Signal integrity analysis of modified interconnects using graded FDTD method

At higher clock frequencies signal integrity effects play major role in interconnect design. In this paper modified coplanar structure is introduced as an interconnect which reduces coupling to adjacent traces. Graded FDTD method is applied for analyzing fields in the region of edges and in between conducting plane and ground plane of the modified coplanar structure and it is shown that graded FDTD method takes lesser simulation time as compared to ordinary FDTD method. Finite difference Laplace interpolation scheme is applied on the graded region to get fields in more detail in the desired region of interest. The problem domain is subdivided in to two regions called fine and coarse regions, the cell size in the finer region is reduced to twice than that of coarse region to analyze the fields in more detail. Boundary conditions are applied (absorbing boundary condition and perfectly matched layer condition) and fields are analyzed. The results are compared with ordinary mesh with out applying any grading.