On the applicability of OSRC method to homogeneous scatterers

The author investigates the application of radiation boundary conditions to two-dimensional scattering by a homogeneous penetrable cylinder. The second-order radiation boundary operator proposed by G.A. Kriegsmann et al. (1987) is applied on a conformal outer boundary enclosing the object. By taking the specific case of a lossless circular cylinder for which the exact solution exists it is shown that the on-surface radiation condition (OSRC) method does not necessarily yield accurate results for all values of material constants. Highly erroneous results are produced for certain values of permittivity and permeability, while acceptable results can be obtained for others. The author suggests that the cause of these erroneous results is related directly to the error in the reactive portion of the complex scattered power. However, as the outer boundary of the radiation condition recedes away from the object contour, the error is shown to diminish. Numerical results are presented for the bistatic echo width for both transverse electric (TE) and transverse magnetic (TM) polarizations.<
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