Bias in extrapolating responses from resonant structures using early-time and low-frequency data

In this work, a response of a resonant structure is represented as a finite sum of weighted orthogonal polynomials and pole terms. The driving-point current of a resonant antenna is extrapolated with each pole-estimation method and accuracy is studied as a function of the amount of early-time and low-frequency data used. Computational electromagnetic (CEM) methods are often used to numerically compute a wide-band EM response of a structure in either the time or frequency domain.