Using natural-mode basis functions to represent broadband responses of a thin-wire scatterer

A method of augmenting the singularity expansion method (SEM) is proposed to facilitate numerical calculations by addressing the slow convergence of the SEM series. This augmentation is a first step in applying natural modes (NMs) to antenna modeling. The series is augmented by adding to each modal coefficient polynomial functions whose unknown weights are determined by satisfying boundary conditions. Improved convergence is demonstrated for a thin-wire scatterer illuminated by a plane-wave excitation.