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IEEE Transactions on Antennas and Propagation
Volume 47 Number 4, April 1999

Table of Contents for this issue

Complete paper in PDF format

A Novel Efficient Algorithm for Scattering from a Complex BOR Using Mixed Finite Elements and Cylindrical PML

Andrew D. Greenwood, Member, IEEE, and Jian-Ming Jin, Senior Member, IEEE

Page 620.

Abstract:

An efficient finite-element method (FEM) is developed to compute scattering from a complex body of revolution (BOR). The BOR is composed of perfect conductor and impedance surfaces and arbitrary inhomogeneous materials. The method uses edge-based vector basis functions to expand the transverse field components and node-based scalar basis functions to expand the angular component. The use of vector basis functions eliminates the problem of spurious solutions suffered by other three component FEM formulations. The FEM mesh is truncated with a perfectly matched layer (PML) in cylindrical coordinates. The use of PML in cylindrical coordinates avoids the wasted computation which results from a spherical mesh boundary with an elongated scatterer. The FEM equations are solved by ordering the unknowns with a reverse Cuthill-McKee algorithm and applying a banded-matrix solution algorithm. The method is capable of handling large, realistic radar targets, and good agreement with measured results is achieved for benchmark targets.

References

  1. M. G. Andreasen, "Scattering from bodies of revolution," IEEE Trans. Antennas Propagat., vol. AP-13, pp. 303-310, Mar. 1965.
  2. J. R. Mautz and R. F. Harrington, "Electromagnetic scattering from a homogeneous body of revolution," Arch. Elektron. Ubertragungstech., vol. 33, pp. 71-80, 1979.
  3. L. N. Medgyesi-Mitschang and J. M. Putnam, "Electromagnetic scattering from axially inhomogeneous bodies of revolution," IEEE Trans. Antennas Propgat., vol. AP-32, pp. 797-806, Aug. 1984.
  4. R. Gordon and R. Mittra, "PDE techniques for solving the problem of radar scattering by a body of revolution," Electromagn., vol. 10, pp. 163-174, 1990.
  5. M. A. Morgan, S. K. Chang, and K. K. Mei, "Coupled azimuth potentials for electromagnetic field problems in inhomogeneous axially symmetric media," IEEE Trans. Antennas Propgat., vol. AP-25, pp. 413-417, May 1977.
  6. M. A. Morgan and K. K. Mei, "Finite-element computation of scattering by inhomogeneous penetrable bodies of revolution," IEEE Trans. Antennas Propgat., vol. AP-27, pp. 202-214, Mar. 1979.
  7. A. Khebir, J. D'Angelo, and J. Joseph, "A new finite element formulation for RF scattering by complex bodies of revolution," IEEE Trans. Antennas Propgat., vol. 41, pp. 534-541, May 1993.
  8. J. F. Lee, G. Wilkins, and R. Mittra, "Finite-element analysis of an axisymmetric cavity resonator using a hybrid edge element technique," IEEE Trans. Microwave Theory Tech., vol. 41, pp. 1981-1987, Nov. 1993.
  9. D. J. Hoppe, L. Epp, and J. F. Lee, "A hybrid symmetric FEM/MOM formulation applied to scattering by inhomogeneous bodies of revolution," IEEE Trans. Antennas Propgat., vol. 42, pp. 798-805, June 1994.
  10. W. C. Chew, J. M. Jin, and E. Michielssen, "Complex coordinate stretching as a generalized absorbing boundary condition," in 13th Annu. Rev. Progress Appl. Comput. Electromagn., Monterey, CA, vol. II, pp. 909-914, Mar. 1997.
  11. F. L. Teixeira and W. C. Chew, "Systematic derivation of anisotropic PML absorbing media in cylindrical and spherical coordinates," IEEE Microwave Guided Wave Lett., vol. 7, pp. 371-373, Nov. 1997.
  12. J. Maloney, M. Kesler, and G. Smith, "Generalization of PML to cylindrical geometries," in 13th Annu. Rev. Progress Appl. Computa. Electromagn., Monterey, CA, vol. II, pp. 900-908, Mar. 1997.
  13. J. M. Jin, The Finite Element Method in Electromagnetics.New York: Wiley, 1993.
  14. M. F. Wong, M. Prak, and V. F. Hanna, "Axisymmetric edge-based finite element formulation for bodies of revolution: Application to dielectric resonators," in IEEE MTT-S Dig., pp. 285-288, May 1995.
  15. A. George and J. W. Liu, Computer Solution of Large Sparse Positive Definite Systems.Englewood Cliffs, NJ: Prentice-Hall, 1981.
  16. A. C. Woo, H. T. G. Wang, M. J. Schuh, and M. L. Sanders, "Benchmark radar targets for the validation of computational electromagnetics programs," IEEE Antennas Propagat. Mag., vol. 35, pp. 84-89, Feb. 1993.
  17. P. Rozenfeld, "The electromagnetic theory of three-dimensional inhomogeneous lenses," IEEE Trans. Antennas Propgat., vol. 24, pp. 365-370, May 1976.