A utilização de etiquetas RFID UHF passivas para localização indoor vem sendo amplamente estudada devido ao seu baixo custo. Porém ainda existe uma grande dificuldade em obter bons resultados, principalmente devido à variação de rádio frequência em ambientes que possuem materiais reflexivos, como por exemplo, metais e vidros. Esta pesquisa propõe uma arquitetura de localização para ambientes indoor utilizando etiquetas RFID UHF passivas e técnicas de mineração de dados. Com a aplicação da arquitetura em ambiente real foi possível identificar a posição exata de objetos com a precisão de aproximadamente cinco centímetros e em tempo real. A arquitetura se demonstrou uma eficiente alternativa para implantação de sistemas de localização indoor, além de apresentar uma técnica de derivação de atributos diretos que contribui efetivamente para os resultados finais. / The use of passive UHF RFID tags for indoor location has been widely studied due to its low cost. However, there is still a great difficulty to reach good results, mainly due the radio frequency variation in environments that have materials with reflective surfaces, such as metal and glass. This research proposes a localization architecture for indoor environments using passive UHF RFID tags and data mining techniques. With the application of the architecture in real environment, it was possible to identify the exact position of objects with the precision of approximately five centimeters and in real time. The architecture has demonstrated an efficient alternative for the implantation of indoor localization systems, besides presenting a derivation technique of direct attributes that contributes effectively to the final results.

Radio astronomy is the science of observing the heavens at radio frequencies, from a few kHz to approximately 300 GHz. In recent years, radio astronomy has faced a growing interference problem as radio frequency (RF) bandwidth has become an increasingly scarce commodity. A programmable real-time DSP least-mean-square interference canceller was developed and demonstrated as a successful method of excising satellite down-link signals from both an experimental platform at BYU, and the Green Bank Telescope at the National Radio Astronomy Observatory in West Virginia. A performance analysis of this cancellation system in the radio astronomy radio frequency interference (RFI) mitigation regime constitutes the main contribution of this thesis. The real-time BYU test platform consists of small radio telescopes, low noise RF receivers, and a state-of-the-art DSP platform. This programmable real-time radio astronomy RFI mitigation tool is the first of its kind. Basic tools needed for radio astronomy observations and the analysis and implementation of interference mitigation algorithms were also implemented in the DSP platform, including a power spectral density estimator, a beamformer, and an array signal correlator.

Thesis ( M. Tech. (Business Administration )) - Central University of Technology, Free State, 2014 / Fast and secure public service delivery is not only a necessity, but a compulsory endeavour. However, it is close to impossible to achieve such objectives without the use of Information Technology (IT). It is correspondingly important to find proper sustainability frameworks of technology. Organisations do not only need technology for efficient public service; the constant upgrading of systems and cautious migration to the newest IT developments is also equally indispensable in today’s dynamic technological world. Conversely, countries in Africa are always lagging behind in technological progresses. Such deficiencies have been identified in the passport processing of Lesotho and South Africa, where to unequal extents, problems related to systems of passport production have contributed to delays and have become fertile grounds for corrupt practices. The study seeks to identify the main impediments in the adoption of Management Information Systems (MIS) for passport processing. Furthermore, the study explores the impact MIS might have in attempting to combat long queues and to avoid long waiting periods – from application to issuance of passports to citizens. The reasonable time frame between passport application and issuance, and specific passport management systems, have been extensively discussed along with various strategies that have been adopted by some of the world’s first movers in modern passport management technologies. In all cases and stages of this research, Lesotho and South Africa are compared. The research approach of the study was descriptive and explorative in nature. As a quantitative design, a structured questionnaire was used to solicit responses in Lesotho and South Africa. It was established that both Lesotho and South Africa have somewhat similar problems – although, to a greater extent, Lesotho needs much more urgent attention. Although the processes of South Africa need to be improved, the Republic releases a passport much faster and more efficiently than Lesotho. Economic issues are also revealed by the study as unavoidable factors that always affect technological developments in Africa. The study reveals that the latest MIS for passport processing has facilitated modern, automated border-control systems and resultant e-passports that incorporate more biometric information of citizens to passports – thanks to modern RFID technologies. One can anticipate that this study will provide simple, affordable and secure IT solutions for passport processing. Key words: Information Technology (IT); Management Information Systems (MIS); E-Government; E-Passport; Biometrics; and RFID.

Thesis presented in partial fulfilment of the requirements for the Master's Degree of Technology: Information Technology, Durban University of Technology, 2008. / Radio Frequency Identification (RFID) allows for the wireless transfer of data between a small electronic transmitting tag and a reader without the necessity of line-of-sight. A feature of RFID, is that this read operation may occur over long distances and that multiple reads may occur. The aim of this study is to analyse the nature and extent of RFID adoption in the KwaZulu-Natal Province of South Africa. The study fits within the theory of innovation diffusion and is concerned with issues around technology diffusion, adoption rates, and its associated critical success factors. The estimation of RFID diffusion rate in the study is based on a telephonic survey of 140 companies. The respondents were chosen from a marketing database that had extensive information on South African companies. Size was determined to be the selection criterion as the literature indicates that size is the most compelling concomitant to innovativeness. In this study, size was deemed to be companies that had more than 50 PC’s in one geographic unit, of the company, in KwaZulu-Natal. The key research result locates the RFID diffusion rate in KwaZulu-Natal to be around 19% which corresponds to points beyond the “chasm” as defined by innovation diffusion theory. The second phase of the study comprised the administration of a questionnaire to two groups of IT professionals with the aim of comparing perceptions and other characteristics between the two groups. The 140 respondents were asked to submit as many professional staff as they could for an in-depth interview. The result was that 21 companies submitted 30 candidates. This yielded the two groups: the Adopter sample with 14 respondents, and the non-adopter sample with 16 respondents. The analysis of results shows the two groups have similar views on many strategic factors such as privacy, security, cost and standards etc. Adopters perceive that the following factors impacts RFID adopting decisions more (than non-adopters): Turnover, Having labour cost savings, RFID ubiquity, It will take as long for my company to adopt RFID as it did for barcode, RFID cost awareness. On the other hand non-adopters felt that the following factor impacts non-adoption of RFID Technology unproven or immature, Human skills non-availability, Implementation costs, Corporate resistance, and, Support Concerns.

Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: RFID technology may be the most capable technology to address the track and trace requirements within the Agri-food supply chain. RFID technology has become a prominent research area in recent times, with multiple benefits being promised and envisaged. The list of applications and deployments within the supply chain is numerous, with the ambassadors of this technology promising increased supply chain effectiveness, inventory management capabilities and enhanced information visibility. Deregulations within the South African citrus industry created changes to the internal structure of the industry, with the requirements of enhanced information visibility for traceability becoming a high priority. Current information structures and initiatives are providing the basic requirements for the changing business environment, with limitations to real-time and visible information for improved decision-making and planning initiatives. The purpose of this exploratory study was to identify the critical success factors for RFID technology deployment in supply chains in general and to identify the critical success factors relevant to the South African citrus industry. The study also researched the benefits and challenges of deploying RFID technology within the South African citrus industry, relating to citrus supply chain performance improvements of RFID adoption. The research indicates that certain limitations and challenges pertinent to the citrus industry exist, which would require industry level priority for successful implementation of RFID technology within the South African citrus industry. This study provides the South African citrus industry with a guideline to address the current non-collective management of information, information systems and requirements and collaboration initiatives. The use of this research should be of great assistance to the South African citrus industry role-players by providing a strategic framework for addressing information improvement initiatives. / AFRIKAANSE OPSOMMING: RFID tegnologie kan moontlik die mees bevoegde tegnologie wees om die naspeurbaarheid vereistes van n Agri-voedsel voorsiening ketting aan te spreek. RFID tegnologie is huidiglik 'n prominente navorsingsgebied, met beloofde meervoudige voordele. Die lys van aanwendings en toepassings binne die voorsiening ketting is veelvoudig, met beloftes van die ambassadeurs van die tegnologie, vir verbeterde voorsienings ketting doeltreffendheid, inventaris bestuur en verhoogde inligtings sigbaarheid. Deregulasie van die Suid Afrikaanse sitrus industrie het interne strukturuele veranderinge in die industrie teweeg gebring, met prioriteit fokus vir verhoogde inligting sigbaarheid vir naspeurbaarheid doeleindes. Huidige inligting strukture en initiatiewe verskaf die basiese grondslag vir die deurlopende veranderende besigheids omgewing, met intyd en sigbaarheids inligtings beperkinge, vir verbeterde besluitneming en beplanning initiatiewe. Die doel van die ondersoekende studies was om die generiese kritieke sukses faktore van RFID tegnologie implementering en die kritieke sukses faktore direk verwant tot die Suid Afrikaanse sitrus industrie te identifiseer. Die studie het ook die voordele en uitdagings van RFID implementering binne die Suid Afrikaanse sitrus industrie nagevors, spesifiek verwant tot die prestasie verbeterings van RFID implementering in die sitrus voorsienings ketting. Die navorsing dui aan dat sekere beperkinge en uitdagings spesifiek tot die sitrus industrie bestaan wat industrie vlak prioriteit vereis, vir suksevolle implementasie van RFID tegnologie binne die Suid Afrikaanse sitrus industrie. Die resultate van die studie verskaf die Suid Afrikaanse sitrus industrie met 'n riglyn om die uitdagings van die huidige nie-kollektiewe bestuur van inligting, inligting stelsels en vereistes en samewerkings initiatiewe aan te spreek. Die gebruik van die navorsing behoort van groot waarde te wees vir die rolspelers van die Suid Afrikaanse sitrus industrie, in die verskaffing van 'n strategiese raamwerk vir die aanspreking van inligting verbeterings intiatiewe.

<p>In this thesis, design and realization of a system which enables precise positioning of RFID tags in both azimuth and elevation angles is explained. The positioning is based on measuring the phase difference between four Yagi antennas placed in two arrays. One array is placed in the azimuth plane and the other array is perpendicular to the first array in the elevation plane. The phase difference of the signals received from the antennas in the azimuth array is used to find the position of RFID tag in the horizontal direction. For the position in the vertical direction, the phase difference of the signals received from the antennas in the elevation plane is used. After that the position of tag in horizontal and vertical directions is used to control the mouse cursor in the horizontal and vertical directions on the computer screen. In this way by attaching one RFID tag to a plastic rod, a wireless pen is implemented which enables drawing in the air by using a program like Paint in Windows. Simulated results show that the resolution of the tag positioning in the system is in the order of 3mm in a distance equal to 0.5 meter in front of the array with few number of averaging over the received phase data. Using the system in practice reveals that it is easily possible to write and draw with this RFID pen. In addition it is argued how the system is totally immune to any counterfeit attempt for faked drawings by randomly changing the transmitting antenna in the array. This will make the system a novel option for human identity verification.</p> / QC 20100920

由於無線通訊相關應用持續蓬博發展，使得為關鍵零組件的射頻前端元件及模組相關產業於2006年開始獲利；以及化合物半導體於此領域的元件及模組為矽產業較難取以代，雖其製造流程相似，但其經營環境與矽產業有所不同，故值得深入探討其產業發展是否與矽產業有其不同之處。 本研究乃是針對化合物半導體產業於無訊通訊領域進行描述與分析來達成下列目的：第一、詳細地描述此產業現況及台灣廠商經營模式以提供各界參考；第二、在此產業發展已較為成熟時，檢視和分析此產業是否如矽產業採專業分工，以及找出影響產業垂直整合程度的關鍵因素為何；第三、運用產業矩陣進行產業分析，以供後續研究參考如何運用產業矩陣。 本研究採用司徒達賢教授所提出的產業矩陣分析法進行產業分析與描述，如此將能對此產業能有更系統化、周延且細緻地了解，並透過策略形態分析法深入了解各公司的策略構想為何，來協助釐清此產業較為重要的產業特性為何。 研究結果顯示，化合物半導體於無線通訊產業的IC設計與IC製造是否朝向專業分工，與IDM廠及專業晶圓廠的製程水準有關；以及在手機持續往輕薄短小、高頻率、以及3M(多頻、多模、多媒體)的方向發展下，對各價值單元的影響皆不同。

The objective of the proposed research is to design, implement, and characterize low-cost, lightweight front-end components and subsystems in the microwave domain through innovative packaging architectures for remote sensing applications. Particular emphasis is placed on system-on-package (SoP) solutions implemented in organic substrates as a low-cost alternative to conventional, expensive, rigid, and fragile radio- frequency substrates. To this end, the dielectric properties of organic substrates RT/duroid 5880, 6002 and 6202 are presented from 30 GHz to 70 GHz, covering most of the Ka and V radar bands, giving also a thorough insight on the uncertainty of the microstrip ring resonator method by means of the Monte Carlo uncertainty analysis. Additionally, an ultra-thin, high-power antenna-array technology, with transmit/ receive (T/R) functionality is introduced for mobile applications in the X band. Two lightweight SoP T/R array panels are presented in this work using novel technologies such as Silicon Germanium integrated circuits and microelectromechanical system switches on a hybrid organic package of liquid crystal polymer and RT/duroid 5880LZ. A maximum power of 47 dBm is achieved in a package with a thickness of 1.8 mm without the need of bulky thermal management devices. Finally, to address the thermal limitations of thin-film substrates of interest (liquid crystal polymer, RT/duroid 6002, alumina and Aluminum Nitride), a thermal assessment of microstrip structures is presented in the X band, along with the thermal characterization of the dielectric properties of RT/duroid 6002 from 20 ºC to 200 ºC and from 30 GHz to 70 GHz. Additional high-power, X-band technologies presented in this work include: a novel and compact topology for evanescent mode filters, and low-profile Wilkinson power dividers implemented on Aluminum Nitride using Tantalum Nitride thin-film resistors.

The performance of commercial Radio Frequency Identification (RFID) tags is primarily limited by present techniques used for tag antenna design. Currently, industry techniques rely on identifying the RFID tag application (books, clothing, etc.) and then building antenna prototypes of different configurations in order to satisfy minimum read range requirements. However, these techniques inherently lack an electromagnetic basis and are unable to provide a low cost solution to the tag antenna design process. RFID tag performance characteristics (read-range, chip-antenna impedance matching, surrounding environment) can be very complex, and a thorough understanding of the RFID tag antenna design may be gained through an electromagnetic approach in order to reduce the tag antenna size and the overall cost of the RFID system. The research presented in this thesis addresses RFID tag antenna design process for passive RFID tags. With the growing number of applications (inventory, supply-chain, pharmaceuticals, etc), the proposed RFID antenna design process demonstrates procedures to design tag antennas for such applications. Electrical/geometrical properties of the antennas designed were investigated with the help of computer electromagnetic simulations in order to achieve optimal tag performance criteria such as read range, chip-impedance matching, antenna efficiency, etc. Experimental results were performed on the proposed antenna designs to compliment computer simulations and analytical modelling.

For radio frequency energy transmission, the conversion efficiency of the receiver is decisive not only for reducing sending power, but also for enabling energy transmission over long and variable distances. In this contribution, we present a passive RF-DC converter for energy harvesting at ultra-low input power at 868 MHz. The novel converter consists of a reactive matching circuit and a combined voltage multiplier and rectifier. The stored energy in the input inductor and capacitance, during the negative wave, is conveyed to the output capacitance during the positive one. Although Dickson and Villard topologies have principally comparable efficiency for multi-stage voltage multipliers, the Dickson topology reaches a better efficiency within the novel ultra-low input power converter concept. At the output stage, a low-pass filter is introduced to reduce ripple at high frequencies in order to realize a stable DC signal. The proposed rectifier enables harvesting energy at even a low input power from −40 dBm for a resistive load of 50 kΩ. It realizes a significant improvement in comparison with state of the art solutions