A Conformal Surface-Impedance Boundary Condition for the Modeling of Curved Lossy Surfaces in 3-D FIT/FDTD Techniques

A conformal first-order surface-impedance boundary condition (SIBC) for the modeling of lossy curved surfaces in a Cartesian grid is presented for the finite-integration technique (FIT). Alternatively, the model can be derived using the contour-path formulation of the finite-difference time domain (FDTD) method. The SIBC is based on a lumped-element representation of the impedance combined with a conformal modeling scheme.