Abstract
Experience with the vector fitting algorithm for rational approximation of frequency domain responses has in some situations revealed problems with slow convergence. A typical example is the fitting of noisy responses. The problem is linked to a high frequency asymptotic condition of the nontriviality constraint used in the vector fitting formulation. Relaxation of the non-triviality constraint is shown to be an effective solution to this problem. Application to selected examples demonstartes a significant improvement of performance in terms of convergence speed and the accuracy of the final result. Copyright IEEE
