A finite element approach for lossy waveguide analysis

Presents an approach which is based on an automatised E_z-H_z formulation which was introduced by Aubourg et al. (1983). In this formulation the frequency is a parameter and (α,β), the attenuation and the phase constants, respectively; are calculated through a fast iterative automatic procedure. However, a difficulty exists for a first fixed frequency. If the initial (α,β) values, are too far from the exact ones, the method can converge to a different mode. But, after a good result, the dissipative and dispersive curves can be quickly and efficiently calculated, since the initialization is made with the same α and β as the ones obtained for the previous frequency. The efficiency and validity of this approach has been examined by analysing lossy dielectric-loaded metallic waveguides which possess analytical solution, as well as, lossy image waveguides