Use of the perturbation technique for implementation of surface impedance boundary conditions for the FDTD method

A nem approach to implement a surface impedance boundary condition (SIBC) f or the FDTD method is proposed. The explicit FDTD formulation for the bound ary cell closest to the surface of conducting body is obtained using the pe rturbation technique in the small parameter proportional to the ratio of th e values of the electric field at the opposite sides of the cell. The condi tion of applicability of the technique is obtained, It is shown that an FDT D code where the PEG-condition has been already implemented can be easily u pgraded using the proposed technique to take into account properties of the conducting medium and improve accuracy of the computation, Numerical examp les are included to illustrate the theory.