Treatment of metal laminas with sharp edges at arbitrary angles to the FDTD grid using MAMPs

Previous enhancements to the FDTD method have facilitated the analysis of structures containing sharp metal edges, such as microstrip, when the edges are aligned with the mesh and also of smooth, arbitrarily curved metal objects. So far, however, there has been little work on the often encountered situation of thin metal patches which are orientated at an angle to the mesh other than for the special case of diagonal orientation. In this paper, the general case is examined and it is shown that the use of modified assigned material parameters (MAMPs) is an effective way of efficiently and accurately treating this problem.