LOD-FDTD Simulation to Estimate Shielding Effectiveness of Periodic Structures

A three-dimensional unconditionally stable locally-one-dimensional FDTD (LOD-FDTD) method is developed and is extended to analyze periodic structures. The number of equations to be computed in LOD-FDTD is the same as that with the three-dimensional alternating-direction implicit FDTD (ADI-FDTD) but with reduced arithmetic operations. For periodic LOD-FDTD method, the cyclic matrix lead by the periodic boundary condition can be converted into two auxiliary linear systems that can be solved using the tridiagonal matrix solver. Numerical simulations to calculate the shielding effectiveness of a wire mesh screen are compared with those using the conventional FDTD and ADI-FDTD method, which further demonstrate the effectiveness of this periodic LOD-FDTD method.