Applications of the direct domain decomposition based on cylindrical ports in the hybrid Finite Element/Modal Analysis method

In this work, it will be shown some interesting capabilities of a direct domain decomposition methodology, based on the use of the hybrid finite element/modal analysis (FE/MA), which takes advantage of the addition theorems for cylindrical waves. These theorems allow to perform analytical rotations and translations of domains in the whole structure, avoiding recalculations with the FE/MA method. Specifically, it will be used to place via holes between patch antennas on a continuous substrate, in order to prevent mutual coupling through the substrate. It will also be shown how this methodology can be applied to the fast analysis of radial line slot antennas, where each slot is considered as a subdomain defined by a cylindrical port and a hemispherical port; and to the analysis of groove gap waveguides, where each quadrangular post is characterized by a cylindrical port.