Linear sparse regular array antenna demonstrator

Weideman, Rina-Mari (2021-03)

Thesis (MEng)--Stellenbosch University, 2021.

Thesis

ENGLISH ABSTRACT: Sparse uniform linear arrays (ULAs), i.e., arrays with adjacent elements spaced further than a half-wavelength, have advantages over dense ULAs, such as an improved resolution for the same number of receivers and reduced mutual coupling e ects. Due to the sparse ULAs not satisfying the spatial Nyquist criterion, however, aliasing is introduced when applying direction of arrival (DOA) estimation methods, meaning that ambiguous results are achieved. A new DOA estimation method based on exponential analysis, called Validated Exponential Analysis (VEXPA) has been developed in [1] to overcome this problem, making use of the aliasing e ect rather than avoiding it. This project investigated the practical performance of VEXPA. We found that the use of VEXPA with sparse arrays can improve the angular resolution with a factor of up to ve from that of a dense array. The biggest drawback of the technique was found to be the speci c case when multiple signals are unable to be distinguished from each other. The method also struggles to deliver accurate results with low-resolution quantised data, which is a disadvantage as high-resolution quantisers are costly and require an intricate design process. A small four-element prototype antenna array was manufactured. Experiments were performed in an anechoic chamber with a single source. The results returned by VEXPA proved to be accurate.

AFRIKAANSE OPSOMMING: Yl eenvormige reëlmatige skikkingsantennas, d.w.s. skikkingsantennas met aangrensende elemente verder as 'n half-gol engte gespasieër, het voordele bo digte eenvormige reëlmatige skikkingsantennas, soos 'n verbeterde resolusie vir dieselfde aantal ontvangers en verminderde wedersydse koppeling. As gevolg van die feit dat yl eenvormige reëlmatige skikkingsantennas nie die ruimtelike Nyquist kriterium nakom nie, word aliasering veroorsaak wanneer rigtingsafskatting metodes toegepas word, wat beteken dubbelsinnige resultate word gelewer. 'n Nuwe rigtingsafskatting metode wat gebaseer is op eksponensiële analise, met die naam van Bevestigde Eksponensiële Analise ("VEXPA"), is ontwerp in [1] om hierdie probleem te oorkom, waar daar eerder van die aliasering gebruik gemaak word as om dit te probeer voorkom. Hierdie projek het die praktiese uitvoering van VEXPA ondersoek. Ons het gevind dat die gebruik van VEXPA met yl skikkingsantennas die resolusie tot 'n faktor van vyf kan verbeter van die resolusie wat 'n digte skikkingsantenna bied. Die grootste nadeel van die tegniek is die geval wanneer meervoudige seine nie van mekaar onderskei kan word nie. Hierdie metode sukkel ook om akkurate resultate te lewer met lae-resolusie gekwantiseerde data, wat 'n nadeel is omdat hoë-resolusie kwantiseerders duur is en 'n ingewikkelde ontwerpproses behels. 'n Klein vier-element prototipe skikkingsantenna was vervaardig. Eksperimente was uitgevoer in 'n anechoïese kamer met 'n enkele bron. Die resultate gelewer deur VEXPA was akkuraat.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/109795
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