithm. In this paper, numerical stability and numerical dispersion equation of compact conformal mapping 2D-FDTD (CCM-2D-FDTD) method are derived. It is shown that the upper limit of Courant number for CCM-2D-FDTD is always smaller than 1/√2. As an example, the dispersion equation is used to examine the impact of number of cell for circular waveguide.     

弯曲光波导端面修饰的设计方法

光波导的弯曲损耗一直是集成光学中一个值得人们重视的问题,为有效地减小光波导弯曲损耗,弯曲光波导的设计成为集成光学波导设计中的一个重要内容.本文在弯曲光波导保形变换方法的基础上,应用几何光学分析方法给出了波导弯曲损耗产生的简洁的物理图像,从而深入地分析了弯曲损耗产生的根本原因,并由此提出了弯曲光波导端面修饰的设计方法.理论分析表明,与传统的弯曲的光波导设计相比,该种设计方法可以有效地减小导波的模式泄漏,从而减小波导弯曲损耗.尤其是在弯曲光波导曲率半径、材料折射率等参数被设定的情况下,该种设计方法成为一种有效的设计方法.     

Conformal-mapping design tools for coaxial couplers with complex cross section

Numerical conformal mapping is exploited as a simple, accurate, and efficient tool for the analysis and design of coaxial waveguides and couplers of complex cross section. An implementation based on the Schwarz-Christoffel Toolbox, a public-domain MATLAB package, is applied to slotted coaxial cables and to symmetrical coaxial couplers, with circular or polygonal inner conductors and external shields. The effect of metallic diaphragms of arbitrary thickness, partially separating the inner conductors, is also easily taken into account. The proposed technique is validated against the results of the finite-element method, showing excellent agreement at a fraction of the computational cost, and is also extended to the case of nonsymmetrical couplers, providing the designer with important additional degrees of freedom.     

Analysis of abrupt bent waveguides by the beam propagation methodand the conformal mapping method

In this study, we propose a simple and applicable approach to analyze the large angle (larger than 100) abrupt bent waveguides. By using the conformal mapping technique, the abrupt bent waveguide is transformed into an equivalent straight one which the conventional (paraxial) beam propagation method (BPM) can be applied to analyze it directly. The field distribution in a 20° microprism type abrupt bent waveguide is also demonstrated by our method     

Study by conformal mapping of TE and TM waves in open dielectric waveguides

We show by suitable conformal mapping and appropriate boundary conditions that theHguide permits study on the Goubau line, theOguide, and the dielectric rod. By this method, we confirm a well-known result [10] and generalize about some new waveguides.     

悬置共面波导的基本参数

悬置共面波导兼有鳍线和悬置带线的优点。本文用共形变换技术分析悬置共面波导,得到严格的解,考虑有限基片情况下给出了悬置共面波导的有效介电常数,单位长度电容和特性阻抗的闭合表达。     

A general conformal-mapping approach to the optimum electrodedesign of coplanar waveguides with arbitrary cross section

The Schwarz-Christoffel toolbox, a free MATLAB package for the computation of conformal maps, is applied to the quasi-static analysis of coplanar waveguides (CPWs) of arbitrary cross section in order to provide computationally efficient and very accurate estimates of their capacitance, inductance, characteristic impedance, and skin-effect attenuation. A few examples of many-sided polygonal waveguides are discussed, and the trapezoidal CPW, important, for example, for electrooptic modulators, is described in full detail, providing general guidelines for the electrode geometry optimization. The technique is validated through a comparison with the results of a full-wave finite-element method, and excellent agreement is demonstrated both in vacuo and with two-layer dielectric substrates     

Basic characteristics of two layered substrate coplanar waveguides

The conformal mapping technique is used to obtain simple CAD oriented closed form expressions for the effective dielectric permittivity, line capacitance and impedance of two layered coplanar waveguides (CPWs)