Reduction of Unphysical Wave Reflection Arising From Space-Time Finite Integration Method

Several 3-D and 4-D space-time grids are compared for electromagnetic wave computations using the space-time finite integration (FI) method. To suppress unphysical wave reflections without incurring numerical instability, the constitutive relation is corrected while retaining the symmetric of impedance matrix. Eigenvalue analysis confirms the stability of the 3-D space-time FI schemes, where an asymmetric impedance matrix could cause late instability. A 4-D space-time FI scheme is also improved by symmetric corrections.