Research On Time-step Integration Method On Transient Analysis Of Nonuinform Lossy Multiconductor Transmission Lines

Transmission lines are the foundation of various kinds of circuit systems and themedia of energy and information. With higher rise frequence, integrated scale andhigher operating speeds in very large scale integrated (VLSI) circuits, interconnects arebeing responsible for circuit signal integrity and system overall performance, becauseinterconnect effects such as delay, reflection, mutation and crosstalk caused byinterconnecting lines may result in wrong working of circuits and false actions ofsystems.In this paper, the interconnect effects caused by interconnecting lines aresummarized. Then it introduces domestic and international research present status andmain research methods of transmission lines and signal integrity of circuit systems.Subsequently, the electricwave equations are deduced according to equal concentratedparameter model of transmission lines and the finite-difference time-domain method hasbeen particularly studied. Finally, this paper presents a time-step integration method ontransient analysis of nonuniform lossy multiconductor transmission lines. This methodfirstly discretizes the spatial derivatives in the electricwave equations by differencewhile the temporal derivatives remain unchanged, then a set of semidiscretized timeequations can be obtained. Then it calculates the time integral of the temporalderivatives by Trapezoid integral method. In this way, current and voltage equations oftransmission lines using the time-step integration method can be obtained. The methodis used to simulate the models with linear loads and nonlinear loads in the state ofunequal and equal length nonuniform lossy multiconductor transmission lines. Theresults of simulation have shown that the presented method is effective and correct. Thismethod can effectively get rid of the unstable calculating result caused by the centraldifference, obtain current and voltage transient waveform on arbitrary point oftransmission lines, and is effective on transient analysis of transmission lines in longtime. At the same time this method does not need to decouple nonuniform lossymulticonductor transmission lines, reduce the operate quantity and increase the speed ofthe algorithm.