Numerical Analysis for an Improved ADI-FDTD Method

The numerical performance of an improved alternating direction implicit finite-difference time-domain (ADI-FDTD) method is studied in this letter. Theoretical analysis shows that this method is unconditionally stable and has low splitting error. Compared with the regular ADI-FDTD method, this method is a better splitting formulation for the Crank-Nicolson FDTD method.