Fast calculation of wide band RCS pattern of dielectric cylinders using the FDTD method and the Pade interpolation technique

The mono-static RCS pattern of an arbitrarily shaped two-dimensional (2-D) dielectric cylinder is calculated by near-far field transformation, when selected method is the FDTD method. Because achieving the time domain signal of far field is very difficult, it is necessary to perform a lager of near-far field transformation when the wide band RCS is computed. In this article, the Pade interpolation technique is employed to obtain frequency domain results with satisfactory accuracy. By use of some RCS results, which are obtained using FDTD method, the rational function of RCS pattern can be achieved. Then the wide band RCS pattern can be calculated by use of the rational function. This reduces the computation time significantly compared with the conventional FDTD algorithm. The wide band RCS results computed by use of the Pade interpolation technique are compared with the conventional FDTD results. A good agreement is observed.