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Optimisation-based characterisation of multimodal waveguide transitions
Thesis (MEng)--Stellenbosch University, 2023.
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| Format: | Thesis |
| Language: | en_ZA en_ZA |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613759002902528 |
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| access_status_str | Open Access |
| author | Wessels, Bea |
| author2 | Meyer, Petrie |
| author_browse | Meyer, Petrie Wessels, Bea |
| author_facet | Meyer, Petrie Wessels, Bea |
| author_sort | Wessels, Bea |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/127136 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:41:14.564Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/127136 Optimisation-based characterisation of multimodal waveguide transitions Wessels, Bea Meyer, Petrie Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Wave guides -- Calibration Multimodal characterization Coaxial cables Thesis (MEng)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Coaxial-to-waveguide calibration is a challenging subject, due to the limitations of calibration standards and multimodal propagation within the waveguide. This project aims to develop a method which allows the multimodal characterisation of a rectangular waveguide. A waveguide is difficult to characterise due to the possibility of multiple modes propagating within the waveguide. Non-coaxial calibration techniques already exist, and two of them are discussed and evaluated in this project. The theory of mode propagation in rectangular waveguides is researched and discussed, to provide the necessary background knowledge. The mathematical deem bedding of two known network analyser calibration techniques, namely SOLT and TRL, is explained. Furthermore, the de-embedding of both these techniques is programmed in MATLAB and used to perform a manual calibration. The manual calibration is performed using non-waveguide devices as DUT’s to show how successful the de-embedding of each technique is. The techniques are further each evaluated within the context of waveguide calibration. After the standard calibration techniques are evaluated in terms of the requirements of this project, an alternative method of waveguide characterisation is introduced. The measurement of the waveguide is conducted at a coaxial pin inserted at the top of the waveguide. This technique relies on the characterisation of the waveguide by implementing a set of offset shorts at one port and measuring at the inserted coaxial pin. The mathematical procedure for this calibration is discussed and programmed in MATLAB. The measurement of the rectangular waveguide using the inserted coaxial pin is simulated in CST Studio Suite and the measurements are implemented in the alternative calibration technique. A reduced-height waveguide is introduced to investigate the propagation of specified modes. The formulation as discussed for the standard waveguide is also introduced for the reduced-height waveguide. Lastly, a two-port waveguide characterisation is investigated that inserts a DUT in between two coaxial-to-waveguide transitions. The DUT is characterised using coaxial measurements only, also for multiple propagating modes. AFRIKAANSE OPSOMMING: Dit is moelik om ’n koaksiale-na-golfleier kalibrasie te betoon, aangesien dit beperk is deur die voortplanting van meer as een modus in die golfleier, asook die beperkings wat gebied word deur kalibrasie standaarde. Hierdie tesis ondersoek die moontlikheid dat die S-parameters van ’n standaard X-band golfleier gekarakteriseer kan w ord. As gevolg van die moontlikheid dat meer as een modus kan voortplant in die golfleier, is dit baie moeilik of hierdie toestel te kalibreer. Nie-koaksiale kalibrasie tegnieke is klaar gevestig, waarvan twee van hulle in hierdie projek bespreek word. Om agtergrond te verskaf oor reghoekige golfleiers, i s die t eorie van die tipe modusse wat voortplant in ’n reghoekige golfleier b espreek. Twee kalibrasie tegnieke wat reeds gebruik word vir ’n netwerk analiseerder, naamlik SOLT en TRL, is ondersoek. Hierdie tegnieke word wiskundig gevolg en in MATLAB geprogrammeer om die kalibrasie tegnieke te ondersoek. Die kalibrasie tegnieke word geimplementeer deur gebruik te maak van nie-golfleier t oestelle, m et d ie d oel o m e lke t egniek individueel te toets. Van daar af word die tegnieke in die konteks van golfleier-kalibrasie evalueer. Nadat die standaard kalibrasie tegnieke bespreek is ten opsigte van die vereistes van hierdie projek, is ’n alternatiewe metode voorgestel. Die metings vind plaas op die punt van ’n koaksiale poort wat aan die bokant van die golfleier ingesit i s. Hierdie tegniek behels dat al die metings geneem word by die koaksiale poort in die golfleier, en dat ’n stel kortings by een poort implementeer word. Die wiskundige metode wat hierdie tegniek verduidelik word betoon, sowel as die programmering van die model in MATLAB. Die meting van die koasiale-na-golfleier sisteem is in CST Studio Suite implementeer en die metings word gebruik in die alternatiewe tegniek. iv Stellenbosch University https://scholar.sun.ac.za UITTREKSEL v ’n Golfleier met ’n verkorte hoogte word as ’n opvolg vir die standaard golfleier voorgestel, om die voortplanting van sekere modusse te forseer. Die model wat opgestel is vir die standaard golfleier word net so ook gebruik vir die golfleier met ’n verkorte hoogte. Laastens word ’n dubbele golfleier model voorgestel, waarin ’n onbekende toestel tussen twee koasiale-na-golfleier oorgange ingevoeg word. Die onbekende toestel word dan volledig vir veelvoudige modusse gekarakteriseer deur slegs gebruik te maak van die koaksiale metings. Masters 2023-03-02T08:16:46Z 2023-05-18T07:06:03Z 2023-03-02T08:16:46Z 2023-05-18T07:06:03Z 2023-03 Thesis http://hdl.handle.net/10019.1/127136 en_ZA en_ZA Stellenbosch University xiv, 139 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Wave guides -- Calibration Multimodal characterization Coaxial cables Wessels, Bea Optimisation-based characterisation of multimodal waveguide transitions |
| title | Optimisation-based characterisation of multimodal waveguide transitions |
| title_full | Optimisation-based characterisation of multimodal waveguide transitions |
| title_fullStr | Optimisation-based characterisation of multimodal waveguide transitions |
| title_full_unstemmed | Optimisation-based characterisation of multimodal waveguide transitions |
| title_short | Optimisation-based characterisation of multimodal waveguide transitions |
| title_sort | optimisation based characterisation of multimodal waveguide transitions |
| topic | Wave guides -- Calibration Multimodal characterization Coaxial cables |
| url | http://hdl.handle.net/10019.1/127136 |
| work_keys_str_mv | AT wesselsbea optimisationbasedcharacterisationofmultimodalwaveguidetransitions |