Simulation of locally inhomogeneous multilayer planar structure by hybrid method

A new hybrid finite-difference time-domain and mixed-potential integral equation method (hybrid FDTD-MPIE) is developed for the modeling of multilayer planar structures with locally inhomogeneous objects. By using the equivalence principle, the original problem can be decomposed into external and internal problems. The FDTD method is applied to solve the internal problem, which contains the locally inhomogeneous dielectric objects. Conversely, the frequency domain MPIE method is employed to address the external problem of the global multilayered planar structure. The FDTD model and the MPIE model are coupled together by enforcing the continuity of tangential fields on the equivalent surface. Both the direct and iterative method are demonstrated In this work to solve the integral-differential problem. In addition, the DCIM (discrete complex image) method is applied to improve the computational efficiency. Numerical results are presented to validate the proposed hybrid FDTD-MPIE method.