An efficient boundary condition based on surface impedance concept in FDTD simulations

Surface impedance boundary condition (SIBC) is a potential way to improve the efficiency of finite difference time domain (FDTD) method. In this paper, we propose an efficient SIBC, the PEC backed SIBC (PEC-SIBC). We first derived the updating equations of PEC-SIBC for 1D. The updating equations for 2D and 3D can be derived following the same procedure. Later, we verified the accuracy of PEC-SIBC and analyzed its calculation complexity with a 2D examples. Even though the calculation amount for PEC-SIBC is a little larger than the traditional SIBC, it is better for improving the efficiency of implementing the FDTD method.