PO with Modified Surface-Normal Vectors for RCS Calculation of Scatterers with Edges and Wedges

Nobutaka OMAKI  Tetsu SHIJO  Makoto ANDO  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E92-C   No.1   pp.33-39
Publication Date: 2009/01/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E92.C.33
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Electromagnetic Theory and its Application)
Category: 
Keyword: 
physical optics,  geometrical theory of diffraction,  physical theory of diffraction,  modified surface-normal vectors,  

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Summary: 
We have proposed a unique and simple modification to the definition of surface-normal vectors in Physical optics (PO). The modified surface-normal vectors are so defined as that the reflection law is satisfied at every point on the surface. The PO with currents defined by this new surface-normal vector has the enhanced accuracy for the edged scatterers to the level of Geometrical Theory of Diffraction (GTD), though it dispenses with the knowledge of high frequency asymptotic techniques. In this paper, firstly, the remarkable simplicity and the high accuracy of the modified PO as applied to the analysis of Radar Cross Section (RCS) is demonstrated for 2 dimensional problems. Noteworthy is that the scattering not only from edge but also from wedge is accurately predicted. This fringe advantage is confirmed asymptotically by comparing the edge and wedge diffraction coefficients of GTD. Finally, the applicability for three dimensional cube is also demonstrated by comparison with experimental data.