An Equivalent Circuit Modeling Method of Near-field Probe Based on Vector Fitting Algorithm

In this paper, based on vector fitting (VF) algorithm, a precise equivalent circuit modeling method of a near-field probe with the bandwidth of 500MHz~1.5GHz can be constructed. Based on the S-parameters and the impedance magnitude/phase curves from the near-field probe and the related equivalent circuit model, the validity and flexibility can be demonstrated.

I. Introduction

In recent years, many studies demonstrate the vector fitting (VF) algorithm [1] is suitable for the equivalent modeling method of equipment under test (EUT). In [2], the vector fitting method is used to construct a wide-frequency model for aircraft wound-rotor synchronous machine. In [3], a time-domain analysis of RF and microwave autonomous circuits by vector fitting (VF) approach is proposed. However, it does not give a specific VF circuit model. Reference [4] investigates VF algorithm variants for frequency-domain impedance modelling of converters in different control modes, and analyzes different VF algorithm variants and their accuracy in modelling converter systems. In [5], a high-frequency motor model is construct based on VF method.