不等长非均匀有损耗传输线FDTD瞬态分析

以分析等长均匀无损耗多导体传输线的时域有限差分(FDTD)法为基础,在考虑传输线损耗的情况下,对不等长非均匀多导体传输线进行分析。首先,在考虑传输线损耗的情况下给出传输线上各点电压和电流的迭代计算公式;其次,利用该公式对不等长非均匀有损耗传输线模型进行数值计算和理论分析;最后,通过仿真实验,其结果表明所提计算方法是正确和有效的。该方法对不等长非均匀有损耗传输线的研究提供理论计算参考。     

微带天线巴仑的准静态分析

提出了一种分析微带天线巴仑的数值方法。该方法具有计算简便，物理意义清晰，且不受巴仑的几何形状限制等优点，对实例计算结果和测量结果的比较表明，该方法是可行和有效的，并可加以推广，用来分析其它类型的多导体非均匀传输线。     

端接非线性负载的非均匀传输线瞬态分析

在均匀多导体传输线的时域有限差分法(FDTD)基础上，对非均匀多导体传输线及端接非线性负载的情况进行了分析。结果表明：对于非均匀多导体传输线，采用FDTD法进行瞬态分析极为方便，并且可以处理端接非线性负载的情况；同时，还可获得线上各点的电压、电流波过程。通过实例验证了所提出的FDTD算法的有效性，可用于传输线波过程的研究。     

非零初始状态传输线瞬态分析

本文结合付里叶变换和拉氏变换技术，得出了具有任意非零初始电压、电流分布的多导体传输线的等效时域线性网络模型，传输线可以为有耗丰均匀性，该模型可与常用电路分析软件接口，因而可处理非线性终端负载，给出了一个应用本文模型进行瞬态分析的例子。     

分析多层介质多导体传输线的区域分解法

本文利用区域分解法 ,将直线法和有限差分法结合起来 ,用于计算多层介质中具有任意截面形状多导体传输线的电容和电感矩阵。通过在纯介质区域使用直线法 ,导体所在区域使用有限差分法分别进行求解 ,充分发挥两种方法各自的优越性。直线法中快速傅里叶变换的引入进一步提高了算法的计算效率。数值结果表明 :该方法是有效的 ,且计算时间与介质层的厚度无关。文中还研究了介质层分界面的不平整性对传输线电磁参数的影响。     

计算传输线平均耦合截面积的一种高效全波方法

在功率平衡法的网络化公式应用中,精确预知腔内装载物的耦合截面积是关键,这通常依赖于混响室的实验测定.文中使用平面波角谱概念和蒙特卡罗方法来数值模拟混响室中的电磁环境,在此基础上,首次应用基于互易定理的快速全波分析方法提取了理想混响室内靠近理想导电地平面的多导体传输线的平均耦合截面积,验证了方法的正确性,并计算了单根裸线传输线、带包层传输线、双绞传输线、传输线附近有导体挡板以及多导体传输线端口的平均耦合截面积.该方法具有计算精度高、仿真速度快、适用范围广的特点.     

多导体传输线高频分布参数分析

多导体传输线高频场线耦合研究是当前电磁兼容研究的重点和难点,而多导体传输线上的耦合响应与线上的高频分布参数紧密相关。由于经典传输线理论中采用准TEM波近似,使其不适用于求解高频分布参数。为此,从基于TLST理论的非均匀多导体传输线高频场耦合模型出发,对多导体传输线高频分布参数进行了研究和分析,计算出多导体传输线上的沿线单位长度高频分布参数,并将其与利用经典传输线理论计算得到的结果进行了比较,对二者的差异进行了分析,最后通过高频场线耦合算例说明了本文高频分布参数计算的正确性。     

用网络级联法分析非均匀多导体传输线的时域响应

本文将非均匀多导体传输线等效为一系列多端口子网络的级联,各子网络近似为长度很短的均匀传输线构成,转移矩阵可由将其解析表达式展开为无穷矩阵级数进行计算。当子网络数目增大时,展开级数的收敛速度加快,仅保留几个低次项就能达到很高的精度。求出总级联网络的转移矩阵后,利用付里叶变换和卷积技术,便可进行信号时域响应分析。能分析的非均匀传输线可以具有频变参数和任意非线性端接负载。     

一种用于分析高速VLSI中频变互连线 瞬态响应的精细积分算法

本文利用精细积分法求解高速VLSI中频变参数互连线的瞬态响应.首先,从频域传输线方程出发,利用反拉氏变换将其转化为含有卷积项的时域方程,经过空间坐标离散后,再采用精细积分法进行求解.与以往的空间离散方法相比较,提出采用电压和电流空间间隔取点的方法,减小了截断误差.在计算常微分方程组中的非齐次项时,采用递归计算代替传统数值卷积大大提高了计算的效率.该方法对于耦合传输线无须进行解耦,在处理非均匀频变传输线时也非常方便.数值实验结果表明,该算法稳定性好,计算精度高.     

任意截面的非平行多导体传输线瞬态分析

以分析多导体传输线的时域有限差分(FDTD)法为基础,在考虑任意截面传输线分布参数无法直接计算的情况下,提出MOM-FDTD 混合方法对不平行多导体传输线进行瞬态分析。首先,利用FDTD建立多导体传输线时域差分模型,然后用MOM 法计算任意截面形状的非平行传输线的分布参数,并且与FDTD法混合进行瞬态分析计算。此算法相对于全波算法,在时间与存储空间消耗上具有很大的优势,并且满足精度要求。最后通过同轴传输线与矩形带状线的例子验证这个方法是正确有效的。     

ANALYSIS OF MULTICONDUCTOR TRANSMISSION LINES USING THE MACCORMACK METHOD

I. Introduction With the increasing signal speed and decreasing feature size of modern high-speed integrated circuits, the effects of transmission lines, such as delay, crosstalk, and signal distortion, become very impor- tant[1?3]. Coupling between transmission lines must be considered in circuit analysis. When multicon- ductor transmission lines are studied, they are usu- ally decoupled first[4?9]. The decoupling processes are similar and all have the diagonalization of pa- rameter matrices…     

Time-domain analysis of lossy multiconductor transmission lines based on the Lax–Wendroff technique

Taking advantage of the hyperbolic characteristics of the telegrapher equations, this paper applies the Lax–Wendroff technique, usually used in fluid dynamics, to transmission line analysis. A second-order-accurate Lax–Wendroff difference scheme for the telegrapher equations for both uniform and nonuniform transmission lines is derived. Based on this scheme, a new method for analyzing lossy multiconductor transmission lines which do not need to be decoupled is presented by combining with matrix operations. Using numerical experiments, the proposed method is compared with the characteristic method, the fast Fourier transform (FFT) approach, and the Lax–Friedrichs technique. With the presented method, a circuit including lossy multiconductor transmission lines is analyzed and the results are consistent with those of PSPICE. The nonlinear circuit including nonuniform lossy multiconductor transmission lines is also computed and the results are verified by HSPICE. The proposed method can be conveniently applied to either linear or nonlinear circuits which include general transmission lines, and is proved to be efficient.     

非平行微带线间的串扰抵消研究

非平行微带线是印刷电路板(PCB)上不可避免的互连结构。针对PCB 上非平行微带线间的串扰问题,用平行微带线近似非平行微带线,把平行耦合微带线间的串扰抵消方法应用到非平行耦合微带线中,提出了利用耦合传输线信道传输矩阵方法来进行远端串扰抵消,在对非平行耦合传输线信道传输矩阵进行特征值分解的基础上构建串扰抵消电路。仿真了非平行微带线间夹角分别为q=3°、5°、10°时的串扰,结果表明,该方法可以有效改善非平行微带线上信号眼图的质量,串扰抵消效果良好。     

Comparison of precoding schemes for digital subscriber lines

Precoding at the transmitter side is a practicable method for transmission over intersymbol interference channels. In contrast to decision-feedback equalization no error propagation occurs and coded modulation can be applied as for the intersymbol interference free channel. Tomlinson-Harashima (1971, 1972) precoding and flexible precoding are analyzed and compared. The dualities and differences are discussed. The focus of interest is the application of precoding to fast digital transmission over twisted pair lines, such as high-rate or asymmetric digital subscriber lines. It turns out that flexibility-which is not necessary in the specific application, digital subscriber lines-of flexible precoding is paid with a performance loss compared to Tomlinson-Harashima precoding     

Duality transformation for nonreciprocal and nonsymmetrictransmission lines

Duality transformation is introduced to the theory of generalized (nonreciprocal and nonsymmetric) transmission lines making it possible to find solutions to problems in terms of solutions to dual problems without having to go through the solution process. The generalized transmission lines have emerged when more general media have been introduced to classical waveguide geometries, for example, microstrip lines on chiral substrates. It is seen that there actually exist two duality transformations and the self-dual voltage and current solutions are propagating waves in the transmission line. The transformation can be, e.g., applied to transform a nonsymmetric transmission line to a symmetric one     

Raised trigonometric and hyperbolic power lines

A method is described for determining the solutions of transmission lines with various trigonometric and hyperbolic distributions which have not been embraced by any previous general class of lines. It is shown that Su's lines can be deduced from the corresponding power lines.     

复杂截面同轴线特性阻抗、截止波长的计算

应用静电场的观点和导波传输理论,用有限元法（FEM）分别计算了各种复杂截面同轴线特性阻抗、截止波长。计算结果表明,该方法计算精度高,通用性强,简便易行,可以用于传输线工程问题的设计和计算。     

Analysis of the time response of nonuniform multiconductortransmission lines with a method of equivalent cascaded network chain

Nonuniform multiconductor transmission lines are considered to be equivalent to a cascaded chain of many multiport subnetworks which are made of short sections of uniform lines. The ABCD matrices of the subnetworks can be obtained by the matrix series expansions of their analytic expressions. As long as the number of the subnetworks is large enough to reflect the line nonuniformity fully, the expansions will converge so fast that a few of low-order series terms will be good approximations. After the overall ABCD matrix of the cascaded network chain is evaluated from that of each subnetwork, the time of response of transmission lines can be analyzed. The lines may have frequency-dependent parameters and arbitrary nonlinear terminals. Furthermore, transmission systems with branches uniform and nonuniform transmission lines can be studied with this method conveniently. The analysis accuracy and efficiency are discussed in detail     

Applications of Optical Fibers for Overhead Transmission Lines

Optical fibers are increasingly in use for overhead transmission lines. Optical fiber cables for overhead transmission lines can be classified into three types; composite type, winding type, and self-supporting type. For the composite type, an FRP-covered optical fiber unit is suitable because of its good thermal and mechanical characteristics. Winding-type fiber cable is least expensive to install on existing overhead transmission lines. A dc arc test showed that the winding type can be applied to a ground wire because of its resistance to lightning. The winding type was applied to the ground wire of a 275-kV line, using a remote-controlled winding machine.     

外场作用双导线的电磁耦合时域分析方法

基于时域有限差分（finite-difference time-domain，FDTD）法和传输线方程，并结合插值技术，研究了一种高效的时域混合算法，能够快速模拟电磁波照射自由空间和屏蔽腔内双导体传输线的电磁耦合，并实现空间电磁场与双导线瞬态响应的同步计算.该算法先采用FDTD方法模拟双导线周围空间的电磁场分布，结合插值技术构建适用于双导线电磁耦合的传输线方程，再采用FDTD的中心差分格式进行离散，从而求解得到传输线和端接负载上的瞬态响应.同时，分析双导线间距对其电磁耦合的影响，掌握其耦合规律.通过相应数值算例的模拟，并与FDTD方法进行对比，验证了该时域混合算法的正确性和高效性.