A piecewise integration conformal method for electromagnetic scattering problems

A piecewise integration conformal finite difference time domain(PI-CFDTD)method is presented and applied for solving the electromagnetic scattering problems. The electric field component along the contour segment is expressed by the interpolation of the nearest ones. To compute electric-field contour-integral value more accurately, the piecewise-integration method is used instead of the common integration. Therefore, the staircasing errors can be reduced significantly. The electric-field contour-integral formula is derived for two kinds of deformed cells, respectively. Furthermore, the numerical stability is discussed. Finally, a metal square plate and a metal circular plate are simulated as examples. The results are compared with those of the conventional FDTD method CFDTD method and the MoM. It is found that the PI-CFDTD method is more accurate than the conventional CFDTD method.