Frequency sweep of the field scattered by an inhomogeneous structure using method of moments and asymptotic waveform evaluation

In many radar applications it is necessary to determine the scattering from an object over a wide frequency band. The asymptotic waveform evaluation (AWE), which is a moment matching (MM) technique, constitutes a method to this end. In general, MM techniques provide a reduced-order model of a function. Using AWE-MM a linear system is expanded in terms of a Taylor series to obtain a fast frequency sweep of the linear system. If the structure of interest is inhomogeneous the MoM solution must be dictated by an integral equation that takes the variation of the electric properties of the structure into account. To the knowledge of the authors the AWE technique has not previously been applied to a MoM solution based on this kind of integral equation. It is the purpose of this paper to investigate the use of the AWE technique as a tool to obtain a fast frequency sweep of the field scattered by an inhomogeneous structure. The investigations concern 2-dimensional (2-D) configurations and TM-polarization.