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Stellenbosch University

1. Du Toit, Zainodean. Wideband low loss feed integration with a pyramidal sinuous antenna.

Degree: MEng, Electrical and Electronic Engineering, 2020, Stellenbosch University

ENGLISH ABSTRACT: In this thesis, a pyramidal sinuous antenna is designed to be integrated with a balun. This system is to be used as the feed of a shaped, offset Gregorian reflector. Initially, a previously designed Marchand balun is chosen due to its maximum amplitude and phase unbalance of ±0.2 dB and 1.5◦ , respectively. The balun matched the antennas 300 Ω real input impedance component across a 4.5:1 band. A new descrambling network is also designed to allow for the integration of two baluns, yielding a dual polarised sinuous antenna. Using this descrambling network, simulations showed that the antenna and balun integration matched a previous, single polarised integration. The simulated reflection coefficient remained below -10 dB across the majority of the band, reaching a maximum of -7.5 dB. The simulated radiation pattern also showed symmetry across the band, with a BOR1 (body of revolution type 1) efficiency above 90% and a reflector aperture efficiency above 70%. While the measured radiation pattern also showed symmetry, the reflection coefficient reached a maximum of -6 dB. Due to the measured reflection coefficient of the integrated balun and antenna, a Phelan balun is designed and suggested as an improvement. This balun was chosen for its inherent 4:1 impedance transformation. Balun simulations showed a maximum amplitude unbalance of 0.02 dB, and a maximum phase unbalance of 3.5% across a 0.26-1.8 GHz range. The simulated and measured reflection coefficient for this balun remained well below -10 dB across the same range.

AFRIKAANSE OPSOMMING:In hierdie tesis is ’n piramidiese sinusvormige antenna ontwerp om met ’n balun geïntegreer te word. Hierdie stelsel moet dan gebruik word as voer vir ’n gevormde, gekompenseerde Gregoriaanse weerkaatser. Aanvanklik word ’n voorheen ontwerpte Marchand-balun gekies as gevolg van sy maksimum amplitude en fase-onbalans van onderskeidelik ±0.2 dB en 1.5◦. Die balun pas by die antenna se 300 Ω reële invoerimpedansie-komponent oor ’n band van 1.05-4.7 GHz.’n Nuwe ontknopingsnetwerk is ook ontwerp om die inskakeling van twee baluns moontlik te maak, wat ’n dubbele gepolariseerde sinusvormige antenna lewer. Met behulp van hierdie ontknopingsnetwerk het simulasies getoon dat die antenna- en balun-integrasie ooreenstem met ’n vorige, enkel gepolariseerde integrasie. Die gesimuleerde weerkaatskoëffisiënt bly onder -10 dB oor die grootste deel van die band, en bereik ’n maksimum van -7.5 dB. Die gesimuleerde stralingspatroon het ook simmetrie oor die hele band getoon, met ’n BOR1 doeltreffendheid bo 90% en ’n reflektoropening doeltreffendheid bo 70%. Terwyl die gemete stralingspatroon ook simmetrie getoon het, bereik die weerkaatskoëffisiënt ’n maksimum van -6 dB. As gevolg van die gemete weerkaatskoëffisiënt van die geïntegreerde balun en antenna, word ’n Phelan-balun ontwerp en voorgestel as verbetering. Hierdie balun is gekies vir die inherente 4:1 impedansie transformasie. Simulasies het ’n maksimale amplitude-onbalans van 0.02 dB getoon, en ’n maksimum…

Advisors/Committee Members: Van Niekerk, C., De Villiers, D. I. L., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering..

Subjects/Keywords: Marchand-balun; Pyramidal sinuous antenna; Ultra-wideband antennas; Antennas (Electronics); UCTD

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APA (6th Edition):

Du Toit, Z. (2020). Wideband low loss feed integration with a pyramidal sinuous antenna. (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/107860

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Du Toit, Zainodean. “Wideband low loss feed integration with a pyramidal sinuous antenna.” 2020. Thesis, Stellenbosch University. Accessed December 02, 2020. http://hdl.handle.net/10019.1/107860.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Du Toit, Zainodean. “Wideband low loss feed integration with a pyramidal sinuous antenna.” 2020. Web. 02 Dec 2020.

Vancouver:

Du Toit Z. Wideband low loss feed integration with a pyramidal sinuous antenna. [Internet] [Thesis]. Stellenbosch University; 2020. [cited 2020 Dec 02]. Available from: http://hdl.handle.net/10019.1/107860.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Du Toit Z. Wideband low loss feed integration with a pyramidal sinuous antenna. [Thesis]. Stellenbosch University; 2020. Available from: http://hdl.handle.net/10019.1/107860

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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