Applicability of time domain and z-domain Vector Fitting to rational modeling from time domain responses with consideration to circuit solver integration method

Linear macromodels can be extracted from simulated time domain responses, for instance using the Time Domain Vector Fitting (TD-VF) and the z-domain Vector Fitting (ZD-VF) method. In this paper we show that the TD-VF yields more accurate results than ZD-VF, mainly because of its ability to handle truncated responses. This makes TD-VF more applicable to practical applications. In addition, we show that with TD-VF one may in certain situations greatly improve the accuracy of the extracted model by introducing the same numerical integration method in the extraction routine as the one used by the circuit simulator.