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Parametric beam modeling for reflector antennas
Venter, M. 2025. Parametric Beam Modeling for Reflector Antennas. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d797a472-0978-42d0-97ab-540d51d5f89f
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614088312389632 |
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| access_status_str | Open Access |
| author | Venter, Mariet |
| author2 | De Villiers, Dirk I. L. |
| author_browse | De Villiers, Dirk I. L. Venter, Mariet |
| author_facet | De Villiers, Dirk I. L. Venter, Mariet |
| author_sort | Venter, Mariet |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Venter, M. 2025. Parametric Beam Modeling for Reflector Antennas. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d797a472-0978-42d0-97ab-540d51d5f89f |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132327 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:28.519Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132327 Parametric beam modeling for reflector antennas Venter, Mariet De Villiers, Dirk I. L. Stellenbosch University. Faculty of Engineering. Dept. of Electrical & Electronic Engineering. Antenna radiation patterns Radio astronomy Parametric modeling UCTD Antennas, Reflector -- Design and construction Venter, M. 2025. Parametric Beam Modeling for Reflector Antennas. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d797a472-0978-42d0-97ab-540d51d5f89f Thesis (PhD)--Stellenbosch University, 2025. ENGLISH ABSTRACT: Reflector antennas with accurately known beam patterns are essential in radio astronomy, due to the science observation including the effects of the beam pattern shape and resulting performance characteristics. If the pattern is known or can be modeled accurately, it can be removed from the observation to produce high fidelity science images. Strategies to address this challenge include the custom design of antenna elements for specific science cases, or accurately predicting the resulting beam pattern by using electromagnetic simulation or measurement. The former aims to minimise the error that the beam pattern adds to the observation, but carries with it the complicated relationship between the antenna performance and the image quality, which is not well defined for large telescope arrays. This dissertation investigates aspects of both strategies with the focus on beam modeling methods, aimed at improving the efficiency of feed design and optimisation. A simplified science imaging pipeline is developed to link antenna beam performance directly to image quality, but it is found that in order to obtain useful results, the pipeline requires more complexity, which in turn limits its use in rapid feed optimisation workflows. As a result, the focus shifts towards antenna beam modeling techniques. In this context, Characteristic Basis Function Pattern (CBFP) methods are explored for predicting beam patterns over a range of frequencies and geometrical perturbations of the antenna. The role of frequency in this regard is investigated with the goal of treating it in the most optimal manner when reconstructing beam patterns from the available basis functions. The results suggest that incorporating the frequency variation of the radiation pattern to account for geometric variations in the physical antenna could significantly enhance modeling capabilities while requiring fewer geometric perturbations of the antenna element. In addition, by interpolating CBFP coefficients across elevation of a re‑ flector antenna and incorporating surface error data, it is shown that patterns at new elevations can be predicted with high accuracy. The dissertation also introduces a novel approach for beam modeling of a feed on a reflector. By leveraging a known reference reflector and applying scaling and normalisation, the difference patterns between the reflectors can be used in a CBFP interpolation framework. The method spans a multi‑dimensional design space and demonstrates reduced computational cost compared to modeling the target reflector directly. This approach is further validated in an optimisation framework, where it successfully enhances feed performance with a limited number of electromagnetic simulations. The results of this work demonstrate that efficient, accurate beam modeling techniques can significantly reduce the effort and computational demands of antenna design processes, adding to the suite of valuable tools for radio astronomy applications. AFRIKAANSE OPSOMMING: Weerkaatsantennas met welbekende stralingspatrone is noodsaaklik in radiosterrekunde. ’n Wetenskaplike waarneming sluit die effekte van die antenna se stralingspatroonvorm en gevolglike werkverrigting‑eienskappe in. As die patroon bekend is of akkuraat voorspel kan word, kan dit uit die waarneming verwyder word om wetenskaplike beelde met hoë getrouheid te produseer. Strategieë om hierdie uitdaging aan te spreek sluit in die pasgemaakte ontwerp van antennaelemente vir spesiieke wetenskaplike gevalle, of die akkurate voorspelling van die gevolglike stralingspatroon deur gebruik te maak van elektromagnetiese simulasie of meting. Eersgenoemde het ten doel om die fout wat die stralingspatroon tot die waarneming toevoeg, te minimeer, maar dra die ingewikkelde verhouding tussen die antenna‑werkverrigting en die beeldkwaliteit saam, wat nie goed gedeinieer is vir groot teleskoopsamestellings nie. Hierdie proefskrif ondersoek aspekte van beide strategieë met die fokus op modelleringsmetodes, wat daarop gemik is om die doeltreffendheid van voerontwerp en optimering te verbeter. ’n Vereenvoudigde beeldpyplyn is ontwikkel om die werkverrigting van antennastraling direk aan beeldkwaliteit te koppel, maar daar word gevind dat die pyplyn meer kompleksiteit benodig om bruikbare resultate te verkry, wat weer die gebruik daarvan in vinnige optimeringswerkvloeie vir voere beperk. Gevolglik verskuif die fokus na modelleringsmetodes vir stralingspatrone. In hierdie konteks word karakteristieke basisfunksiepatroon (KBFP) metodes ondersoek vir die voorspelling van antennapatrone oor ’n reeks frekwensies en geometriese versteurings van die antenna. Die rol van frekwensie in hierdie verband word ondersoek met die doel om dit op die mees optimale wyse te hanteer wanneer stralingspatrone gerekonstrueer word vanaf die beskikbare basisfunksies. Die resultate dui daarop dat die inkorporering van die rekwensievariasie van die stralingspatroon, om rekening te hou met geometriese variasies in die isiese antenna, modelleervermoëns aansienlik kan verbeter terwyl minder geometriese versteurings van die antenna‑element vereis word. Daarbenewens, deur KBFP‑koëfisiënte oor elevasie van ’n weerkaatser te interpoleer en die oppervlakfoutdata in te sluit, word dit getoon dat patrone by nuwe elevasies met hoëakkuraatheid voorspel kan word. Die proefskrif stel ook ’n nuwe benadering tot stralingsmodellering van ’n over op ’n weerkaatser bekend. Deur ’n bekende verwysingsweerkaatser te gebruik en skalering en normalisering toe te pas, kan die verskilpatrone tussen die weerkaatsers in ’n KBFP‑interpolasieraamwerk gebruik word. Die metode strek oor ’n multidimensionele ontwerpruimte en demonstreer verminderde berekeningskoste in vergelyking met die direkte modellering van die teikenweerkaatser. Hierdie benadering word verder bekragtig in ’n optimeringsraamwerk, waar dit voerprestasie suksesvol verbeter met ’n beperkte aantal elektromagnetiese simulasies. Die resultate van hierdie werk demonstreer dat doeltreffende, akkurate tegnieke vir die modellering van stralingspatrone die moeite en berekeningsvereistes van antenna‑ontwerpprosesse aansienlik kan verminder, wat bydra tot die reeks waardevolle gereedskap vir radio‑sterrekundetoepassings. Doctoral 2025-06-04T05:38:28Z 2025-06-04T05:38:28Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132327 en Stellenbosch University viii, 66 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Antenna radiation patterns Radio astronomy Parametric modeling UCTD Antennas, Reflector -- Design and construction Venter, Mariet Parametric beam modeling for reflector antennas |
| title | Parametric beam modeling for reflector antennas |
| title_full | Parametric beam modeling for reflector antennas |
| title_fullStr | Parametric beam modeling for reflector antennas |
| title_full_unstemmed | Parametric beam modeling for reflector antennas |
| title_short | Parametric beam modeling for reflector antennas |
| title_sort | parametric beam modeling for reflector antennas |
| topic | Antenna radiation patterns Radio astronomy Parametric modeling UCTD Antennas, Reflector -- Design and construction |
| url | https://scholar.sun.ac.za/handle/10019.1/132327 |
| work_keys_str_mv | AT ventermariet parametricbeammodelingforreflectorantennas |