TY - JOUR
T1 - High-frequency methods for multiple diffraction modeling
T2 - application and comparison
AU - Polka, L. A.
AU - Balanis, Constantine
AU - Polycarpou, A. C.
N1 - Funding Information:
This work was supported by NASA Langley Research Center under Grant NAG-1-562 and by the ONR Graduate Fellowship Program. The Editor thanks P. H. Pathak, C. E. Ryan, and R. Tiberio for
PY - 1994
Y1 - 1994
N2 - The use of several high-frequency, asymptotic techniques is explored for modeling the scattering, using higher-order diffractions, of radar targets composed of two or more parallel edges with diminishing electrical separation between them. The Uniform Theory of Diffraction (UTD) is one of the most popular and easily applied techniques; however, difficulties in accurately modeling second-order diffractions are inherent in the method due to the failure of the technique in overlapping transition regions. The effectiveness of the UTD, as the electrical size of the target decreases, is explored using a square cylinder. Other high-frequency methods for dealing with fields in overlapping transition regions are reviewed. Particularly, the Extended Spectral Theory of Diffraction (ESTD) and the Extended Physical Theory of Diffraction (EPTD) are examined, and the EPTD is applied to the scattering by a strip. Results are compared with UTD and moment method (MM) data. A hybrid method, using the UTD plus the ESTD or the EPTD, is recommended for accurately predicting the scattering of radar targets, even of small electrical size, at all observation angles.
AB - The use of several high-frequency, asymptotic techniques is explored for modeling the scattering, using higher-order diffractions, of radar targets composed of two or more parallel edges with diminishing electrical separation between them. The Uniform Theory of Diffraction (UTD) is one of the most popular and easily applied techniques; however, difficulties in accurately modeling second-order diffractions are inherent in the method due to the failure of the technique in overlapping transition regions. The effectiveness of the UTD, as the electrical size of the target decreases, is explored using a square cylinder. Other high-frequency methods for dealing with fields in overlapping transition regions are reviewed. Particularly, the Extended Spectral Theory of Diffraction (ESTD) and the Extended Physical Theory of Diffraction (EPTD) are examined, and the EPTD is applied to the scattering by a strip. Results are compared with UTD and moment method (MM) data. A hybrid method, using the UTD plus the ESTD or the EPTD, is recommended for accurately predicting the scattering of radar targets, even of small electrical size, at all observation angles.
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U2 - 10.1163/156939394X01019
DO - 10.1163/156939394X01019
M3 - Article
AN - SCOPUS:0028494448
VL - 8
SP - 1223
EP - 1246
JO - Journal of Electromagnetic Waves and Applications
JF - Journal of Electromagnetic Waves and Applications
SN - 0920-5071
IS - 9-10
ER -