Analysis of Scattering from Composite Conducting and Dielectric Targets Using the Precorrected-fft Algorithm

|A precorrected-FFT algorithm is presented for the calculation of electromagnetic scattering from conducting objects coated with lossy materials. The problem is formulated using an EFIE-PMCHW formulation, which employs the electric ­ eld integral equation (EFIE) for conducting objects and the PMCHW formulation for dielectric objects. The integral equations are then discretized by the method of moments (MoM), in which the conducting and dielectric surfaces are represented by triangular patches and the unknown equivalent electric and magnetic currents are expanded using the RWG basis functions. The resultant matrix equation is solved iteratively and the precorrected-FFT method is used to speed up the matrix-vector products in iterations as well as to reduce the memory requirement. Numerical examples are presented to validate the implementation and to demonstrate the accuracy of the method.