“…In these method the discrete techniques such as finite element method (FEM) [13][14][15], finite-difference time domain method (FDTD) [16][17][18] or frequency domain (FDFD) [19] methods and method of moments (MoM) [18,20,21] are used in limited region surrounding the analyzed structure. In the outer region the fields are combined with analytical solution of the problem using e.g., integral equation technique [15,17] for open structures or general scattering matrix (GSM) approach for closed problems [13,20,21]. As a result, the hybrid techniques allows one to achieve higher flexibility, increase the accuracy and reduce the numerical complexity of the analysis.…”