Classical eigenvalue mode‐spectrum analysis of multiple‐ridged rectangular and circular waveguides for the design of narrowband waveguide components

Abstract

AbstractA classical eigenvalue mode‐spectrum analysis of waveguides with multi‐ridged cross sections is presented and applied to the design of narrowband waveguide components in rectangular and circular waveguide technology. Modifications of the modes of the empty waveguide enclosures are used as expansion functions and lead to a classical, real and symmetric eigenvalue problem. A simple yet efficient constraint function is introduced to satisfy boundary conditions for TM modes. The number and locations of ridges positioned in a regular rectangular or circular waveguide enclosure is arbitrary. Measurements and comparisons with results from existing full‐wave modeling tools and commercially available field solvers verify the correctness and flexibility of the approach. Copyright © 2009 John Wiley & Sons, Ltd.