Transient Analysis for Electromagnetic Scattering by Dielectric Objects Based on PMCHWT Equations

Transient electromagnetic scattering by dielectric objects is formulated through time-domain Poggio-Miller-Chang-Harrington-Wu-Tsai (TDPMCHWT) equations which are usually solved by combining the method of moments (MoM) in space domain and march-on-in-time (MoT) scheme in time domain. The space-domain MoM requires two basis functions to represent the electric and magnetic current densities, respectively, and its implementation may not be convenient. Also, the MoT scheme has a well-known late-time instability problem which will aggravate in the surface integral equations of dielectric media. We present a different approach to solve the TDPMCHWT equations by incorporating the Nystrom method in space domain and a Galerkin method with Laguerre basis and testing functions in time domain. The approach presents certain merits compared with the conventional method as demonstrated by a numerical example.