A Provably Stable FDTD Subgridding Technique for Transient Electromagnetic Analysis

A provably stable subgridding finite-difference time-domain (FDTD) method is proposed to accurately and efficiently solve transient electromagnetic problems with multi-scale structures. By carefully adding more field components on the boundaries of computational domain, several summationby-parts (SBP) operators are constructed to approximate the Maxwell’s equations. Through using the simultaneous approximation terms (SAT) technique, boundary conditions are weakly enforced. The proposed SBP-SAT FDTD subgridding method is not only accurate and efficient, but also can simply model complex structures in the practical simulations. Numerical results verify its accuracy, efficiency and flexibility.