A hybrid algorithm for electromagnetic problems involving fine structures based on FDTD and FETD with unstable modes removing

We put forward a novel hybrid algorithm, based on merging finite-element time-domain (FETD) with finite-difference time-domain (FDTD) methods, to solve electromagnetic problems involving fine structures. The FETD method with unstable modes removing (UMR-FETD) is employed in regions relating to fine structures, while the FDTD method is adopted in the other regions. The suggested hybrid approach reduces the dimension of the system matrix for the UMR-FETD method, thus decreasing the consumption of computing resources. Besides, the hybrid algorithm makes it possible to adopt a uniform and large time step in the whole computational domain, thus improving computational efficiency. Numerical results confirm the good performance of the proposed hybrid algorithm to solve electromagnetic problems involving fine structures.