A Mortar Element Method for the Analysis of Electromagnetic Passive Devices

The thesis consists of two blocks. The first and main block concerns the application of multi-domain spectral methods to the analysis of electromagnetic guiding structures. A general scattering formulation for vector differential problems is developed. The boundary-value problems are discretized using basis functions synthesized according to the mortar-element method. An analysis technique of the scattering generated by skew-incident plane waves on 2-D dielectric periodic structures based on this idea is proposed; the boundary-value problem describing these devices is given by the system of two coupled Helmholtz equations, therefore it exhibits a vector nature. Then, a technique aimed at analyzing axisymmetric structures using the same concept has been developed; in this case, the boundary-value problem arises from the transversalization of Maxwell’s equations written in cylindrical coordinates with respect to the angular coordinate. Half of the second block concerns the design of a low-frequency Vivaldi antenna in the framework of the Sardinia Array Demonstrator project. This antenna has been realized and preliminarily characterized with a prototypical measurement system developed by CNR-IEIIT. The second half of this block is focused on the development of a boundary-integral equation method aimed at analyzing dielectric lens antennas. A preliminary version of this code has been implemented and compared with commercial simulators. This activity has been performed in the THz Sensing Group of TU-Delft, Delft, Netherlands.