Modelling complex structures by combining the FE, FDTD and BIE techniques

The finite element method, the finite-difference time-domain algorithm and the boundary integral equation technique are combined into one hybrid approach to model complex three-dimensional structures. After decomposition of the simulation geometry, the 3D boundary integral technique is used for homogeneous bounded and unbounded regions. Each inhomogeneous subregion is either described at one frequency by a finite element method, or an interaction matrix calculated at multiple frequencies using FDTD. By expressing continuity of the tangential fields at all the interfaces between the subregions, the interaction matrices and the excitations vectors resulting from the three different techniques are assembled into one global matrix equation.