PIER | |

Progress In Electromagnetics Research | ISSN: 1070-4698, E-ISSN: 1559-8985 |

Home > Vol. 150 > pp. 163-182
## RECENT ADVANCES IN THE ASYMPTOTIC THEORY OF DIFFRACTION BY ELONGATED BODIES (Invited Paper)By I. V. Andronov and R. Mittra
Abstract:
The asymptotic approach to the problem of high-frequency diffraction by elongated bodies is discussed in this work. The classical expansion is shown to require the frequencies to be too high for it to be applicable. Attempts to improve the approximating properties of the asymptotic methods are discussed. It is shown that effective approximations appear under the supposition that the squared transverse dimension of the body is proportional to its longitudinal size measured in wavelengths. This is referred to herein as the case of strongly elongated body and is examined in detail. It is assumed that the body has a rotational symmetry and can be well approximated by a spheroid. The cases of axial incidence and that of incidence at a grazing angle to the axis are considered. Both the asymptotics of the induced currents on the surface and of the far field amplitude are developed. Comparison with numerical results for a set of test problems shows that the leading terms of the new asymptotics provide good approximation in a uniform manner with respect to the rate of elongation. Some effects typical for scattering by elongated bodies are discussed.
2. Hönl, H., A. W. Maue, and K. Westpfahl, 3. King, R. W. P. and T. T.Wu, 4. Belkina, M. G. and L. A.Wainstein, "The characteristics of radiation of spherical surface antennas," 5. Belkina, M. G., "The characteristics of radiation of a prolate ellipsoid of revolution," 6. Hong, S., "Asymptotic theory of electromagnetic and acoustic diffraction by smooth convex surfaces of variable curvature," 7. Ivanov, V. I., "Computation of corrections to the Fock asymptotics for the wave field near a circular cylinder and a sphere," 8. Andronov, I. V., D. P. Bouche, and M. Duruflé, "High-frequency diffraction of plane electromagnetic wave by an elongated spheroid," 9. Senior, T. B. A., "Disk scattering at edge-on incidence," 10. Senior, T. B. A., "Loop excitation of traveling waves," 11. Bird, T. S., "Comparison of asymptotic solutions for the surface field excited by a magnetic dipole on a cylinder," 12. Andronov, I. V. and D. Bouche, "Asymptotic of creeping waves on a strongly prolate body," 13. Molinet, F., I. V. Andronov, and D. Bouche, 14. Engineer, J. C., J. R. King, and R. H. Tew, "Diffraction by slender bodies," 15. Komarov, I. V., L. I. Ponomarev, and S. Y. Slavyanov, 16. Abramowitz, M. and I. Stegun, 17. Andronov, I. V., "The currents induced by a high-frequency wave incident at a small angle to the axis of strongly elongated spheroid," 18. Thompson, I. J. and A. R. Barnett, "COULCC: A continued-fraction algorithm for Coulomb functions of complex order with complex arguments," 19. Andronov, I. V. and D. Bouche, "Forward and backward waves in high-frequency diffraction by an elongated spheroid," 20. Fock, V. A., 21. Andronov, I. V., "High frequency asymptotics of electromagnetic field on a strongly elongated spheroid," 22. Stratton, J. A. and L. J. Chu, "Diffraction theory of electromagnetic waves," 23. Andronov, I. V., "High-frequency acoustic scattering from prolate spheroids with high aspect ratio," 24. Andronov, I. V. and D. A. Shevnin, "High-frequency scattering by perfectly conducting prolate spheroids," 25. Andronov, I. V., "Diffraction of spherical waves on large strongly elongated spheroids," 26. Andronov, I. V., "Calculation of diffraction by strongly elongated bodies of revolution," 27. Andronov, I. V. and D. Bouche, "Diffraction by a narrow circular cone as by a strongly elongated body," 28. Andronov, I. V., "Diffraction by elliptic cylinder with strongly elongated cross-section," 29. Andronov, I. V. and R. Mittra, "Asymptotic theory of diffraction by elongated bodies - From V. A. Fock to present," |

© Copyright 2014 EMW Publishing. All Rights Reserved