Electromagnetic modeling of 3D PEC objects in a half-space environment

In this paper, efficient methods are discussed to calculate radiation or scattering from three-dimensional perfectly electrically conducting objects located in the half-space environment. Firstly, optimization for impedance-matrix-filling is accomplished to avoid repeated evaluation of Green´s functions or Sommerfeld integrals. Then the appropriate evaluation methods for Sommerfeld integrals, such as the method of integration along folded Sommerfeld integral path (FSIP), the method of integration along steepest descent path (SDP), the discrete complex image method (DCIM) and so on, are applied to the different regions with different observation-to-source distance. By these methods, the Sommerfeld integrals can be calculated accurately and fast. Finally, tabulation and interpolation for Green´s functions are used to further accelerate the process of impedance-matrix-filling. Some examples are presented for validation. The numerical results have shown that these methods can be used to model the radiation and scattering from complex objects located in a half-space environment accurately and efficiently.