A Note on the Multiplicity of Poles in the Vector Fitting Macromodeling Method

Author

Deschrijver, Dirk ; Dhaene, Tom

Author_Institution

Dept. of Math. & Comput. Sci., Antwerp Univ.

Volume

55

Issue

4

fYear

2007

fDate

4/1/2007 12:00:00 AM

Firstpage

736

Lastpage

741

Abstract

Vector fitting is a robust macromodeling tool for rational approximation of spectral data obtained by full-wave electromagnetic simulators or high-frequency measurements. The technique iteratively calculates a suitable set of poles, and solves the residues of the transfer function in a two-step procedure. If poles with a higher order multiplicity occur during the pole-identification step, numerical problems and inaccuracies can result, especially if the normal equations are solved. This problem is illustrated on an RLC filter, and a generalization of the basis functions is proposed to resolve the issue

Keywords

RLC circuits; filters; frequency-domain analysis; network synthesis; poles and zeros; time-domain analysis; transfer functions; RLC filter; basis function generalization; full-wave electromagnetic simulators; high-frequency measurements; pole identification; poles multiplicity; robust macromodeling tool; spectral data rational approximation; transfer function; vector fitting macromodeling method; Electromagnetic measurements; Equations; Filters; Frequency; Least squares approximation; Poles and zeros; Robustness; Time domain analysis; Transfer functions; Vectors; Macromodeling; rational approximation; vector fitting;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2007.893651

Filename

4148103