Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The use of Focal Plane Arrays (FPAs) as suitable feed-structures for the Parabolic Dish Reflector antennas that are intended to form a large part of the Square Kilometre Array (SKA) is currently the topic of conversation in various SKA research groups. The simulation of these structures however, relies on intensive computational resources, which can result in very long simulation runtimes - a serious problem for antenna designers. It was the purpose of the research to investigate efficient simulation techniques, based on the Method of Moments (MoM). In this thesis, the reader will be introduced to ways of improving FPA design by using resources such as High Performance Clusters, developing efficient MoM formulations for FPAs such as the Vivaldi antenna array and by developing efficient solution techniques for the resulting MoM equations by using techniques such as the Characteristic Basis Function Method (CBFM). In addition to the above mentioned methods, the concept of distributed computing is explored as a way to further aid the antenna designer in obtaining desired results in a reasonable time and with sufficient accuracy. / AFRIKAANSE OPSOMMING: Die gebruik van Fokus Punt Samestellings (FPS) vir die voer van Paraboliese Skottel Antennas in die Square Kilometer Array (SKA), geniet tans baie aandag in verkeie navorsing-sirkels. Die analise van hierdie samestellings vereis egter intensiewe berekenings-infrastrukture, wat tot lang simulasies kan lei - ’n ernstige probleem vir antenna ontwerpers. Die doel van die skrywer se navorsing was om effektiewe simulasie metodes te ondersoek, gebaseer op die Moment Metode. In hierdie tesis, sal die leser bekendgestel word aan verskeie metodes om die ontwerp van Fokus Punt Samestellings doeltreffend te verrig; nl. die gebruik van Parallel Rekenaar Klusters, die ontwikkeling van effektiewe Moment Metode kode vir samestellings soos die Vivaldi antenna konfigurasie, asook die ontwikkeling van effektiewe oplos-metodes vir die matrikse wat deur die Moment Metode gelewer word, deur die sogenaamde Karakteristieke Basis Funksie Metode (KBFM) te gebruik. Hierby ingesluit word die konsep van verspreide numeriese berekening ondersoek, as ’n manier waarop die antenna ontwerper resultate binne ’n aanvaarbare tyd en akkuraatheid kan verkry.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In this thesis we present GrMPy, a library of classes and functions implemented in Python, designed for implementing graphical models. GrMPy supports both undirected and directed models, exact and approximate probabilistic inference, and parameter estimation from complete and incomplete data. In this thesis we outline the necessary theory required to understand the tools implemented within GrMPy as well as provide pseudo-code algorithms that illustrate how GrMPy is implemented. / AFRIKAANSE OPSOMMING: In hierdie verhandeling bied ons GrMPy aan,'n biblioteek van klasse en funksies wat Python geim- plimenteer word en ontwerp is vir die implimentering van grafiese modelle. GrMPy ondersteun beide gerigte en ongerigte modelle, presies eenbenaderde moontlike gevolgtrekkings en parameterskat- tings van volledige en onvolledige inligting. In hierdie verhandeling beskryf ons die nodige teorie wat benodig word om die hulpmiddels wat binne GrMPy geimplimenteer word te verstaan sowel as die pseudo-kodealgoritmes wat illustreer hoe GrMPy geimplimenteer is.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The successful development of a three degree of freedom motion simulation platform, capable of simulating a vessel’s flight deck at sea, is presented. The motion simulation platform was developed to practically simulate and test an unmanned aerial vehicle’s capability of landing on a moving vessel, before practically being demonstrated on an actual vessel. All aspects of the motion simulation platform’s development are considered, from the conceptual design to its practical implementation. The mechanical design and construction of a pneumatic motion simulation platform, as well as the electronics and software to enable the operation of this motion simulation platform, are presented. Mathematical models of the pneumatic process and platform orientation are developed. A controller architecture capable of regulating the pneumatic process, resulted in the successful control of the motion simulation platform. Practical motion simulation results of one of the South African Navy Patrol Corvettes, demonstrate the motion simulation platform’s success. The successful development of the motion simulation platform can largely be attributed to extensive research, planning and evaluation of the different development phases. / AFRIKAANSE OPSOMMING: In hierdie studie word die suksesvolle ontwikkeling van ’n drie-grade-van-vryheid bewegingsimulasieplatform, wat in staat is daartoe om ’n skip se vliegdek ter see te simuleer, aangebied. Die bewegingsimulasieplatform is ontwikkel om ’n onbemande lugvaartuig se vermoë om op ’n bewegende skip te land, te simuleer en te toets, voor dit op ’n werklike skip gedemonstreer word. Alle aspekte van die ontwikkeling van die bewegingsimulasieplatform word in ag geneem – van die konsepontwerp tot die praktiese implementering daarvan. Die meganiese ontwerp en konstruksie van ’n pneumatiese bewegingsimulasieplatform word bespreek, sowel as die elektronika en programmatuur wat die werking van hierdie bewegingsimulasieplatform bemoontlik. Wiskundige modelle van die pneumatiese proses en platformoriëntering word ontwikkel. ’n Beheerderargitektuur wat in staat is daartoe om die pneumatiese proses te reguleer, lei tot die suksesvolle beheer van die bewegingsimulasieplatform. Praktiese resultate van die bewegingsimulering van een van die Suid-Afrikaanse Vloot se patrolliekorvette wys daarop dat die bewegingsimulasieplatform wel suksesvol is. Die geslaagde ontwikkeling van die bewegingsimulasieplatform kan grootliks toegeskryf word aan omvangryke navorsing, beplanning en evaluering van die onderskeie ontwikkelingsfases.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: An investigation into the cause of undesired sidelobes in the 3D radiation pattern of slotted waveguide arrays is conducted. It is hypothesized that the cross-polarization of the antenna is at fault, along with the possibility that an error is made when designing a linear array. In investigating and finding a solution to the problem, the “Z-slot ” is introduced in conjunction with polarizer plates. The base components are used by a custom optimization algorithm to design reference and solution antennas. Results of the antennas are then compared to ascertain the cause and possible solutions for the unwanted sidelobes. The generic nature of the process may be used to characterize other arbitrary aperture configurations and to design larger antennas. / AFRIKAANSE OPSOMMING: ‘n Ondersoek om die oorsaak van ongewensde sylobbe in die 3D uitstraalpatroon van golfleier-antennas vas te stel. Die hipotese is dat die probleem ontstaan uit die kruis-polarisasie van die antenna, tesame met ‘n verkeerdelikke aanname dat die opstelling liniêr is. Die “Z-Gleuf” tesame met polariseringsplate word voorgestel as hulpmiddel om die moontlikke oorsake te ondersoek. ‘n Gespesialiseerde optime erings-algoritme benut hierdie basiskomponente om beide verwysings- en oplossing-antennas te ontwerp. Resultate van die ontwerpde antennas word dan vergelyk om die oorsaak van die ongewensde sylobbe te vas te stel. Die generiese aard van die proses kan toegepas word op enige gleuf-konfigurasie en om groter antennas mee te ontwerp.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In this project, system identification is done on the Modular Unmanned Aerial Vehicle (UAV). This is necessary to perform fault detection and isolation, which is part of the Fault Tolerant Control research project at Stellenbosch University. The equations necessary to do system identification are developed. Various methods for system identification is discussed and the regression methods are implemented. It is shown how to accommodate a sudden change in aircraft parameters due to a fault. Smoothed numerical differentiation is performed in order to acquire data necessary to implement the regression methods. Practical issues regarding system identification are discussed and methods for addressing these issues are introduced. These issues include data collinearity and identification in a closed loop. The regression methods are implemented on a simple roll model of the Modular UAV in order to highlight the various difficulties with system identification. Different methods for accommodating a fault are illustrated. System identification is also done on a full nonlinear model of the Modular UAV. All the parameters converges quickly to accurate values, with the exception of Cl R , CnP and Cn A . The reason for this is discussed. The importance of these parameters in order to do Fault Tolerant Control is also discussed. An S-function that implements the recursive least squares algorithm for parameter estimation is developed. This block accommodates for the methods of applying the forgetting factor and covariance resetting. This block can be used as a stepping stone for future work in system identification and fault detection and isolation. / AFRIKAANSE OPSOMMING: In hierdie projek word stelsel identifikasie gedoen op die Modulêre Onbemande Vliegtuig. Dit is nodig om foutopsporing en isolasie te doen wat ’n deel uitmaak van fout verdraagsame beheer. Die vergelykings wat nodig is om stelsel identifikasie te doen is ontwikkel. Verskeie metodes om stelsel identifikasie te doen word bespreek en die regressie metodes is uitgevoer. Daar word gewys hoe om voorsiening te maak vir ’n skielike verandering in die vliegtuig parameters as gevolg van ’n fout. Reëlmatige numeriese differensiasie is gedoen om data te verkry wat nodig is vir die uitvoering van die regressie metodes. Praktiese kwessies aangaande stelsel identifikasie word bespreek en metodes om hierdie kwessies aan te spreek word gegee. Hierdie kwessies sluit interafhanklikheid van data en identifikasie in ’n geslote lus in. Die regressie metodes word toegepas op ’n eenvoudige rol model van die Modulêre Onbemande Vliegtuig om die verskeie kwessies aangaande stelsel identifikasie uit te wys. Verskeie metodes vir die hantering vir ’n fout word ook illustreer. Stelsel identifikasie word ook op die volle nie-lineêre model van die Modulêre Onbemande Vliegtuig gedoen. Al die parameters konvergeer vinnig na akkurate waardes, met die uitsondering van Cl R , CnP and Cn A . Die belangrikheid van hierdie parameters vir fout verdraagsame beheer word ook bespreek. ’n S-funksie blok vir die rekursiewe kleinste-kwadraat algoritme is ontwikkel. Hierdie blok voorsien vir die metodes om die vergeetfaktor en kovariansie herstelling te implementeer. Hierdie blok kan gebruik word vir toekomstige werk in stelsel identifikasie en foutopsporing en isolasie.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This report intends to show how able the Stellenbosch Electrical and Electronic Engineering Department’s micro fabrication laboratory is to manufacture nanomechanical switches and similar structures. Following the investigation, an attempt will be made to produce these devices. In attaining this goal, a literature study was performed focusing on mechanical switching and nanotechnology. Their origins, development and current application are investigated, as well as the requirements for developing these devices. Having completed the literature study, a series of current nanomechanical switches where investigated, selecting those most likely to be manufactured at the available facilities and having the required attributes for taking the place of silicon transistors in low speed, hostile environments. The most common method of manufacturing nanoswitches is simulated using several methods of predicting device failure. This will aid in the selection of manufacturing process guidelines, such as dimensions in the photoresist templates and layer thickness before etching, allowing for the repeated production of functional switches. The two manufacturable nanomechanical switches are investigated, using techniques and materials available at the micro fabrication laboratory to manufacture them. Subsequently, their electrical properties will be determined and used in simulating their failure characteristics. In conclusion, the result are discussed along with advice and improvements for the continued investigation and production of nanodevices at Stellenbosch University / AFRIKAANSE OPSOMMING: Die doel met hierdie tesis is om die vermoë van die Departement Elektriese en Elektroniese Ingenieurswese se mikro-elektronika laboratorium te ondersoek ten opsigte van die vervaardiging van nanomeganiese skakelaars en aanverwante komponente. Na afloop van die ondersoek sal ’n poging aangewend word om hierdie toestelle te vervaardig. In nastrewing van hierdie doel is ’n literatuurstudie uitgevoer wat fokus op meganiese skakeling en nanotegnologie. Die oorsprong, ontwikkeling en huidige aanwending van hierdie skakelaars word ondersoek, sowel as die vereistes vir die ontwikkeling daarvan. Na voltooiing van die literatuurstudie word ’n reeks van bestaande nanomeganiese skakelaars ondersoek. Skakelaars word dan geïdentifiseer op grond van hul waarskynlike vervaardigbaarheid met die beskikbare fasiliteite. Die vereiste eienskappe vir lae spoed toepassings in omgewings waar silikon-skakelaars nie kan werk nie, word ook in ag geneem. Die mees algemene metode vir die vervaardiging van nanoskakelaars word gesimuleer met behulp van verskeie tegnieke wat toestelfaling voorspel. Die simulasies sal help in die keuse van vervaardigingsriglyne van die proses, soos die dimensies van die fotolak template en die laagdiktes voor etsing, sodat goeie resultate verkry kan word wanneer die skakelaars vervaardig word, met goeie herhaalbaarheid. Die twee gekose vervaardigbare nanomeganiese skakelaars word dan ondersoek ten opsigte van die tegnieke en materiale wat in die mikro-elektronika laboratorium beskikbaar is. Daarna sal die elektriese eienskappe van die skakelaars bepaal word. Ter afsluiting word die resultate bespreek, saam met aanbevelings vir die voortsetting van die navorsing om nanomeganiese skakelaars by die Universiteit van Stellenbosch te vervaardig.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Worldwide, more large antenna arrays are being deployed in areas of science previously dominated by other antenna geometries. Applications for large arrays include Radar, Satellite Communications and Radio Astronomy. Even though the use of large arrays solve some of the difficulties posed by more traditional antennas, new challenges are also faced. One of these challenges is the problem of noise coupling, and how the overall system performance is affected by it. The Focal Plane Array (FPA), which is a new example of a large antenna array, is currently being researched at a number of institutions worldwide for use in Radio Astronomy. As a result, FPA’s were used as an example element to demonstrate the practical importance of this research. In this study, the effect of mutual coupling on the noise performance of FPA’s was illustrated. This was done by calculating the mutual coupling between the elements of the array, and then calculating the noise power received by each element as a result of the mutual coupling. Next, the Active Noise Figure and Active Noise Temperature were calculated. These parameters were introduced to visualise the effect of mutual coupling on the overall noise performance of the array. Since FPA’s are by definition large, conventional brute-force analysis techniques are very resource intensive. Solving the coupling terms using these methods therefore requires the use of computer clusters even during the design phase of the antenna, which is very expensive. A method was therefore developed to calculate the coupling terms of a large array using Periodic Boundary Conditions. The method uses infinite array analysis, which resulted in an improvement in memory usage in orders of magnitude. This improvement comfortably places the memory requirements for the analysis of large arrays within the range of current personal computers. The results also displayed a reasonable amount of accuracy for use during the design phase of an array. The additional noise power on each element as a result of mutual coupling were also calculated. This was achieved by developing an equivalent circuit diagram that represents the system in terms of the noise and transmission parameters of the LNA of each receiver channel, and the coupling terms of the antenna array. Lastly, the active noise temperature and active noise figure are calculated. The theory was implemented by means of a script with a graphical user interface, to provide easy-to-use access to the theory. A quick reference table of estimated noise coupling penalty versus first term coupling and LNA noise temperature was also compiled. The results of an example calculation showed a significant amount of noise coupling in an 8×8 Vivaldi array. The noise coupling resulted in an increase in system noise temperature, Tsys, in the order of 9% of the LNA noise temperature, TLNA. According to the SKA Tsys budget, this results in an approximate Tsys increase of 1.3 Kelvin. In the context of Radio Astronomy, this additional source of noise cannot be ignored, as it can greatly affect the usebility of the telescope for certain areas of research. / AFRIKAANSE OPSOMMING: Groot antennaskikkings word deesdae al hoe meer ingespan in plek van ander tradisionele antennamodelle. Toepassings vir groot antennaskikkings sluit Radar, Satellietkommunikasie en Radioastronomie in. Alhoewel die gebruik van groot antennaskikkings baie van die probleme wat deur ander tradisionele antennamodelle veroorsaak word oplos, word nuwe uitdagings terselfdertyd geskep. Een van hierdie nuwe uitdagins is ruiskoppelling en hoe dit die ruisgedrag van die stelsel as ’n geheel affekteer. ’n Beeldvlakskikking (FPA), is ’n opwindende nuwe voorbeeld van ’n groot antennaskikking en die moontlikheid vir die gebruik daarvan in radioastronomie word tans wêreldwyd nagevors. Om hierdie rede is die FPA gekies as voorbeeldelement om die bruikbaarheid van hierdie navorsing in die praktyk te beklemtoon. In hierdie studie word die effek van wedersydse koppelling op die ruisgedrag van FPA’s geïllustreer. Dit word gedoen deur eers die wedersydse koppelling tussen die elemente van die antennaskikking te bereken en dan die ruisdrywing wat deur elke element ontvang word as gevolg van wedersydse koppelling. Daarna word die Aktiewe Ruistal en die Aktiewe Ruistemperatuur bereken. Hierdie nuwe parameters word bekendgestel om die gevolge van wedersydse koppelling op die ruisgedrag van die stelsel as ’n geheel te visualiseer. Omdat FPA’s per definisie groot is, vereis die analise daarvan deur middel van konvensionele metodes baie rekenaar hulpbronne. Hierdie metodes vereis dus die gebruik van rekenaarbondels of superrekenaars selfs gedurende die ontwerpfase van die antenna, wat baie duur en onprakties is. Daar is dus ’n metode ontwikkel wat gebruik maak van periodiese randvoorwaardes om groot antennaskikkings te analiseer. Die metode benader ’n groot antennaskikking as ’n eindig-opgewekte oneindige skikking van antennas. As gevolg hiervan, word die geheueverbruik met ordegroottes verbeter. Hierdie verbetering plaas dus die analise van groot antennaskikkings binne die vermoëns van huidige persoonlike rekenaars. Die resultate wys ook ’n aanvaarbare graad van akkuraatheid vir gebruik gedurende die ontwerpfase van die skikking. Die bykomende ruisdrwying op elke element as gevolg van wedersydse koppelling is ook bereken. Om dit te vermag, is daar ’n ekwivalente stroombaandiagram ontwikkel wat die gekoppelde stelsel in terme van die ruis- en transmissieparameters van die laeruisversterker (LNA) aan elke ontvangerkanaal en die koppelterme van die antenna skikking voorstel. Laastens word die aktiewe ruistal en die aktiewe ruistermperatuur ook bereken. Die teorie is geïmplimenteer deur gebruik te maak van ’n grafiesegebruikerskoppelvlak (GUI). Die GUI verskaf aan die gebruiker maklike toegang tot die teorie wat onwikkel is in hierdie navorsing. Daar is ook ’n snelnaslaantabel geskep met benaderde waardes van ruiskoppelling vir ’n verskeidenheid waardes van LNA ruistemperature en eerste element koppelling. Die resultate van ’n 8×8 Vivaldiskikking voorbeeld, het ’n beduidende hoeveelheid ruiskoppelling getoon. Die ruiskoppelling het ’n maksimum toename in stelsel ruistemperatuur, Tsys, van ongeveer 9% van die LNA ruistemperatuur tot gevolg gehad. Volgens die huidige Tsys begroting van die SKA, kom dit neer op ’n Tsys toename van byna 1.3 Kelvin. In die konteks van die radioastronomie, kan hierdie toename in ruistemperatuur nie geïgnoreer word nie aangesien dit die bruikbaarheid van die teleskoop vir sekere velde van navorsing nadelig kan beïnvloed.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Organic semiconductors are used to manufacture thin film (smaller than 50nm) photovoltaic devices. Layer thicknesses are calibrated with the use of an AFM and QCM crystals. An in house method is prepared for solar cell comparison, and AM1.5G (one sun equivalent) testing is performed on manufactured solar cells. The importance of layer thickness and the exciton blocking layers are also highlighted. Numerical modelling of the optical electric field amplitude is done by the transfer matrix method, to take optical interference effects into consideration. The photo generated current was extracted as a function of absorption with varying position in the active layers, and used to excite a general model for organic photovoltaic cells. / AFRIKAANSE OPSOMMING: Organiese halfgeleiers word gebruik vir die vervaardiging van dun-film (kleiner as 50nm) fotovoltaïse toestelle. Laagdiktes is gekalibreer deur die gebruik van ’n AFM en QCM kristalle. ’n Inhuis metode is voorberei vir die vergelyking van vervaardigde selle. Daarna is AM1.5G (een son ekwivalente) toetse uitgevoer op die vervaardigde sonselle. Die belangrikheid van laag dikte en die “exciton” blok lae word ook beklemtoon. Numeriese modellering van die optiese elektriese veld amplitude word gedoen deur die oordrag matriks metode, om optiese interferensie gevolge in ag te neem. Die foto-gegenereerde stroom is as ’n funksie van absorpsie onttrek met wisselende posisie in die aktiewe lae, en is gebruik in ’n algemene model vir organiese fotovoltaïse selle.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Telephony has developed substantially over the years, but the fundamental auditory model of mixing all the audio from di erent sources together into a single monaural stream has not changed since the telephone was rst invented. Monaural audio is very di cult to follow in a multiple-source situation such as a conference call. Sound originating from a speci c point in space will travel along a slightly di erent path to each ear. Although we are not consciously aware of it, our brain processes these spatial cues to help us to locate sounds in space. It is this spatial information that allows us to focus our attention and listen to a single speaker in an environment where many di erent sources may be active at the same time; a phenomenon known as the \cocktail party e ect". It is possible to reproduce these spatial cues in a sound recording, using Head-Related Transfer Functions (HRTFs) to allow a listener to experience localised audio, even when sound is reproduced through a headset. In this thesis, spatial audio is implemented in a telephony application as well as in a virtual world. Experiments were conducted which demonstrated that spatial audio increases the intelligibility of speech in a multiple-source environment and aids active speaker identi cation. Resource usage measurements show that these bene ts are, however, not without a cost. In conclusion, spatial audio was shown to be an improvement over the monaural audio model traditionally implemented in telephony. / AFRIKAANSE OPSOMMING: Telefonie het ansienlik ontwikkel oor die jare, maar die basiese ouditiewe model waarin die klank van alle verskillende bronne bymekaar gemeng word na een enkelouditoriese stroom het nie verander sedert die eerste telefoon gebou is nie. Enkelouditoriese klank is baie moeilik om te volg in 'n meervoudigebron situasie, soos byvoorbeeld in 'n konferensie oproep. Klank met oorsprong by 'n sekere punt in die ruimte sal 'n e ens anderse pad na elke oor volg. Selfs is ons nie aktief bewus hiervan nie, verwerk ons brein hierdie ruimtelike aanduidinge om ons te help om klanke in die ruimte te vind. Dit is hierdie ruimtelike inligting wat ons toelaat om ons aandag te vestig en te luister na 'n enkele spreker in 'n omgewing waar baie verskillende bronne terselfdertyd aktief mag wees, 'n verskynsel wat bekend staan as die \skemerkelkiepartytjiee ek". Dit is moontlik om hierdie ruimtelike leidrade na 'n klank te reproduseer met behulp van hoofverwandeoordragfunksies (HRTFs) en om daardeur 'n luisteraar gelokaliseerde klank te laat ervaar, selfs wanneer die klank deur middel van oorfone gespeel word. In hierdie tesis word ruimtelike klank ge mplementeer in 'n telefonieprogram, sowel as in 'n virtuelew^ereld. Eksperimente is uitgevoer wat getoon het dat ruimtelike klank die verstaanbaarheid van spraak in 'n meerderebronomgewing verhoog en help met aktiewe spreker identi kasie. Hulpbrongebruiks metings toon aan dat hierdie voordele egter nie sonder 'n koste kom nie. Ter afsluiting, dit is bewys dat ruimtelike klank 'n verbetering tewees gebring het oor die enkelouditorieseklankmodel wat tradisioneel in telefonie gebruik het.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis presents an attempt at creating a fully functional SQUID for the purposes of a predefined application. The goal of the work is to provide a method of development, primarily utilising the facilities of the Engineering Faculty of the University of Stellenbosch, with minimal assistance from other departments. This method is then analysed and the successes and failures discussed in order to provide guidelines and recommendations for future research. The device consists of a gradiometric SQUID, as well as electronics which provide the SQUID bias current, output linearisation and output signal filtering. YBCO is used for the superconducting material, allowing the use of liquid nitrogen as coolant which eases the operation and portability of the device. Various methods of creating Josephson junctions are tested, such as constriction bridges using AFM lithography and step-edge junctions, with and without different buffer layers. Proof of concept simulations demonstrate the viability of the device. Unfortunately, a functional device could not be constructed, mostly due to the design requiring higher levels of resolution and process control than some of the available facilities can provide. Recommendations are provided for future researchers. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf ’n poging om ’n volledige funksionele SQUID te vervaardig vir die doeleindes van ’n vasgestelde toepassing. Die doel van die werk is om ’n metode te voorsien wat hoofsaaklik gebruik maak van die fasiliteite van die Ingenieurswese Fakulteit van die Universiteit van Stellenbosch, met minimale hulp van ander departemente. Hierdie metode word dan ondersoek en die suksesse en mislukkings bespreek om riglyne en voorstellings te voorsien vir toekomstige navorsing. Die toestel bestaan uit ’n gradiometriese SQUID, sowel as elektronika wat voorsiening maak vir voorspanning, uittree-linearisering en ’n uittree-filter. YBCO is as supergeleidende materiaal gebruik, wat die gebruik van vloeibare stikstof as verkoeler moontlik maak en dus die hantering en draagbaarheid van die toestel vergemaklik. Verskillende metodes om Josephson-vlakke te vervaardig is getoets, onder andere vernouingsbrugvlakke deur middel van AFM litografie en stapvlakke met en sonder bufferlae. Bewys van konsep simulasies demonstreer die lewensvatbaarheid van die toestel. Ongelukkig kon ’n funksionele weergawe van die toestel nie vervaardig word nie, hoofsaaklik as gevolg van die ontwerp wat hoër resolusievlakke en beter prosesbeheer benodig as wat sekere van die beskikbare fasiliteite kan voorsien. Aanbevelings word voorsien vir toekomstige navorsers.