Parasitic high Q-factor open-box modes with 3-D printed dielectric-filled metal waveguides
Author(s)
Dawood, Attique
Lucyszyn, Stepan
Type
Journal Article
Abstract
High Q-factor open-box mode resonances have been found in the microwave measurements of several 3-D printed dielectric-filled metal-pipe rectangular waveguides (MPRWGs). These parasitic Fabry-Pérot eigenmodes are confined by the conductive walls in the transverse plane of the MPRWG and partially confined by the air-dielectric and dielectric-air boundaries in the longitudinal direction. The excitation of open-box modes was previously speculated to be due to the inhomogeneities and/or anisotropic nature of the 3-D printed dielectric-fillers. This has now been confirmed, by representing the inhomogeneous and anisotropic nature of the woodpile-like dielectric structure (physical realm), with an anisotropic dielectric constant tensor (simulation realm). Analytical and numerical eigenmode solvers, previously used by the authors with MPRWGs, are applied here to parallel-plate waveguides (PPWGs) and circular waveguides (CWGs); identifying all the individual parasitic open-box modes. With the former, its TM11 mode exhibits an ultra-high Q-factor of approximately 2,300 at X-band, which is considerably higher than those found with other modes and in other waveguide structures. Finally, a numerical full-wave frequency-domain simulator that employs the dielectric constant tensor is introduced in this paper. This new modeling technique independently confirms that open-box modes are excited in 3-D printed dielectric-filled MPRWG, PPWG and CWG structures. This paper provides the foundations for accurately modeling parasitic resonances associated with inhomogeneities and anisotropy in 3-D printed microwave components; not just the metal-walled waveguide structures considered here, but the methodology could also be extended to generic 3-D printed dielectric waveguides and substrate-based transmission lines.
Date Issued
2021-09-10
Date Acceptance
2021-09-08
Citation
IEEE Access, 2021, 9, pp.134319-134334
ISSN
2169-3536
Publisher
Institute of Electrical and Electronics Engineers
Start Page
134319
End Page
134334
Journal / Book Title
IEEE Access
Volume
9
Copyright Statement
© 2021 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
License URL
Sponsor
UK Space Agency
Identifier
https://ieeexplore.ieee.org/abstract/document/9535519
Grant Number
CT11834
Subjects
08 Information and Computing Sciences
09 Engineering
10 Technology
Publication Status
Published online
Article Number
Access-2021-30349
Date Publish Online
2021-09-10