New kind of orthogonal grid generation algorithm in FDTD

Aiming at the grid generation problem in FDTD, a new kind of orthogonal grid generation algorithm based on polar angle judgment is provided. This algorithm cuts the object of characteristic of electromagnetic scattering which needs to be researched into a set of star polygons (polyhedrons) and judges the polar angle range of grid central point of each star polygon (polyhedron). Thus, based on the judgment of the grid central point, the inner grids are remained to generate the orthogonal grids. This algorithm can avoid the problem of singularity in the Kalay orthogonal grid generation algorithm and is better than Kalay´s algorithm in computing complexity.