• Method of Moments
• Finite Element
• Aperture Antennas
• Mode Matching

In this work novels hybrid numerical techniques are proposed for the efficient analysis of complex radiating devices; attention is focused both in the single element and arrays of aperture antennas. The presented approaches are based on the joint application of different numerical techniques tailored to the different regions of the radiating structures. The mode matching technique is adopted for the scattering characterization of the waveguide problem in conjunction with a two dimensional finite element method for the modal analysis of unconventional shaped waveguide cross-sections. The outer free space problem is solved by employing the method of moments for the solution of the boundary integral-differential equations. To reduce both the solve-time as well as the number of unknowns involved in the method of moment solution a characteristic basis functions approach in conjunction with a fast matrix generation technique is presented for the analysis of large arrays. The proposed novel approaches furnish an accurate, efficient and flexible simulation tools for the design of aperture antennas.