Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: J. S. Preston. Includes bibliographical references (leaves 111-117).

Thesis (Ph.D.)--McMaster University (Canada), 1995. / Source: Dissertation Abstracts International, Volume: 57-03, Section: B, page: 1867. Adviser: T. Timusk.

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: leaf 199-216.

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 188-200.

Thesis (M.Sc.-Res.)--University of Wollongong, 2007. / Typescript. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [72]-80).

Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references.

Thesis (M.S.)--Florida State University, 2006. / Advisor: Justin Schwartz, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains xii, 43 pages. Includes bibliographical references.

Thesis (MScIng)--University of Stellenbosch, 2008. / ENGLISH ABSTRACT: The Applications of Superconductors in Cellular Network Base Stations R. Du Toit Department of Electronic Engineering University of Stellenbosch Private Bag X1, 7602 Matieland, South Africa Thesis: MScEng (E&E) March 2008 Wireless communications have increasingly become part of our world. The growth of radio frequency (RF) wireless communications has led to an increasing demand for frequency spectrum licenses, increased system capacity and larger user bandwidths. These demands lead to frequent improvements on the physical and higher layers of wireless communication protocols. Changes in the physical layer are frequently followed by the need for replacement of dedicated hardware components. The need therefore exists for a more general and programmable physical layer. A more general and programmable radio architecture implies increased radio front-end performance without losing programmability. The contribution of this thesis is the analysis of how superconductor electronics (SCE) using Rapid Single Flux Quantum (RSFQ) logic may advance wireless radio front-ends by providing a general-purpose programmable radio architecture. Superconductor analogue to digital converters (ADCs) are employed as high performance, programmable digitization structures. Once a received signal is digitized, SCE can be used to rapidly do recursive operations such as synchronization and multi-path delay estimation. These operations are based on correlation, and for evaluation of such operations with SCE the popular CDMA multiplexing method is studied along with the WCDMA protocol used in the 3G UMTS standard. Two delta-type oversampling superconductor ADC modulator designs are presented and evaluated along with a hybrid decimation filter design, using both the benefits of SCE and room temperature electronics. A fast RSFQ correlator design is also presented and evaluated for use in a multi-path estimation structure. A rapid multi-path delay estimation architecture based on fast RSFQ circular data buffers and correlators is presented. The architecture uses the fast speeds of RSFQ logic to obtain accurate path delay estimates in a rapidly changing wireless environment. It is concluded that RSFQ-based wireless receiver components offer promising new options for data conversion, correlation and multi-path delay estimation implementations. / AFRIKAANSE OPSOMMING: The Applications of Superconductors in Cellular Network Base Stations R. Du Toit Department of Electronic Engineering University of Stellenbosch Private Bag X1, 7602 Matieland, South Africa Thesis: MScEng (E&E) March 2008 Draadlose kommunikasie word al hoe meer deel van ons wêreld. Groei in radiofrekwensietipe kommunikasie het gelei tot ’n toenemende aanvraag na frekwensiespektrum lisensies, vergrote stelselkapasiteit en groter gebruikerbandwydtes. Hierdie aanvrae lei tot gereelde en spoedige verbeteringe op die fisiese en hoër lae van huidige draadlose kommunikasieprotokol. Veranderinge in die fisiese laag vereis gewoonlik dat toegewyde hardewarde komponente vervang word. Die behoefte bestaan dus vir ’n meer algemene, programmeerbare fisiese laag. Dit vereis dus ’n verbetering in die radio-ontvanger se komponente naaste aan die antenna sonder om programmeerbaarheid te verloor. Die bydrae van hierdie tesis is hoofsaaklik die analise van hoe supergeleierelektronika wat van Rapid Single Flux Quantum (RSFQ) logika gebruik maak, huidige draadlose sellulêre basisstasies se fisiese laag kan verbeter deur ’n meer algemene en programmeerbare radio-argitektuur op te lewer. Supergeleier analoog-na-syfer omsetters (ADCs) word bestudeer as moontlike programmeerbare versyferingstrukture wat steeds hoë werkverrigting lewer. Wanneer ’n ontvangde sein in digitale vorm omgesit is, kan supergeleierelektronika gebruik word om vinnig rekursiewe operasies uit te voer. Voorbeelde van sulke operasies is sinkronisasie en die waardebepaling van die vertraging van verskillende paaie wat ’n sein volg na die ontvanger. Hierdie spesifieke operasies se werking is gebaseer op korrelasie, en vir die evaluasie van sulke operasies met supergeleierelektronika is die gewilde wyeband-CDMA (WCDMA) protokol wat gebruik word in die 3G UMTS-standaard. Twee supergeleier-delta-tipe oorversyferings-ADC-moduleerderontwerpe word voorgelê en evaluasie word daarop gedoen saam met ’n hibriede desimasiefilterontwerp wat gebruik maak van beide die voordele van supergeleierelektronika en kamertemperatuurelektronika. ’n Vinnige RSFQ-korreleerder word ook voorgelê en evaluasie word daarop gedoen vir gebruik binne ’n multi-padvertraging-waardebepalerstruktuur. Hierdie struktuur wat gebaseer is op RSFQ sirkulêre buffers en korreleerders, word voorgelê. Die waardebepaler maak gebruik van die spoed van RSFQ-logika om akkurate multi-padvertragingswaardes te bepaal in ’n vinnig veranderende draadlose omgewing. Die gevolgtrekking word gemaak dat RSFQ-gebaseerde draadlose ontvangerkomponente groot voordele in versyfering-, korreleerder- en multi-padvertragingsbepaler-toepassings bied.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The nano-age is more about the mesoscopic phenomena, than those occurring at molecular and atomic level, which have been studied by chemists and physicists for more than a hundred years. Nanotechnology is currently one of the most active fields being explored in many different disciplines by many scientists across the world. In this research field, it is imperative to continually create more effective and superior methods to build smaller and smaller electronic devices, circuits and sensors. Technology is being improved continually and, specifcally at our university, there was a need to improve our device manufacturing facility. The aim of this work was to create a new sputtering system, build a dry etching system and to make modifications to upgrade existing equipment. This work has been done to produce nano structures or devices and, most importantly, to save costs. New systems and equipment have been built to keep up with the progress in this field. In order to understand the significance of the different types of equipment used in the fabrication of thin film superconductor layers, an overview will be given of the complete process of manufacturing a patterned Josephson junction. The apparatus used will be described and critically analyzed, whereby the shortfalls in design will be highlighted and improvements shown. Some of the equipment, such as the plasma laser deposition system, the lithography system and the test facility existed before and has been modified. Newly designed systems were built to further improve the quality of our thin film superconductors; these include the inverted cylindrical magnetron (ICM) sputtering system, the argon ion mill and the incandescent substrate heater. Finally, the results of the improved thin films and structures will be shown. To summarize: The entire process was analyzed and upgraded, resulting in an improved device manufacturing facility. / AFRIKAANSE OPSOMMING: Die nano-era het aangebreek en nanotegnologie is tans een van die mees aktiewe en diverse navorsingsvelde wat wetenskaplikes wêreldwyd ontgin - hoofsaaklik as gevolg van nuwe verskynsels op molekulêre en atomiese vlak. In die nanotegnologie-navorsingsveld is die vereiste dat daar voortdurend meer effektiewe metodes gevind moet word om die al hoe meer miniatuurwordende elektroniese meganismes met verbeterde energieverbruik, spoed en ruimtebesparende vermoëns tot stand te bring. Dit is duidelik dat in hierdie toonaangewende navorsingsveld, waar tegnologiese ontwikkeling voorturend en snelgroeiend is, dit dikwels vinniger is om reeds bestaande toerusting aan te pas en te moderniseer ten einde in pas te bly met nuutontwikkelde en ontwikkelende tegnologieë. Die doel van die werk verrig, wat hier beskryf word, was om 'n nuwe deponeerstelsel, sowel as 'n droogets stelsel te bou. Bestaande apparaat is opgradeer deur verandering aan te bring. Die uiteintelikke doel is die vervaarding van beter nano-strukture, en terselfde tyd om kostes te bespaar. Nuwe stelsels en toerusting is gebou om tred te hou met tegnologiese vooruitgang. Om die belangrikheid van die verskillende tipes toerusting wat in die vervaardiging van dunlaag- supergeleierlae gebruik word te verstaan, sal 'n oorsig van die volledige vervaardigingsproses van 'n Josephson-patroon gegee word. Die apparaat wat gebruik is, sal beskryf en krities ontleed word en die tekorte in ontwerp sal uitgelig word, terwyl verbeterings aangetoon sal word. Sommige van die toerusting het voorheen bestaan en is aangepas, byvoorbeeld die plasmalaser-neerleggingstelsel, die litografiestelsel en die toetsfasiliteit. Nuwe ontwerpstelsels is gebou om die gehalte van ons dunlaagsupergeleiers verder te verbeter. Dit sluit die silindriese plasma deponeer stelsel, die Argon-ioon bron en die substraatverwarmer in. In hierdie tesis word daar eerstens 'n oorsig gegee van die totstandkomingsproses van 'n supergeleier kwantum-interfensiemeganisme, beginnende met dunlaagneerslag van YBCO (Yttrium, Barium en Koperoksied). Die oorsig word gevolg deur 'n stap-virstap beskrywing van elke daaropvolgende proses wat lei tot die voltooiing van die meganisme. Daarna word die toetsprosedure van die dunlaag en instrumente verduidelik. Bykomende veranderinge wat aan bestaande instrumente aangebring is (ten einde die dunfilmlae te verbeter en die toetsfasiliteit op te gradeer) word ook bespreek. Daar sal ook verwys word na artikels wat in verskeie joernale verskyn het oor die vernuwende aanpassings en sisteme wat in hierdie tesis verduidelik word. Ten slotte sal die resultate van die verbeterde dunlae en strukture getoon word. Kortom: die hele proses is ontleed en opgegradeer om 'n verbeterde apparaatvervaardigingsfasiliteit tot gevolg te hê.