rods have same parameters with previous numerical examples. Example of the total electric field profile with frequency f = 4.0GHz by CIP method is shown in Fig.5, where parameters were set as follows; space discretization Δ = 0.5mm, time step Δt = 2.5 × 10−13sec, total cell numbers 648 × 659, cells on diameter of the cylinder 10, respectively.
In Fig.7, maximum electric field profile at output after filtering is shown. Two pairs of rods were inserted simultaneously in each output waveguide for filtering different frequencies. Length of the cavity is 2.5P and another one is 3.0P, respectively, where P is lattice period. As expected, frequencies with half-wavelength-along-waveguide which corresponding to each cavity length are filtered and obtained in each port