1999 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

IEEE Transactions on Antennas and Propagation
Volume 47 Number 10, October 1999

Table of Contents for this issue

Complete paper in PDF format

Microwave Scattering from Dielectric Wedges with Planar Surfaces: A Diffraction Coefficient Based on a Physical Optics Version of GTD

R. E. Burge, X.-C. Yuan, B. D. Carroll, N. E. Fisher, T. J. Hall, G. A. Lester, N. D. Taket, and Chris J. Oliver

Page 1515.

Abstract:

The development is presented here, derived from a physical optics version of the geometrical theory of diffraction (POGTD) of a simple edge coefficient for external and internal diffraction at planar dielectric edges. This is required in connection with a simulator for synthetic aperture radar (SAR) images. The diffraction coefficient is assessed by comparison of calculations using POGTD, excluding multiple scattering processes, with an extensive set of experimental microwave scattering data on dielectric wedges and some corresponding calculations by the finite-difference time-domain method (FDTD) of solving Maxwell's equations. The experimental results were gained from dielectric wedges of four wedge angles, each for a wide range of angles of incidence, separately for TE and TM plane polarized components, and for two sets of wedges with different dielectric constants. The intensity distribution found by using the diffraction coefficient for external diffraction is found to be in good agreement with both experiment and calculations using FDTD. For internal wedge diffraction, POGTD predicts an intensity distribution of similar angular shape to the experimental but, due to the neglect of absorption, the intensity level is too high.

References

  1. N. T. Taket, S. M. Howarth, and R. E. Burge, "A model for the imaging of urban areas by synthetic aperture radar," IEEE Trans. Geosci. Remote Sensing, vol. 29, pp. 432-443, May 1991.
  2. E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section.Norwood, MA: Artech House, 1985.
  3. A. van der Merwe, M. J. Gerry, L. C. Potter, and I. J. Gupta, "Feature estimation using a two-dimensional parametric model of radar scattering," in Proc. SPIE, Algorithms for Synthetic Aperture Radar Imaging IV, vol. 3070, pp. 322-333, 1997.
  4. J. B. Keller, "Diffraction by an aperture," J. Appl. Phys., vol. 28, pp. 426-444, 1957.
  5. N. D. Taket and R. E. Burge, "A physical optics version of the geometrical theory of diffraction," IEEE Trans. Antennas Propagat., vol. 39, pp. 719-731, June 1991.
  6. B. D. Carroll and R. E. Burge, "Experimental confirmation of recent results in GTD applied to a conducting quarter plate," J. Mod. Opt., vol. 39, pp. 1205-1220, 1992.
  7. R. G. Kouyoumjian and P. H. Pathak, "A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface," Proc. IEEE, vol. 62, pp. 1448-1461, Nov. 1974.
  8. S. W. Lee and G. A. Deschamps, "A uniform asymptotic theory of electromagnetic diffraction by a curved wedge," IEEE Trans. Antennas Propagat., vol. 24, pp. 25-34, Jan. 1976.
  9. C. W. Chuang and M. C. Liang, "A uniform asymptotic analysis of the diffraction by an edge in a curved screen," Radio Sci., vol. 23, pp. 781-790, 1988.
  10. M. C. Liang, C. W. Chuang, and P. H. Pathak, "A generalized uniform geometrical theory of diffraction ray solution for the diffraction by a wedge with convex faces," Radio Sci., vol. 31, pp. 679-691, 1996.
  11. R. J. Luebbers, "Propagation prediction for hilly terrain using GTD wedge diffraction," IEEE Trans. Antennas Propagat., vol. AP-32, pp. 951-955, Sept. 1984.
  12. B. J. Rubin, "General solution for propagation, radiation and scattering in arbitrary 3-D inhomogeneous structures," IEEE Antennas Propagat. Mag., vol. 34, pp. 17-25, Feb. 1992.
  13. D. H. Schaubert, D. R. Wilton, and A. W. Glisson, "A tetrahedral modeling method for electromagnetic scattering by arbitrarily shaped inhomogeneous dielectric bodies," IEEE Trans. Antennas Propagat., vol. AP-32, pp. 77-85, Jan. 1984.
  14. T. K. Sarkar, E. Arvas, and S. Ponnapalli, "Electromagnetic scattering from dielectric bodies," IEEE Trans. Antennas Propagat., vol. 37, pp. 673-676, May 1989.
  15. B. J. Rubin and S. Daijavad, "Radiation and scattering from structures involving finite-size dielectric regions," IEEE Trans. Antennas Propagat., vol. 38, pp. 1863-1873, Nov. 1990.
  16. A. W. Glisson, "An integral equation for electromagnetic scattering from homogeneous dielectric bodies," IEEE Trans. Antennas Propagat., vol. AP-32, pp. 173-175, Feb. 1984.
  17. K. Umashankar, A. Taflove, and S. M. Rao, "Electromagnetic scattering by arbitrary shaped three-dimensional homogeneous lossy dielectric objects," IEEE Trans. Antennas Propagat., vol. AP-34, pp. 758-766, June 1986.
  18. A. Taflove, K. R. Umashankar, and T. G. Jurgens, "Validation of FD-TD modeling of the radar cross section of three-dimensional structures spanning up to five wavelengths," IEEE Trans. Antennas Propagat., vol. AP-33, pp. 662-666, June 1985.
  19. K. T. Shlager and J. B. Schneider, "A selective survey of the finite-difference time-domain literature," IEEE Antennas Propagat. Mag., vol. 37, pp. 39-56, Aug. 1995.
  20. R. A. Ross, "Radar cross section of rectangular flat plates as a function of aspect angle," IEEE Trans. Antennas Propagat., vol. AP-14, pp. 329-335, May 1966.
  21. T. Griesser and C. A. Balanis, "Backscatter analysis of dihedral corner reflectors using physical optics and the physical theory of diffraction," IEEE Trans. Antennas Propagat., vol. AP-35, pp. 1137-1147, Oct. 1987.
  22. J. L. Volakis, W. T. Burnside, and L. Peters, "Electromagnetic scattering from appendages on a smooth surface," IEEE Trans. Antennas Propagat., vol. AP-33, pp. 736-743, July 1985.
  23. R. Tiberio, G. Pelosi, and G. Manara, "A uniform GTD formulation for the diffraction by a wedge with impedance faces," IEEE Trans. Antennas Propagat., vol. AP-33, pp. 867-873, Aug. 1985.
  24. T. Griesser and C. A. Balanis, "Reflections, diffractions, and surface waves for an interior impedance wedge of arbitrary angle," IEEE Trans. Antennas Propagat., vol. 37, pp. 927-935, July 1989.
  25. R. Tiberio and G. Pelosi, "High-frequency scattering from the edges of impedance discontinuities on a flat plane," IEEE Trans. Antennas Propagat., vol. AP-31, pp. 590-596, Apr. 1983.
  26. W. D. Burnside and K. W. Burgener, "High frequency scattering by a thin lossless dielectric slab," IEEE Trans. Antennas Propagat., vol. AP-31, pp. 104-110, Jan. 1983.
  27. P. M. Morse and H. Feshbach, Methods of Theoretical Physics.New York: McGraw-Hill, 1953, ch. 13.
  28. N. G. Van Kampen, "An asymptotic treatment of diffraction problems," Physica, vol. 14, pp. 575-589, 1949.
  29. M. Idemen, "Diffraction of an obliquely incident high-frequency wave by a cylindrical curved sheet," IEEE Trans. Antennas Propagat., vol. AP-34, pp. 181-187, Feb. 1986.
  30. G. D. Maliuzhinets, "Excitation, reflection and emission of surface waves from a wedge with given face impedances," Sov. Phys. Doklady, vol. 3, pp. 752-755, 1958.