Generation of Wideband Electromagnetic Responses Using Early-Time and Low-Frequency Data

Abstract

This Chapter introduces a new approach to generate wideband and temporal response for three-dimensional conducting structures. It is accomplished through the use of a hybrid method that involves generation of early-time and low-frequency information for the electromagnetic structure of interest. The early-time and low-frequency information are complementary and contain all the necessary information for the ultra-wideband electromagnetic response of the system at a specific spatial location. The time domain response is modeled by a Laguerre series expansion. The frequency domain response is also expressed in an analytic form using the same expansion coefficients used in modeling the time domain response. Data in both domains are used to solve for the polynomial coefficients by data fitting. Once the unknown polynomial coefficients are obtained, data of interest are concurrently extrapolated in both domains. This approach is attractive because expansions with a few terms give good extrapolation in both time and frequency domains, with minimum computation time.