An improved leapfrog ADI-FDTD method for computing surface current distributions of complex structures in the presence of an intentional electromagnetic pulse (IEMP)

An improved leapfrog alternating-direction (ADI) finite-difference time-domain (FDTD) method is provided for computing surface current distributions of some complex PEC and dielectric composite structures illuminated by an intentional electromagnetic pulse (IEMP). The techniques for introducing into an incident plane wave, updating the iteration equations at the connecting boundaries according to the total and scattered fields, and computing the surface currents are all implemented into the leapfrog ADI-FDTD algorithm. Some numerical results are given to show the predicted surface current distribution of an aircraft model illuminated by an IEMP with different incident directions and polarizations, and good agreement is obtained in comparison with those of the commercial software CST and FEKO.