Browsing by Subject "Combined-field integral equation"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    On the accuracy of MFIE and CFIE in the solution of large electromagnetic scattering problems
    (ESA Publications, 2006) Ergül, Özgür; Gürel, Levent
    We present the linear-linear (LL) basis functions to improve the accuracy of the magnetic-field integral equation (MFIE) and the combined-field integral equation (CFIE) for three-dimensional electromagnetic scattering problems involving large scatterers. MFIE and CFIE with the conventional Rao-Wilton-Glisson (RWG) basis functions are significantly inaccurate even for large and smooth geometries, such as a sphere, compared to the solutions by the electric-field integral equation (EFIE). By using the LL functions, the accuracy of MFIE and CFIE can be improved to the levels of EFIE without increasing the computational requirements and with only minor modifications in the existing codes based on the RWG functions.
  • Thumbnail Image
    ItemOpen Access
    Parallel-MLFMA solution of CFIE discretized with tens of millions of unknowns
    (Institution of Engineering and Technology, 2007) Ergül, Özgür; Gürel, Levent
    We consider the solution of large scattering problems in electromagnetics involving three-dimensional arbitrary geometries with closed surfaces. The problems are formulated accurately with the combined-field integral equation and the resulting dense matrix equations are solved iteratively by employing the multilevel fast multipole algorithm (MLFMA). With an efficient parallelization of MLFMA on relatively inexpensive computing platforms using distributed-memory architectures, we easily solve large-scale problems that are discretized with tens of millions of unknowns. Accuracy of the solutions is demonstrated on scattering problems involving spheres of various sizes, including a sphere of radius 110 λ discretized with 41,883,638 unknowns, which is the largest integral-equation problem ever solved, to the best of our knowledge. In addition to canonical problems, we also present the solution of real-life problems involving complicated targets with large dimensions.