Mode Spectrum Eigenvalue Formulation for Irregular Waveguides and Its Application to Waveguide Component Design

Inhalt:
A new formulation to obtain the eigenmode spectra of irregular waveguides is presented. The method uses modified rectangular waveguide modes as expansion terms and leads to a classical eigenvalue problem. A two-dimensional negative rectangular step function is introduced to satisfy boundary conditions for TM modes. The procedure is combined with a mode-matching code and is used to analyse and design waveguide structures involving resonating components. The results are verified by measurements and comparison with existing full-wave modelling tools.