SBR for Near-Field Scattering of PEC Objects Under Far-Field Antenna Radiation

In this paper, the scattered near-fields from electrically large complex PEC objects illuminated by far-field antenna sources are calculated by shooting and bouncing ray (SBR) method. In order obtain accurate near-field scattering results, an physical-optics (PO) near-field integral representation is proposed and reduced to closed form expressions to improve computing efficiency by applying locally expanded Green function approximations. By introducing the proposed PO near-field integral expressions, SBR can be used to analyze near-field scattering from a PEC target under far-field antenna sources radiation. The method is applicable to analyze the near-field scattering problem under arbitrary far-field source incident. Numerical example is presented to demonstrate the efficiency and accuracy of the proposed method.