Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / In this thesis, I present and analyze two of the most fundamental constraints of Radio Frequency Identification Systems (RFID), power rectification and signaling. These two issues play an important role in the continuing development of RFID systems. A passive RFID tag draws power from the RF field created by an RFID reader and uses it to energize its circuitry. It does this by rectification of the reader's radiated RF field using rectifying circuitry. The power then available to the tag is dependent upon both the available field strength and the efficiency of the rectification process. One option for increasing the operating range of an RFID system without increasing the reader's field strength is to increase the efficiency of the tag's rectification structure. A major component of any rectification circuit is a diode type device and so, the first part of the thesis focuses on the design and implementation of a novel high efficiency Schottky Barrier Diode (SBD) on a standard CMOS process. The forward voltage drop of the SBD diode was investigated and analytic equations formulated considering the Schottky barrier drift region resistance and the contributions from the p⁺ guard-grid. A design procedure to minimize the drift region resistance for any blocking voltage was derived. The fundamental trade-off between the forward voltage and leakage current in the novel SBD concept was determined. Based on the critical review of the Schottky diodes fabricated in the first part, new structures of novel SBD were designed to address most of the open issues related to its reverse break-down voltage and series resistance. Detailed analysis of the important design parameters of the novel Schottky barrier diode were performed using HSPICE with the parameter set used in the calibration process. The novel structure was also compared to an alternative fabrication approach, specifically, a NMOS and PMOS gate-cross-connected bridge. The comparison shows that the novel structure provides a 10% higher figure of merit for power rectification. In the later part of the thesis, an analysis of circuit advantages enabled by the novel SBD is given. The circuit simulation showed that by utilizing the novel SBD the operating frequency of the circuit can be increased to the UHF region while maintaining approximately the same power efficiency as that achievable when using a discrete Schottky diode. This leads to the possibility of dramatic improvements in size, weight and cost of the RFID transponder circuits. Signaling also plays an important role in the development of RFID systems. The choice of signaling methods and protocols determines not only the spectrum bandwidth usage, but also the data throughput. Also with constantly changing standards and regulations, it is important to be able to characterize and optimize these issues. Therefore the second part of this dissertation presents the design, implementation and evaluation of a novel RFID data logging reader architecture based on software radio concepts. The system is designed to overcome the many challenges and exploit the advantages of performing real-time signal processing and data logging in an RFID environment. The proposed concept has a unique multi-band RFID tag reader platform and has been designed to read tags conforming to the Electronic Product Code (EPC ) specifications in both the HF and UHF frequency bands. The hardware architecture consists of a general purpose analogue front end up/down-converter for each band, followed by a software radio based architecture allowing easy adaptation to new frequencies and protocols if required. The last chapter presents the results of investigations conducted to determine the ability of the proposed reader architecture to communicate with tags in typical channel noise and environmental conditions present in an RFID operational environment. Studies of the effects of reader interference in multi-reader environments and the development of an anti-collision protocol signaling to address and mitigate those effects are also presented. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1222149 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2006

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / In this thesis, I present and analyze two of the most fundamental constraints of Radio Frequency Identification Systems (RFID), power rectification and signaling. These two issues play an important role in the continuing development of RFID systems. A passive RFID tag draws power from the RF field created by an RFID reader and uses it to energize its circuitry. It does this by rectification of the reader's radiated RF field using rectifying circuitry. The power then available to the tag is dependent upon both the available field strength and the efficiency of the rectification process. One option for increasing the operating range of an RFID system without increasing the reader's field strength is to increase the efficiency of the tag's rectification structure. A major component of any rectification circuit is a diode type device and so, the first part of the thesis focuses on the design and implementation of a novel high efficiency Schottky Barrier Diode (SBD) on a standard CMOS process. The forward voltage drop of the SBD diode was investigated and analytic equations formulated considering the Schottky barrier drift region resistance and the contributions from the p⁺ guard-grid. A design procedure to minimize the drift region resistance for any blocking voltage was derived. The fundamental trade-off between the forward voltage and leakage current in the novel SBD concept was determined. Based on the critical review of the Schottky diodes fabricated in the first part, new structures of novel SBD were designed to address most of the open issues related to its reverse break-down voltage and series resistance. Detailed analysis of the important design parameters of the novel Schottky barrier diode were performed using HSPICE with the parameter set used in the calibration process. The novel structure was also compared to an alternative fabrication approach, specifically, a NMOS and PMOS gate-cross-connected bridge. The comparison shows that the novel structure provides a 10% higher figure of merit for power rectification. In the later part of the thesis, an analysis of circuit advantages enabled by the novel SBD is given. The circuit simulation showed that by utilizing the novel SBD the operating frequency of the circuit can be increased to the UHF region while maintaining approximately the same power efficiency as that achievable when using a discrete Schottky diode. This leads to the possibility of dramatic improvements in size, weight and cost of the RFID transponder circuits. Signaling also plays an important role in the development of RFID systems. The choice of signaling methods and protocols determines not only the spectrum bandwidth usage, but also the data throughput. Also with constantly changing standards and regulations, it is important to be able to characterize and optimize these issues. Therefore the second part of this dissertation presents the design, implementation and evaluation of a novel RFID data logging reader architecture based on software radio concepts. The system is designed to overcome the many challenges and exploit the advantages of performing real-time signal processing and data logging in an RFID environment. The proposed concept has a unique multi-band RFID tag reader platform and has been designed to read tags conforming to the Electronic Product Code (EPC ) specifications in both the HF and UHF frequency bands. The hardware architecture consists of a general purpose analogue front end up/down-converter for each band, followed by a software radio based architecture allowing easy adaptation to new frequencies and protocols if required. The last chapter presents the results of investigations conducted to determine the ability of the proposed reader architecture to communicate with tags in typical channel noise and environmental conditions present in an RFID operational environment. Studies of the effects of reader interference in multi-reader environments and the development of an anti-collision protocol signaling to address and mitigate those effects are also presented. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1222149 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2006

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2006. / Thesis Advisor(s): Ha, Tri T. ; Su, Weilian. "December 2006." Description based on title screen as viewed on March 12, 2008. Includes bibliographical references (p. 55-56). Also available in print.

In a supply chain, a warehouse is a crucial component for linking all chain parties. Automatic identification and data capture (auto-ID) technology, e.g. RFID and barcodes are among the essential technologies in the 21st century knowledge-based economy. Selecting an auto-ID technology is a long term investment and it contributes to improving operational efficiency, achieving cost savings and creating opportunities for higher revenues. The interest in auto-ID research for warehouse management is rather stagnant and relatively small in comparison to other research domains such as transport, logistics and supply chain. However, although there are some previous studies that explored factors for the auto-ID selection decision in a warehouse environment, those factors (e.g., operational factors) have been examined separately and researchers have paid no attention to all key factors that may potentially affect this decision. In fact, yet there is no comprehensive framework in the literature that comprehensively investigates the critical factors influencing the auto-ID selection decision and how the factors should be combined to produce a successful auto-ID selection process in warehouse management. Therefore, the main aim of this research is to investigate empirically the auto-ID technology-selection process and to determine the key factors that influence decision makers when selecting auto-ID technology in the warehouse environment. This research is preceded by a comprehensive and systematic review of the relevant literature to identify the set of factors that may affect the technology selection decision. The Technology-Organisation-Environment (TOE) framework has been used as lens to categorise the identified factors (Tornatzky & Fleischer, 1990). Data were collected by conducting first a modified (mixed-method) two-round Delphi study with a worldwide panel of experts (107) including academics, industry practitioners and consultants in auto-ID technologies. The results of the Delphi study were then verified via follow-up interviews, both face-to-face and telephone, carried out with 19 experts across the world. This research in nature is positivist, exploratory/descriptive, deductive/inductive and quantitative/qualitative. The quantitative data were analysed using the statistical package for social sciences, SPSS V.18, while the qualitative data of the Delphi study and the interviews were analysed manually using quantitative content analysis approach and thematic content analysis approach respectively. The findings of this research are reported on the motivations/reasons of warehouses in seeking to use auto-ID technologies, the challenges in making an auto-ID decision, the recommendations to address the challenges, the key steps that should be followed in making auto-ID selection decision, the key factors and their relative importance that influence auto-ID selection decision in a warehouse. The results of the Delphi study show that the six major factors affecting the auto-ID selection decision in warehouse management are: organisational, operational, structural, resources, external environmental and technological factors (in decreasing order of importance). In addition, 54 key sub-factors have been identified from the list of each of the major factors and ranked in decreasing order of the importance mean scores. However, the importance of these factors depends on the objectives and strategic motivations of warehouse; size of warehouse; type of business; nature of business environment; sectors; market types; products and countries. Based on the Delphi study and the interviews findings, a comprehensive multi-stage framework for auto-ID technology selection process has been developed. This research indicates that the selection process is complex and needs support and closer collaboration from all participants involved in the process such as the IT team, top management, warehouse manager, functional managers, experts, stockholders and vendors. Moreover, warehouse managers should have this process for collaboration before adopting the technology in order to reduce the high risks involved and achieve successful implementation. This research makes several contributions for both academic and practitioners with auto-ID selection in a warehouse environment. Academically, it provides a holistic multi-stage framework that explains the critical issues within the decision making process of auto-ID technology in warehouse management. Moreover, it contributes to the body of auto-ID and warehouse management literature by synthesising the literature on key dimensions of auto-ID (RFID/barcode) selection decision in the warehouse field. This research also provides a theoretical basis upon which future research on auto-ID selection and implementation can be built. Practically, the findings provide valuable insights for warehouse managers and executives associated with auto-ID selection and advance their understanding of the issues involved in the technology selection process that need to be considered.

<p>Technologies for position sensing and identification are important to have in ubiquitous computing environments. These technologies can be used to track users, devices, and artefacts in the physical milieu, for example, locating the position of a cellular phone in av physical environment. The aim of this thesis was to survey and classify available technologies for location sensing and identification. </p><p>We have made a literature study on both commercial and research-oriented systems and technologies for use in indoor and outdoor environments. We compared the characteristics of the underlying sensing technologies with respect to physical size, sensing method, cost, and accuracy. We conclude the thesis with a set of recommendations to developers and discuss the requirements on future sensing technologies and their use in mobile devices and environments.</p>

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Technologies for position sensing and identification are important to have in ubiquitous computing environments. These technologies can be used to track users, devices, and artefacts in the physical milieu, for example, locating the position of a cellular phone in av physical environment. The aim of this thesis was to survey and classify available technologies for location sensing and identification. We have made a literature study on both commercial and research-oriented systems and technologies for use in indoor and outdoor environments. We compared the characteristics of the underlying sensing technologies with respect to physical size, sensing method, cost, and accuracy. We conclude the thesis with a set of recommendations to developers and discuss the requirements on future sensing technologies and their use in mobile devices and environments.

The project deals with a theoretical design of passive ultra-high frequency radio identification (UHF RFID) tag for the measurement of liquid levels. Liquid level has an influence on the input impedance of an RFID tag antenna. The changes of input impedance have been used to distinguish individual liquid levels. Furthermore, this project presents optimization methods for the highest efficiency of an UHF RFID tag in Matlab and it aims to design a suitable antenna within CST MICROWAVE STUDIO.

This thesis describes the basic principles of radio frequency identification, basic characteristics of patch antennas, the possibility of their feeding and design of planar antenna series. Are discussed, impedance matching options. The selected antenna arrays were realised, measuring their parameters was down and measured parameters was compared with simulation results.

No description available.