Hybrid Method Analysis of Unshielded Guiding Structures

A combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first region and fields outside are expressed by analytical functions. As a last step propagation coefficients are obtained with the use of global roots and poles finding algorithm. The results for simple dielectric ridge waveguides are presented and compared with alternative solutions.