Analysis of scattering from arbitrarily shaped 3-D conducting/dielectric composite objects using a combined field integral equation

In this paper, we present a new formulation for the analysis of electromagnetic scattering from arbitrarily shaped three-dimensional (3-D) perfectly conducting and piecewise homogeneous dielectric composite body. The formulation treated here is the combined field integral equation (CFIE). The conducting/dielectric structure is approximated by planar triangular patches, which have the ability to conform to any geometrical surface. The surface covering the conducting body is replaced by an equivalent surface electric current and the surface of the dielectric by equivalent electric and magnetic currents. The all surface currents are approximated in terms of RWG (Rao, Wilton, Glisson) functions. The objective of this paper is to illustrate that the CFIE is a valid methodology in removing defects, which occur at a frequency corresponding to an internal resonance of the structure. Numerical results are presented and compared for composite scatterers with solutions obtained using other formulations.