A fast algorithm for the analysis of scattering by elongated cavities

Abstract

Electromagnetic scattering from elongated, arbitrarily shaped, open-ended cavities (OEC) has been studied extensively over the years. In this paper, we introduce the fast encapsulating domain decomposition (EDD) scheme for the analysis of radar cross section (RCS) of such OEC. The EDD advantages stem from a domain decomposition along the elongated dimension, followed by a spectral representation of the fields in each segment, whereby the field is naturally separated into in- and out-going waves. This diagonalizes the translation between the cross sections, thus reducing the per segment computational complexity from to , where and are the number of aperture and wall unknowns per segment, satisfying as the segmentation is constructed to be smaller than the cross section. The results of the EDD are demonstrated on an S-shaped elongated open-ended cavity.

Keywords:

• Electromagnetic scattering
• higher order
• inlets
• integral equations
• LCN
• numerical methods
• open-ended cavity
• RADAR cross section
• RCS
• spectral methods

Abbreviations:

• DD – domain decomposition
• IO – input operator
• CIO – cavity IO
• LCN – locally corrected Nyström
• OEC – open-ended cavity
• IE – integral equation
• CC – computational complexity
• EDD – encapsulating DD
• NG – non-uniform grid
• SDD – segmented DD