Over-modeling Reduction in Vector Fitting Identification for Stability Analysis of Microwave and RF Amplifiers

Abstract

[ENG] Over-modeling can be a critical problem for microwave circuit designers when doing a pole-zero stability analysis. Hence, in this project we will aim to develop a new technique and strategy to overcome this troublesome issue, or, to the extent possible, minimize its effects. To that end, we will create an automatic algorithm based on the state-of-the-art automatic Vector Fitting 1 algorithm for stability analysis [10] and a paper authored by S. Grivet-Talocia and M. Bandinu [11]. Moreover, we will implement it in Matlab, where —once the transfer function identified— the corresponding pole-zero diagram will be displayed in order to facilitate the interpretation of the results regarding the stability of the device under test. As an attempt to improve the state-of-the-art method, we will compare thoroughly the identifications carried out by both automatic algorithms. Thus, we will be able to determine the possible advantages of our contribution regarding over-modeling. Furthermore, bearing in mind the general scenario of this project, we will specifically assess the validity of these benefits for the stability analysis of microwave and RF amplifiers. Lastly, we will conclude by evaluating the limitations of the developed technique and by proposing ideas for a further work.