A spectral integral method for layered media

Summary form only given. In order to solve layered-medium problems, various numerical methods have been developed. We are concerned with piecewise homogeneous objects embedded in a layered medium. As such; the surface integral equation (SIE) can be used to reduce the number of unknowns compared with the volume integral equation. The SIE is solved first with the method of moments (MoM) and then with the fast multipole method (FMM) to calculate the electromagnetic fields scattered from a homogeneous scatter with arbitrary geometry in free space. J. Liu and Q. H. Liu (see IEEE Micro. and Wire. Comp. Lett., vol.14, no.3, p.97-9, 2004) developed a spectral integral method (SIM) as an alternative way of solving the surface integral equation more efficiently than MoM for arbitrarily-shaped smooth dielectric cylinders in free space. We extend this method to arbitrarily-shaped smooth perfect electrical conductor (PEC) and dielectric cylinders in a multilayer medium. We have demonstrated the spectral accuracy of the method and the reduced computational cost from that of the MoM. This method can also be extended to three dimensions.