Accuracy of point source models with coincident phase centers in a cubic FDTD grid for arbitrary source orientation

Standard point source modeling in the Finite Difference Time Domain (FDTD) method has been accomplished by centering the source at the appropriate electric or magnetic field node in a given Yee cell. While this methodology is adequate for many applications, it produces a source whose Cartesian oriented field components have slightly different phase centers, which yields a visible propagation delay between these components. For phase sensitive applications, more accurate consideration of the source phase center may be required. In this study, we introduce a means of producing point sources with coincident phase centers. We will show that these sources provide good accuracy at close distances to the phase center while outperforming the standard sources in the near field when an arbitrary direction of the point source moment is required.