Parallel FEM for 3D Electromagnetic Scattering via Sender-Based FETI-DP and Optimized Subdomain Decomposition

This paper proposes a parallel finite element analysis framework for solving large-scale three-dimensional electromagnetic scattering problems in the high-frequency regime. The proposed method is based on the dual-primal finite element tearing and interconnecting (FETI-DP) algorithm and adopts a sender-based communication scheme in which each subdomain autonomously transmits its computed values, as opposed to the conventional receiver-based communication scheme. This reduces communication bottlenecks and ensures stable convergence of the biconjugate gradient stabilized method (BiCG-STAB) iterative solver. In addition, a one-to-many subdomain mapping strategy is implemented, allowing a single message passing interface (MPI) processor to manage multiple subdomains. This enables superior scalability and memory efficiency even in environments with limited parallel resources and allows for the derivation of the optimal number of subdomains based on total floating-point operations (total FLOPs). Simulations are conducted on dielectric only and dielectric-coated structures, validating numerical accuracy through comparison with HFSS and confirming the scalability and efficiency of the proposed framework across various problem sizes.