Adaptive Frequency Sampling Tools as AIDS in Electromagnetic Modeling and Design

In this paper, enhanced adaptive frequency sampling algorithms for robust electromagnetic (EM) modeling and computer aided design (CAD) are proposed. The algorithms are based on rational interpolation, which leads to more accurate RF/microwave models as compared to other existing interpolants, e.g. spline. Starting with a minimal number of support points, i.e. EM data and with lowest-order rational functions, the algorithms systematically produce rational function models, which meet user-specified accuracies. In each stage of the algorithms, additional poles and/or zeros are added, and new support points are adoptively selected based on a statistical criterion. The algorithms distinguish critical regions of an EM component´s behavior that need to be densely sampled and use relatively fewer data in other regions. The advantages of the proposed algorithms are shown via practical RF/microwave examples