Extrapolation with the matrix pencil method to combine low-frequency and high-frequency electromagnetic scattering results

Abstract

Accurate frequency domain solutions of electromagnetic scattering problems are known to require high computing resources as the solution frequency increases. On the other hand, high-frequency techniques provide us solutions with limited accuracy in the relatively high-frequency regions. In this thesis we aimed to fill the intermediate gap by using extrapolation techniques. Matrix pencil method (MPM) is presented to find the parameters of the model in our model-based extrapolation approach. In order to fully incorporate the two separate available data sources, i.e., accurate low-frequency solvers and asymptotic high-frequency solvers, we proposed two methods of coupling, namely coupled MPM and coupled deconvolution MPM. Results of proposed extrapolation methods are tested both on analytically generated backscattering solution of conducting sphere and numerical solutions of various three dimensional bodies.