Time-Domain Analysis of Transient Electromagnetic Scattering From Dielectric Objects Based on Electric Field Integral Equations

Time-domain analysis for transient electromagnetic scattering from dielectric objects is formulated through time-domain electric field integral equations (TDEFIEs). The TDEFIEs are usually solved by combining the method of moments (MoM) in space domain and march-on-in-time (MoT) scheme in time domain. In the space-domain MoM, the electric current density is represented with the Rao-WiltonGlisson (RWG) basis function, while the magnetic current density is expanded by the n̂×RWG basis function, which may not be good, since it is not divergenceor curl-conforming. Also, the MoT scheme has a well-known late-time instability problem, which will aggravate in timedomain surface integral equations with penetrable media. We present a different strategy to solve the TDEFIEs by using the Nyström method to discretize the space domain and using the Galerkin method with Laguerre basis and testing functions to discretize the time domain. The proposed method can fully overcome the problems of conventional methods as the presented numerical examples have demonstrated.