Implementation of the Second-Order ABC in the FETI-DPEM Method for 3D EM Problems

The electromagnetic dual-primal finite element tearing and interconnecting (FETI-DPEM) method, originally equipped with the first-order absorbing boundary condition (ABC), is combined with the second-order ABC implemented using auxiliary variables to enhance the accuracy of electromagnetic scattering and radiation simulations. When the second-order ABC surface is partitioned by domain decomposition, it is necessary to enforce an extra continuity condition on the auxiliary variables representing a continuous surface divergence for the electric field at the junctions of the subdomain interfaces and the truncation surface. A simple approach to enforce such a continuity is proposed without altering the overall framework of the FETI-DPEM method. Numerical examples are provided to demonstrate the accuracy improvement due to the use of the second-order ABC.