A comparison of different approaches for the simulation of nonlinear transmission lines

In this work, a detailed analysis of two different approaches to the simulation of nonlinear transmission lines (NLTLs) is presented. Distributed and lumped-element models have been compared, and it has been shown that the latter (and simpler) approach provides a good description of NLTL behavior when the per-section capacitance of the line is smaller than the lumped nonlinear capacitance. Filtering aspects of NLTLs under large-signal driving conditions have been studied with the use of a harmonic balance simulation that avoids the need to linearize the circuit. This is the first time that this powerful simulation tool has been used to study the transmission Properties of NLTLs. The results are compared to those obtained by means of a conventional small-signal S-parameter simulation and effects related to large-signal driving conditions, such as the influence if the input power level and the degree of nonlinearity, are presented, (C) 2002 Wiley Periodicals, Inc.