SIMULTANEOUS RECONSTRUCTION OF 2 PARAMETERS FROM THE TRANSIENT-RESPONSE OF A NONUNIFORM LCRG TRANSMISSION-LINE

A time-domain method to determine two of the physical parameters L,C,R , and G of a nonuniform transmission line, from the knowledge of the r emaining two parameters and the transient response of the line, is pre sented. The method is based on the recently introduced compact Green f unctions approach. It is shown that any pair of the parameters can be reconstructed if L and C are considered in terms of the characteristic impedance Z and the wavefront speed c. The impedance is assumed to be continuous along the nonuniform line, but may be discontinuous at the end. It is shown that a discontinuity at the end both simplifies the reconstruction and makes the reconstruction less sensitive to noise. T he parameters R and G, which both represent losses, are the most diffi cult to reconstruct. It is found that reconstructions involving c as w ell as reconstructions of R and G fail under certain conditions, at ce rtain points along the line. The method is tested numerically for all combinations of parameters, and the failure to determine the parameter s at some points is illustrated. The influence of noise is also illust rated. The present method should be useful as a fast analysis tool for time domain reflectometer measurements.