Abstract
The propagation constants of higher-order modes in lossy circular ducts are investigated with particular interest to the frequency range around the corresponding cutoff frequencies. The analytic expressions for the propagation constants published up to now contain poles at each cutoff frequency. In this article, it is shown that no poles exist. The transition between the frequency range of evanescent and propagating modes is rapid but continuous. An explicit formula for the propagation constant is derived. The theory is experimentally checked with an indirect measuring method that is able to give results in close vicinity to the cutoff frequencies. The measured attenuation due to the transmission line losses is partially somewhat higher than theoretically expected. The deviations are less than about 30%.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
