Analysis of sharp metal edges at 45 degrees to the FDTD grid

New finite-difference time-domain (FDTD) update equations for sharp metal e dges are presented. The edge is assumed to be diagonal to the Yee cell face s. Derived using the contour-path method, the new equations properly model the singular field near the edge even with a relatively coarse grid. A dram atic improvement in computed accuracy was observed when a stripline with tw o sharp edges was analyzed using the new equations instead of standard FDTD techniques; The new equations are found to be stable even with the maximum allowed time step, easy to implement, and do not increase computer memory and time requirements.