Awe Technique in Frequency Domain Electromagnetics

Abstract

This paper presents fast radar cross section (RCS) computations using the Asymptotic Waveform Evaluation (AWE) technique in conjunction with Method of Moments (MoM) and hybrid Finite Element (FEM/MoM) implementations. In its traditional form, AWE constructs a reduced-order model of a given linear system by Taylor series expansion with respect to specific values of the system parameters (frequency, angle, etc.). However, using a Padè rational function instead of a Taylor series, the accuracy of the analysis is increased to a wider frequency range. Thus, AWE permits the prediction of the frequency response from a few frequency calculations. AWE is also extended to allow monostatic RCS pattern prediction using again a few pattern values, thus eliminating a need to resolve the system when an iterative solver is employed. To demonstrate these extensions of AWE, numerical examples of three-dimensional metallic bodies and cavity-backed apertures are considered.