volume | PIER Journals

Abstract

An iterative solution scheme based on the magnetic field integral equation (MFIE) to compute electromagnetic scattering for arbitrary, perfect electrically conducting (PEC) objects is topic of this contribution. The method uses simple and efficient approaches for the computation of surface current interactions which are typically found in the well-known iterative physical optics (IPO) technique. However, the proposed method is not asymptotic, since no physical optics (PO) concepts are utilized. Furthermore, a least squares correction method is introduced, which is applied not on the complete current vector, but on individual groups of currents. This helps to quickly reduce the residual error and to improve convergence. The result is a simple method which is capable to improve the simulation results obtained by pure asymptotic methods such as PO or shooting and bouncing rays (SBR). The method can be regarded as a simplified iterative method of moments (MoM) technique. Numerical examples show that the proposed approach is advantageous e.g. in problem cases where the neglect of diffraction effects or currents in shadow regions would cause large errors. It also provides an improved prediction of the peak scattering contributions.

1. Jakobus, U. and F. Landstorfer, "Improved PO-MM hybrid formulation for scattering from three-dimensional perfectly conducting bodies of arbitrary shape," IEEE Trans. Antennas Propagat., Vol. 43, No. 2, 162-169, 1995.
doi:10.1109/8.366378 Google Scholar

2. Jakobus, U. and F. Landstorfer, "Improvement of the PO-MoM hybrid method by accounting for effects of perfectly conducting wedges," IEEE Trans. Antennas Propagat., Vol. 43, No. 10, 1123-1129, 1995.
doi:10.1109/8.467649 Google Scholar

3. Jakobus, U. and F. Landstorfer, "Application of Fock currents for curved convex surfaces within the framework of a current-based hybrid method," Third International Conference on Computation in Electromagnetics, 415-420, Bath, UK, Apr. 1996.
doi:10.1049/cp:19960223 Google Scholar

4. Hodges, R. and Y. Rahmat-Samii, "An iterative current-based hybrid method for complex structure," IEEE Trans. Antennas Propagat., Vol. 45, No. 2, 265-276, 1997.
doi:10.1109/8.560345 Google Scholar

5. Tasic, M. and B. Kolundzija, "Efficient analysis of large scatterers by physical optics driven method of moments," IEEE Trans. Antennas Propagat., Vol. 59, No. 8, 2905-2915, 2011.
doi:10.1109/TAP.2011.2158785 Google Scholar

6. Thiele, G. and T. Newhouse, "A hybrid technique for combining moment methods with the geometrical theory of diffraction," IEEE Trans. Antennas Propagat., Vol. 23, No. 1, 62-69, 1975.
doi:10.1109/TAP.1975.1141004 Google Scholar

7. Tzoulis, A. and T. Eibert, "A hybrid FEBI-MLFMM-UTD method for numerical solutions of electromagnetic problems including arbitrarily shaped and electrically large objects," IEEE Trans. Antennas Propagat., Vol. 53, No. 10, 3358-3366, 2005.
doi:10.1109/TAP.2005.856348 Google Scholar

8. Kaye, M., P. Murthy, and G. Thiele, "An iterative method for solving scattering problems," IEEE Trans. Antennas Propagat., Vol. 33, No. 11, 1272-1279, 1985.
doi:10.1109/TAP.1985.1143510 Google Scholar

9. Murthy, P., K. Hill, and G. Thiele, "A hybrid-iterative method for scattering problems," IEEE Trans. Antennas Propagat., Vol. 34, No. 10, 1173-1180, 1986.
doi:10.1109/TAP.1986.1143738 Google Scholar

10. Obelleiro, F., J. Rodriguez, and R. Burkholder, "An iterative physical optics approach for analyzing the electromagnetic scattering by large open-ended cavities," IEEE Trans. Antennas Propagat., Vol. 43, No. 4, 356-361, 1995.
doi:10.1109/8.376032 Google Scholar

11. Burkholder, R., "A fast and rapidly convergent iterative physical optics algorithm for computing the RCS of open-ended cavities," Appl. Computational Electromagn. Soc. J., Vol. 16, No. 1, 53-60, 2001. Google Scholar

12. Lu, C. and W. Chew, "Fast far-field approximation for calculating the RCS of large objects," Microwave Opt. Tech. Letters, Vol. 8, No. 5, 238-241, 1995.
doi:10.1002/mop.4650080506 Google Scholar

13. Gibson, W., The Method of Moments in Electromagnetics, Chapman & Hall/CRC, Boca Raton, 2008.

14. Kang, G., J. Song, W. Chew, K. Donepudi, and J. Jin, "A novel grid-robust higher order vector basis function for the method of moments," IEEE Trans. Antennas Propagat., Vol. 49, No. 6, 908-915, 2001.
doi:10.1109/8.931148 Google Scholar

15. Burkholder, R. and T. Lundin, "Forward-backward iterative physical optics algorithm for computing the RCS of open-ended cavities," IEEE Trans. Antennas Propagat., Vol. 53, No. 2, 793-799, 2005.
doi:10.1109/TAP.2004.841317 Google Scholar

16., https://www.cst.com/Products/CSTMWS.
doi:10.1109/TAP.2004.841317 Google Scholar

17. Woo, A., H. Wang, M. Schuh, and M. Sanders, "Benchmark radar targets for the validation of computational electromagnetics programs," IEEE Antennas Propagat. Mag., Vol. 35, No. 1, 84-89, 1993.
doi:10.1109/74.210840 Google Scholar

Mr. Robert Brem

Dr. Thomas F. Eibert