On the Behavior of the LOD-FDTD Method at Dielectric Interfaces

Abstract

The electric field computed by the locally one dimensional finitedifference timedomain (LODFDTD) method at dielectric interfaces is investigated. To this end, two compre hensive problems are considered, namely a dielectric step in a rectangular waveguide and a dielectricloaded metallic cavity. We found that, in both problems, the electric field patterns exhibit an unexpected phase shift at the dielectric interface. By contrast, the alternatingdirection implicit (ADI)FDTD method does not present this unphysical behavior.