The purpose of this paper is to investigate the uniqueness of thesolution of lossy lines with frequency-dependent parametersterminated with non-linear resistors. Several solutions that satisfythe same initial conditions may exist if the terminal resistors arelocally active. In these cases the uniqueness of solution is assuredadding parasitic capacitances in parallel to the voltage controlledresistors and parasitic inductances in series to the currentcontrolled resistors. In this way, among all the possible solutions,the only one that assures the time continuity of the current andvoltage waveforms at the ends of the line is captured. In the lightof these results, the properties of numerical models of thesedistributed circuits based on convolution techniques have beenstudied, and conditions assuring the uniqueness of the numericalsolution have been found. Numerical simulations, when based onqualitative information of this type, enable us to obtain thequantitative properties in an efficient manner. In particular, asimple numerical method that enforces artificially the timecontinuity of the solution is proposed to circumvent the need ofadding parasitics. Copyright
展开▼
