Calculations on Mode Eigenvalues in a Corrugated Waveguide with Varying Diameter and Corrugation Depth

The present paper addresses numerical calculations on the eigenvalues of hybrid modes in corrugated circular waveguides with varying diameter and corrugation depth. Such calculations are essential for the numerical optimization of advanced mode converters and diameter tapers for future low-loss high-power microwave applications, like broadband high-power radar sensors for space debris observation in low earth orbit (LEO). Corresponding mode converters and diameter tapers may be synthesized based on coupled mode theory. Of particular importance here is the ability to consider varying mode eigenvalues along the perturbed waveguide. The procedure presented here is able to consider arbitrary variations of the corrugation depth as well as the waveguide diameter and therefore is highly flexible. The required computational effort is low. Limitations of the method are discussed.