传输线瞬态响应的一种时域分析方法

提出一种传输线瞬态响应的时域分析方法。该方法对电报方程在时域内差分离散,在建立对空间的一阶微分方程组后,采用精细积分法,可获得传输线瞬态响应。这是一种时域内的半解析数值计算方法,具有方法简单、计算精度高等优点,能够有效地分析具有非线性负载的有损耦合传输线瞬态响应问题,也可以用于输电线路的瞬态分析及故障测距。     

基于精细积分法的耦合传输线瞬态分析

在耦合传输线的瞬态分析中提出了一种基于精细积分法的龙格-库塔迭代法。这是一种时域内的数值解法，该方法在对电报方程进行空间离散而获得对时间的一阶微分方程之后，没有采用精细计算法，而是采用了龙格-库塔迭代法。避免了大量的矩阵运算，提高了传输线瞬态响应分析的效率。     

无线电设备、电信设备

TN811+.32005060647基于精细积分法的耦合传输线瞬态分析/辛丙松,赵进全,杨拴科(西安交通大学电气工程学院)//光纤与电缆及其应用技术.―2005,(1).―15～17.在耦合传输线的瞬态分析中提出了一种基于精细积分法的龙格-库塔迭代法。这是一种时域内的数值解法,该方法在对电报方程进行空间离散而获得对时间的一阶微分方程之后,没有采用精细计算法,而是采用了龙格-库塔迭代法。避免了大量的矩阵运算,提高了传输线瞬态响应分析的效率。图5表0参6TN8132005060648同轴电缆皱纹导体用整体型轧制模片的设计/包晓刚,宣维刚(中国电子科技集团公司第二…     

非均匀耦合传输线时域响应分析的精细积分法

本文利用精细积分法对非均匀耦合传输时域响应进行了分析。该方法与传统方法的区别是自然考虑非均匀传输线的非均匀性,没有对传输线进行特殊处理,并且也不需要对耦合的电报方程进行解耦处理。将精细积分法应用到非均匀耦合传输线时域响应分析之中,极大地简化了分析,提高了精度和效率,是非均匀耦合传输线时域响应分析中的一种新方法。     

传输线瞬态分析中基于电报方程时-空离散的有效方法

本文对基于电报方程时-空变量同时离散的传输线瞬态分析方法作了重新研究.利用传输线上电压电流的波动传播特性,导出了有效的传输线瞬态分析模型;提出了用Lax-Friedrichs差分格式消除因空间坐标离散化导致的解的寄生振荡的方法;给出了模型在一般电路模拟器中的变步长实现;最后用实例作了验证.通过这些工作说明这一原始而基本的方法事实上可应用于最一般的非均匀频变传输线,并具备目前流行的采用有理逼近的频域方法同等的效率.     

高速PCB板暂态响应的一种合成数值算法

随着高速PCB板上信号传输速度的不断增加,有损传输线的暂态分析的重要性与日俱增。本文首先将传输线数学模型-电报方程-离散化为高阶常微分方程组,在满足稳定性条件下正确选择时间、空间步长,利用微分方程数值解法编程求解。该方法具有精度高计算时间少的优点。     

激光表面重熔过程中流体流动和传热的数值模拟

在PHOENICS软件基础上开发了模拟激光表面重熔过程温度场和速度场的数值程序 ;温度场和速度场的计算采用了固定网格及处理熔化和凝固问题的一般源项方法 ;移动热源引起的能量和动量变化分别作为附加源项构建控制方程组 ,采用控制容积积分法对控制方程进行离散和求解 ;对铝合金激光表面重熔过程中的传热、相变及流体流动问题进行了三维非稳态的数值模拟研究。     

双导线传输线BLT方程的离散化方法

基于Beam Liu Tesche方程(以下简称BLT方程),采用离散化方法来求解双导传输线的频域和时域终端响应.对于离散化的双导线模型,应用Agrawal模型分布源,首先获得了BLT方程在频域上的离散化计算公式.接着采用Fourier逆变换,获得BLT方程在时域上的离散化计算公式.采用这两个离散化计算公式,当知道在导线上的激励源分布的离散数据时,就可以计算线路终端频域或者时域的感应电压和电流.最后针对平面波激励源进行数值仿真试验.     

有耗互连线瞬态模拟的稳定递归算法

本语文提出了一种用于求解高速ＶＬＳＩ和多芯片组件（ＭＣＭ）中有耗互连线瞬态响应的稳定递归算法。在频域内,均匀传输线两端的电压电流以满足一针这组公式利用Ｔａｙｌｏｒ级数进行近似,通过逆拉氏变摸得到一组时域内的递归公式。递归公式只涉及到传输线两端的电流和电压,瞬态响应可以步进求解。递归公式中的卷积只与已经计算出的数值有关,不涉及任何未知量。本方法避免了有理逼近所导致的不稳定性,是绝对收敛的。数值实验结     

基于传播子技术的辛时域多分辨率方法

 数值求解三维时域Maxwell方程的过程中,保持方程的内在结构显得尤为重要.利用Hamilton函数的变分形式,将Maxwell方程表述为Hamilton正则方程形式.在时域方向,利用辛传播子技术对方程进行离散以保持方程的内在结构;在空域方向,采用时域多分辨率方法对三维旋度算符进行差分离散,建立了求解Maxwell方程的辛时域多分辨率(S-MRTD)方法.对S-MRTD方法的稳定性及数值色散性进行了系统的探讨,数值结果表明该方法的正确性及高精度性.     

Analysis of the time response of multiconductor transmission lineswith frequency-dependent losses by the method ofconvolution-characteristics

A new method for analysis of the time response of multiconductor transmission lines with frequency-dependent losses is presented. This method can solve the time response of various kinds of transmission lines with arbitrary terminal networks. Particularly, it can analyze nonuniform lines with frequency-dependent losses, for which no effective method for analyzing their time response exists. This method starts from the frequency-domain telegrapher's equations. After decoupling and inversely Fourier transforming, then a set of decoupled time-domain equations including convolutions are given. These equations can be solved with the characteristic method. The results obtained with this method are stable and accurate. Two examples are given to illustrate the application of this method to various multiconductor transmission lines     

On the limitation of the weak-coupling assumption for crosstalkanalysis based on quasi-TEM propagation

The limitation of the weak-coupling assumption for the case of two transmission lines with a common ground is examined. The analysis is based on the mathematical structure of solutions to the telegrapher's equations, and, therefore, quasi-transverse electromagnetic (TEM) propagation is assumed. All loss is neglected, and the lines are assumed to be symmetric. Requirements that are necessary for the weak-coupling assumption to hold in a homogeneous medium as well as in a medium that possesses certain types of inhomogeneities are derived by examining both the fully coupled and the weakly coupled forms of the telegrapher's equations. It is shown that terminating impedances influence the validity of the weak-coupling solution locally to resonances but have little effect elsewhere. Theoretical and experimental results are given in both the frequency and time domains for several geometries. A solution to the weak-coupling form of the telegrapher's equations is provided     

Properties of and generalized full-wave transmission line modelsfor hybrid (Bi)(an)isotropic waveguides

In this paper single and coupled equivalent transmission lines are developed for the propagation of modes in reciprocal and nonreciprocal, anisotropic, bi-isotropic, and bi-anisotropic waveguides. The transmission lines are described by the generalized telegrapher's equations. In order to develop these transmission line models some properties related to reciprocity, bi-directionality, and mirroring, of general waveguides and generalized transmission lines are investigated. The transmission line models are based on the reciprocity theorem and are valid for arbitrary frequencies     

Clarification of a decoupling method for multiconductortransmission lines

The authors provide a clarification of a decoupling method employed in the analysis of multiconductor transmission lines. They show that the use of a similarity transformation yields more efficient and stable numerical algorithms for computation of eigenvalues and characteristic impedance/admittance matrices of the telegrapher's equations than those based on a congruence transformation. The algorithms are easy to implement in existing software and, thus, their utilization is recommended     

Impedance matching for complex loads through nonuniformtransmission lines

A numerical method for designing nonuniform transmission lines (NTLs) to match complex loads is presented. This method is based on solving an inverse problem derived from the telegrapher's equation. The matched NTLs are expected to have bandpass characteristics covering the sampling frequency points. A numerical algorithm is provided and verified by examples     

A SPICE model for incident field coupling to lossy multiconductortransmission lines

An efficient time-domain macromodel for incident field coupling to lossy multiconductor transmission lines is presented. The model takes the form of ordinary differential equations and can be easily included in SPICE like simulators for transient analysis. The model is based on the closed-form matrix-rational approximation of the exponential matrix describing telegrapher's equations and semi-analytic rational approximation of forcing functions     

A Precise Time-Step Integration Method for Transient Analysis of Lossy Nonuniform Transmission Lines

This paper presents a novel time-domain integration method for transient analysis of nonuniform multiconductor transmission lines (MTLs). It can solve the time response of various kinds of transmission lines with arbitrary coupling status. The spatial discretization in this method is the same as the finite-difference time-domain (FDTD) algorithm. However, in order to eliminate the Courant-Friedrich-Levy condition constraint, a precise time-step integration method is utilized in time-domain calculation. It gives an analytical solution in the time domain for the spatial discretized Telegrapher's equations with linear boundary conditions. Large time steps can be adopted in the integration process to achieve accurate results efficiently. In the analysis of transmission lines with frequency-dependent parameters, a passive equivalent model is introduced, which leads to the similar semidiscrete model as that for the frequency-independent case. In addition, a rigorous proof of the passivity of the model is provided. Numerical examples are presented to demonstrate the accuracy and stability of the proposed method.     

任意负载有损传输线时域响应的精细积分法

精细积分法能够有效地对有损传输线时域响应进行分析。通过对精细积分法进行改进 ,使其不仅能够在时域内很容易地处理具有电抗性质的负载 ,还可容易地处理如短路、开路这类传统FFT法难以解决的特殊的传输线时域响应问题 ,极大地提高了精细积分法分析传输线时域响应的功效