Transient scattering using finite elements with curved absorbing boundaries

We present a time-domain solution to 2D TM/TE electromagnetic scattering problems using the finite element method. We implement Barry-Bielak-MacCamy (BBM) time and space local absorbing conditions (proposed in 1988) on a curved convex truncated domain boundary. The BBM boundary conditions, which encompass the popular Bayliss-Turkle mode annihilating boundary conditions and Kriegsmann on-surface boundary conditions, yield symmetric second order systems, which are then integrated using Newmark's schemes. Numerical examples are provided and validated against published data. The method can be in principle extended to 3D transient scattering.