Development of a Novel FDTD (2, 4)-Compatible Conformal Scheme for Electromagnetic Computations of Complex Curved PEC Objects

We present a modified fourth-order finite-difference time-domain [FDTD (2, 4)] conformal scheme for accurately computing electromagnetic characteristics of some complex three-dimensional (3D) perfectly conducting (PEC) objects. It has higher accuracy and efficiency than those of conventional FDTD and FDTD (2, 4) methods, as coarse meshes are employed with staircase errors reduced effectively during its implementation. Two integration loops of the Faraday's law are used for updating magnetic field components, while the updating equations of electric field ones are the same as those in the normal FDTD method. A rigorous analysis of its global stability, based on the conventional high-order FDTD stability criterion and the Fourier method, is also performed. In order to obtain stable and accurate numerical results, a user-defined geometric precision technique, which gives a criterion for determining the time step, is employed for our computations. It is numerically demonstrated that using our proposed FDTD (2, 4)-compatible conformal scheme, high accuracy and low dispersion errors can be achieved for fast predicting radar cross sections as well as induced current distribution of some complex 3-D structures.