Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2006. / John Papapolymerou, Committee Chair ; Joy Laskar, Committee Member ; John Cressler, Committee Member ; Alan Doolittle, Committee Member ; Clifford Henderson, Committee Member.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2009. / Traceability systems are capable of both tracking and tracing parts. They offer many benefits to an organisation from assisting with recall applications to monitoring the everyday workings of a production line or supply chain. There are numerous methods able to act as traceability systems but only a few can be regarded as automatic and unique identifiers. Automatic traceability of individual entities is the future. It is already widely used by a number of leading companies throughout different business sectors and wide mass adoption is imminent. At present, they are slightly more expensive than the simpler technologies but once mass produced, the cost will come down. To completely understand how traceability systems are implemented, practical experience is required. When starting a traceability project, there are a lot of different options. The different systems offer their own set of advantages and some don’t work in certain environments. It was for this reason that The Decision Making Model was developed to assist users through the difficult initial stages of traceability implementation (i.e. choosing the system most suitable to a particular environment). This model was programmed in Excel and supplies the user with a number of questions regarding the environment the system would work in as well as the user’s requirements. The answers to these questions help the user work through the different types of traceability options to eliminate unsuitable choices. The result is an easy to use program designed with the ability to be upgraded as the technologies evolve.

Low density plasmas are found throughout the known universe. Therefore, accurate diagnostic methods have implications for our understanding of a variety of topics, ranging from star formation to the semi conductor industry. Low density plasmas are ubiquitous in the material processing industry. However, measurements of the electron temperature and density, two of the most fundamental plasma properties, are not straightforward. In the laboratory, we create a low density, radio frequency, helium plasma with a bi-Maxwellian electron distribution, similar to those found in the semiconductor processing industry. We use optical emission spectroscopy to perform a non invasive measurement of the plasma conditions. We compare this to measurements obtained using a Langmuir probe, a commonly used invasive diagnostic. The optical emission spectroscopy is found to be insensitive to electron density but good agreement is found between the two techniques for values of the temperature of the hot electron component of the bi-Maxwellian. Plasmas created with high-intensity lasers are able to recreate conditions similar to those found during astrophysical events. This development has led to these condi- tions being explored in laboratories around the world. An experiment was performed at the Rutherford Appleton Laboratory in Didcot, UK, investigating the properties of supersonic turbulent jets. For the first time a magneto-optic probe was used to measure the magnetic field in a low-density supersonic turbulent plasma. The results were compared to measurements taken using a magnetic-induction probe. Good agreement was found between measurements of the magnetic field strength within the plasma; however, the magnetic power spectra differ. We attribute this to the dif- ference in integration length between the two measurements. Statistical properties of the velocity field are inferred from the magnetic field measurements, which compare favourably to astrophysical observations and hydrodynamic simulations.

Les produits issus des technologies Silicium tendent à exploiter au maximum les performancesdes transistors MOS tout en les soumettant à des profils de mission très agressifs du point de vuede la fiabilité. Les concepteurs sont ainsi à la recherche du meilleur compromis entre performanceet fiabilité.Historiquement, l’étude de la fiabilité du transistor MOS et le développement des modèlessous jacents ont été menés sur la base de contrainte de vieillissement statique. Avec le développementdes produits à hautes performances dans le domaine de la radiofréquence (RF), laquestion de la fiabilité pour ce type d’application se pose. Ainsi, une extension des modèles defiabilité doit être réalisée afin de quantifier le vieillissement des paramètres clés RF soumis àdes contraintes statiques mais également RF. C’est cette extension de la fiabilité des transistorsMOS dans le domaine RF qui constitue le sujet de ce travail de thèse.Dans ce manuscrit, le fonctionnement du transistor MOS est décrit et sa fiabilité est introduite.Les différents mécanismes de dégradation sont étudiés et leurs modèles associés décrits.Sont ensuite présentés un banc de mesure et une méthodologie nécessaire à l’étude du vieillissementdes transistors dans le domaine RF, ainsi qu’à l’extension des modèles de fiabilité audomaine RF. / Products using nowadays silicon technology are generally targeting aggressive specificationsand push the developers to determine the best compromise between performance and reliability.Main front-end degradation mechanisms are historically studied and modeled under static stressconditions and focus on the static MOS transistor parameters.With the development of product targeting high performances in the radio frequency (RF)domain, the reliability is becoming a first order concern. Thus an extension of the actual staticreliability models must be done to quantify the aging of key RF parameters under static andRF stress. In this context, this work focuses on the extension of the MOS transistor reliabilityregarding the study of RF parameters and also the application of RF stress.After describing the MOS transistor properties, the reliability aspect is introduced and theemphasis is put on the different degradation mechanisms and their associated models. Thisallows the development of an experimental setup and the required methodology to investigatethe device aging in the RF domain and to extend actual static models.

Este trabalho apresenta um estudo de medições de intensidades de campos elétrico em um centro cirúrgico, oriundos de fontes de radiofreqüência comerciais operando na cidade de Curitiba, no Paraná. Com o aumento da telefonia celular e, por conseguinte, de suas torres somando-se às antenas de televisões, rádios, rádios chamadas, redes de dados sem fio, internet por ondas de rádio, microondas, serviço de rádio da polícia, dos bombeiros, de rádio táxi, rádio amador, GPS, etc., o que acaba provocando um tipo de poluição eletromagnética “no ar”. Tal poluição pode trazer problemas tanto para o meio ambiente como para a saúde e, entre as tecnologias, possíveis interferências entre as mesmas podendo, por vezes, levar equipamentos a executarem funções imprevisíveis. Conhecer os valores de intensidade desses campos torna-se relevante, principalmente em um hospital onde vidas humanas podem estar a perigo quando conectadas a equipamentos susceptíveis a falhar em suas funções devido à presença desses campos. Os resultados obtidos neste trabalho são comparados com os recomendados pelas principais agências regulamentadoras. Após definido um hospital com o maior número de antenas em seu contorno, montou-se um setup de ensaios em seu centro cirúrgico, observando as distâncias mínimas possíveis entre paredes, teto, chão, luminária e entre as antenas. O setup encontra-se a 1920 cm na direção frontal e a 900 cm na direção lateral direita, posição essas que serviram como referência para o posicionamento do GPS no terraço para a obtenção das coordenadas geográficas. Os equipamentos utilizados foram: um receptor de sinais seletivos, um notebook com um software utilizado na operação do receptor e na aquisição dos dados, uma antena seletiva e um medidor de campo elétrico isotrópico. Foram selecionados 11 canais de televisões, 16 de rádios FM e 13 estações de rádio base (telefonia celular). Nos resultados das medições seletivas, os valores encontrados de 0,005 V/m comparados com as recomendações mais rigorosas (ONIR/Suíça) que é de 4,0 V/m ficando então os valores medidos 0,13% desse valor. Na faixa especifica da ONIR (900 & 1900), ou seja, GSM, este trabalho encontrou 0,0068 V/m ou 0,14% em relação aos valores preconizados por ela para as exposições ocupacionais e de 0,17% para o público em geral.Em questão dos equipamentos médicos obteve-se 1,75 V/m medido contra 3 V/m da norma NBR/IEC60601-1-2, ou seja, um campo medido de 58,33% menor do valor aconselhado. Este trabalho recomenda principalmente: adotar o Princípio da Precaução, que prevê medidas protetoras antecipadas perante as incertezas e/ou riscos desconhecidos, na operação dos transmissores; exigir que todas as instalações de transmissores tenham EIA/RIMA-EIV e; realizar periodicamente medições no contorno desses transmissores para verificar o incremento dos campos elétricos de outras fontes, que se somaram aos dos mesmos. / The aim of this paper is to present a study of measurement of the intensity of electric fields in a surgery room coming from radio frequency broadcasting sources located in Curitiba, Paraná. This is a result of an increase in cellular telephony and, consequently, of its transmission towers which, along with radio and TV antennas, radio service calls, wireless networks, internet connections by means of radio waves, microwave ovens, police and firefighters radio calls, radio taxi service calls, amateur radio service, GPS, and so on, produce a kind of electromagnetic pollution “in the air”. Such pollution might cause problems for the environment as well as for people’s health and there might even be some interference concerning the technologies themselves, which might cause equipment to perform unpredictable functions. Thus, it is important to become aware of the level of the intensity of these fields, especially concerning hospitals where human lives might be in danger when they depend on equipment that is likely to fail due to the presence of these magnetic fields. The results obtained in our study are compared to those recommended by the main regulating agencies. After selecting a hospital with the greatest number of antennas around, we built an experimental setup inside a surgery room, observing the minimum distance required between the walls, between the ceiling and the floor, light equipment, and among the antennas. The set up was located 1920 cm to the front and 900 cm to the right lateral position, which served as reference for placing the GPS equipment in order to obtain geographical coordinates. The equipment used involved a selective signal receiver, a notebook with a software used to receive signals and collect data, a selective antenna and isotropic electric field measurement equipment. Eleven TV channels, 16 FM radio stations and 13 radio-based stations (cellular telephony stations) have been selected. Concerning selective measurement, the result obtained was 0,005 V/m and, when compared to the most rigorous recommendation (ONIR/Switzerland) which is 4,0 V/m, the result was 0,13% distant from the one suggested. Concerning ONIR specific band (900 & 1900), that is, GSM, our study has found 0,0068 V/m or 0,14% when compared to the results recommended by ONIR for occupational exposure and 0,17% for people’s exposure in general. Concerning medical equipment, our study has found 1,75 V/m, compared to 3 V/m, expected according to NBR/IEC60601-1-2, that is, the measured field was 58,33% lower than the one recommended. Therefore, we recommend that some actions be taken such as: adopting the Precautionary Principle, which proposes anticipated protective measures in relation to uncertainties and/or unknown risks, for using broadcasting equipment; demanding that all broadcasting facilities observe Environmental Impact Assessment Studies/EIRs – Neighboring Community Environmental Impact Studies; and, finally, performing periodical measurement of the surroundings in order to check the increase in magnetic fields from other sources which produce magnetic field pollution.

Este trabalho apresenta um estudo de medições de intensidades de campos elétrico em um centro cirúrgico, oriundos de fontes de radiofreqüência comerciais operando na cidade de Curitiba, no Paraná. Com o aumento da telefonia celular e, por conseguinte, de suas torres somando-se às antenas de televisões, rádios, rádios chamadas, redes de dados sem fio, internet por ondas de rádio, microondas, serviço de rádio da polícia, dos bombeiros, de rádio táxi, rádio amador, GPS, etc., o que acaba provocando um tipo de poluição eletromagnética “no ar”. Tal poluição pode trazer problemas tanto para o meio ambiente como para a saúde e, entre as tecnologias, possíveis interferências entre as mesmas podendo, por vezes, levar equipamentos a executarem funções imprevisíveis. Conhecer os valores de intensidade desses campos torna-se relevante, principalmente em um hospital onde vidas humanas podem estar a perigo quando conectadas a equipamentos susceptíveis a falhar em suas funções devido à presença desses campos. Os resultados obtidos neste trabalho são comparados com os recomendados pelas principais agências regulamentadoras. Após definido um hospital com o maior número de antenas em seu contorno, montou-se um setup de ensaios em seu centro cirúrgico, observando as distâncias mínimas possíveis entre paredes, teto, chão, luminária e entre as antenas. O setup encontra-se a 1920 cm na direção frontal e a 900 cm na direção lateral direita, posição essas que serviram como referência para o posicionamento do GPS no terraço para a obtenção das coordenadas geográficas. Os equipamentos utilizados foram: um receptor de sinais seletivos, um notebook com um software utilizado na operação do receptor e na aquisição dos dados, uma antena seletiva e um medidor de campo elétrico isotrópico. Foram selecionados 11 canais de televisões, 16 de rádios FM e 13 estações de rádio base (telefonia celular). Nos resultados das medições seletivas, os valores encontrados de 0,005 V/m comparados com as recomendações mais rigorosas (ONIR/Suíça) que é de 4,0 V/m ficando então os valores medidos 0,13% desse valor. Na faixa especifica da ONIR (900 & 1900), ou seja, GSM, este trabalho encontrou 0,0068 V/m ou 0,14% em relação aos valores preconizados por ela para as exposições ocupacionais e de 0,17% para o público em geral.Em questão dos equipamentos médicos obteve-se 1,75 V/m medido contra 3 V/m da norma NBR/IEC60601-1-2, ou seja, um campo medido de 58,33% menor do valor aconselhado. Este trabalho recomenda principalmente: adotar o Princípio da Precaução, que prevê medidas protetoras antecipadas perante as incertezas e/ou riscos desconhecidos, na operação dos transmissores; exigir que todas as instalações de transmissores tenham EIA/RIMA-EIV e; realizar periodicamente medições no contorno desses transmissores para verificar o incremento dos campos elétricos de outras fontes, que se somaram aos dos mesmos. / The aim of this paper is to present a study of measurement of the intensity of electric fields in a surgery room coming from radio frequency broadcasting sources located in Curitiba, Paraná. This is a result of an increase in cellular telephony and, consequently, of its transmission towers which, along with radio and TV antennas, radio service calls, wireless networks, internet connections by means of radio waves, microwave ovens, police and firefighters radio calls, radio taxi service calls, amateur radio service, GPS, and so on, produce a kind of electromagnetic pollution “in the air”. Such pollution might cause problems for the environment as well as for people’s health and there might even be some interference concerning the technologies themselves, which might cause equipment to perform unpredictable functions. Thus, it is important to become aware of the level of the intensity of these fields, especially concerning hospitals where human lives might be in danger when they depend on equipment that is likely to fail due to the presence of these magnetic fields. The results obtained in our study are compared to those recommended by the main regulating agencies. After selecting a hospital with the greatest number of antennas around, we built an experimental setup inside a surgery room, observing the minimum distance required between the walls, between the ceiling and the floor, light equipment, and among the antennas. The set up was located 1920 cm to the front and 900 cm to the right lateral position, which served as reference for placing the GPS equipment in order to obtain geographical coordinates. The equipment used involved a selective signal receiver, a notebook with a software used to receive signals and collect data, a selective antenna and isotropic electric field measurement equipment. Eleven TV channels, 16 FM radio stations and 13 radio-based stations (cellular telephony stations) have been selected. Concerning selective measurement, the result obtained was 0,005 V/m and, when compared to the most rigorous recommendation (ONIR/Switzerland) which is 4,0 V/m, the result was 0,13% distant from the one suggested. Concerning ONIR specific band (900 & 1900), that is, GSM, our study has found 0,0068 V/m or 0,14% when compared to the results recommended by ONIR for occupational exposure and 0,17% for people’s exposure in general. Concerning medical equipment, our study has found 1,75 V/m, compared to 3 V/m, expected according to NBR/IEC60601-1-2, that is, the measured field was 58,33% lower than the one recommended. Therefore, we recommend that some actions be taken such as: adopting the Precautionary Principle, which proposes anticipated protective measures in relation to uncertainties and/or unknown risks, for using broadcasting equipment; demanding that all broadcasting facilities observe Environmental Impact Assessment Studies/EIRs – Neighboring Community Environmental Impact Studies; and, finally, performing periodical measurement of the surroundings in order to check the increase in magnetic fields from other sources which produce magnetic field pollution.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O objetivo deste trabalho foi desenvolver estratÃgias de monitoramento e automaÃÃo em sistemas de irrigaÃÃo utilizando sensores capacitivos FDR para coletar dados do conteÃdo de Ãgua no solo atravÃs de uma Rede de Sensores Sem Fio (RSSF). Os sensores capacitivos FDR foram desenvolvidos no Departamento de Engenharia AgrÃcola (DENA) da UFC. Foram utilizados neste trabalho 14 sensores capacitivos FDR e um deles passou por um processo de calibraÃÃo em laboratÃrio, onde foi sobreposta uma lÃmpada de 100 watts na amostra de solo indeformada para acelerar o secamento do solo. Esta calibraÃÃo derivou uma equaÃÃo do tipo potencial. A RSSF utilizada à formada por mÃdulos sensores capazes de comunicar-se entre si por rÃdio frequÃncia, possuindo um ponto de comunicaÃÃo final (estaÃÃo base). O sistema de RSSF foi constituÃdo de 7 mÃdulos sensores, 2 mÃdulos multihops e um mÃdulo mestre conectado ao computador. Cada mÃdulo sensor à constituÃdo pelos seguintes elementos: transceptor TRF 2.4 GHz da Laipac (alcance mÃximo de 150 m), memÃria, processador, bateria de 12 volts e dois sensores capacitivos FDR. A RSSF foi instalada em um campo cultivado por milho em estÃdio avanÃado de produÃÃo (30 DAS). Os sensores capacitivos FDR foram instalados em duas profundidades: 10 cm e 25 cm. Os dados dos mÃdulos sensores eram transmitidos ao mÃdulo mestre atravÃs dos 2 mÃdulos multihops. As respostas dos sensores capacitivos FDR foram coletadas pelos mÃdulos sensores todos os dias, pelo perÃodo da manhà e da tarde, e o tempo de irrigaÃÃo foi determinado com base na equaÃÃo de calibraÃÃo. As leituras foram coletadas antes e depois das irrigaÃÃes e o experimento durou aproximadamente 15 dias. Foi realizada uma validaÃÃo da calibraÃÃo em campo relacionando as respostas dos sensores capacitivos FDR em tempo real com a umidade volumÃtrica pelo mÃtodo padrÃo de estufa. A RSSF possibilitou que os sensores capacitivos FDR registrassem a variaÃÃo do teor de Ãgua durante os eventos de chuva e irrigaÃÃes. As comunicaÃÃes dos mÃdulos sensores foram bem sucedidas, apesar da altura das plantas e as ocorrÃncias das chuvas terem impedido em alguns momentos as transmissÃes. A equaÃÃo obtida em laboratÃrio subestimou os valores de umidade volumÃtrica real, obtida pelo mÃtodo direto, devido à temperatura que a lÃmpada incidiu na amostra de solo durante o processo de calibraÃÃo. A bateria dos mÃdulos sensores foi o fator mais limitante e requer ajuste no protocolo de comunicaÃÃo da RSSF par otimizar o consumo. A RSSF mostrou-se um sistema dinÃmico e preciso e pode, em conjunto com os sensores capacitivos FDR, auxiliar pesquisadores e produtores na tomada de decisÃo de irrigaÃÃo. / The goal of this study was to develop strategies for monitoring and automated irrigation systems using FDR capacitance sensors to collect data of water content in the soil through Wireless Sensor Network (WSN). The FDR capacitance sensors were developed in the Department of Agricultural Engineering (DENA) pertain UFC. Were used 14 FDR capacitance sensors and one of them went through a calibration process in the laboratory, witch was superimposed a 100-watt bulb in the soil sample undeformed to accelerate the drying soil. At the end of the calibration we obtained an equation potential model. The WSN is formed sensors nodes can communicate with each other by radio frequency having a communication end point (base station). The WSN system consisted of 9 sensors modules and a master module connected to the PC. Each sensor module consists of the following elements: 2.4 GHz transceiver TRF of company Laipac (maximum range 150 m), memory, processor, 12-volt battery and two FDR capacitance sensors. The WSN was installed in a field of maize crop in an advanced stage of production (30 DAS). The FDR capacitance sensors were installed at two depths: 10 cm and 25 cm. The data from the sensor modules were transmitted to the master module through the 2 modules multihops. The responses of the FDR capacitance sensors were collected every day at the morning and afternoon, and the time of irrigation was determined based on the calibration equation. The responses of the FDR capacitance sensors obtained by WSN were collected before and after irrigation and the experiment lasted 15 days. We performed a validation of the field calibration relating the responses of the FDR capacitance sensors in real time with the water content by gravimetric method. The WSN enabled FDR capacitance sensors recorded the variation of water content during the events of rainfall and irrigation. The communications of sensors modules have been successful, despite the height of plants and occurrences of rainfall have impeded some transmissions. The equation obtained in laboratory underestimated the true values water content obtained by the direct method, due to the temperature that the light bulb emitted on the soil sample during the calibration process. The battery of the sensor modules was the most limiting factor and requires adjustment in the communication protocol of WSN to optimize consumption. The WSN was dynamic and accurate and may, in partnership with FDR capacitance sensors, help researchers and producers in decision-making irrigation.

The Swedish Transportation Administration started an initiative to create a new e-infrastructure for the railroad sector in Sweden. The purpose is to follow the movement of railroad vehicles on the railway tracks and enhance logistics aspects of the transportation of goods by train. The Swedish initiative works as a pilot project for the railroad sector in the EU and if successful the e-infrastructure could be rolled out in the entire EU. It is a rare opportunity to be a part from the beginning of the creation of such a potential large scale e-infrastructure. The aim of this thesis is to provide advice early in the development process to aid in the success of the design and creation on the e-infrastructure. In the doing of this we will need to evaluate the areas: (1) the current state of the e-infrastructure, (2) the usefulness of the EPCGlobal standard for this e-infrastructure and (3) the usefulness on established e-infrastructures design principles. As a result of the thesis we have provided advice to enhance the design and implementation of the e-infrastructure, also advice is given on how to make the EPCGlobal standard’s more compatibility with the transportation sector. We have found the design principles by Hanseth & Lyytinen (2004) and Eriksson & Ågerfalk (2010) useful for the evaluation of the e-infrastructure. We also advocate that new design principles should be created to encompass the new concept of Internet of Things in e-infrastructures.

The growing demand for wireless communication systems is driving the integration of radio frequency (RF) front-ends on the same chip with multi-band functionality and higher spectral efficiency. Microelectromechanical systems (MEMS) have an overarching applicability to RF communications and are critical components in facilitating this integration process. Among a variety of RF MEMS devices, piezoelectric MEMS resonators have sparked significant research and commercial interest for use in oscillators, filters, and duplexers. Compared to their bulky quartz crystal and surface acoustic wave (SAW) counterparts, MEMS resonators exhibit impressive advantages of compact size, lower production cost, lower power consumption, and higher level of integration with CMOS fabrication processes. One of the promising piezoelectric MEMS resonator technologies is the aluminum nitride (AlN) contour mode resonator (CMR). On one hand, AlN is chemically stable and offers superior acoustic properties such as large stiffness and low loss. Furthermore, CMRs offer low motional resistance over a broad range of frequencies (few MHZ to GHz), which are lithographically-definable on the same silicon substrates. To date, RF MEMS resonators (include CMRs) have been extensively studied; however, one aspect that was not thoroughly investigated is how to modulate/tune their equivalent parameters to enhance their performance in oscillators and duplexers. The goal of this thesis is to investigate various modulation methods to improve the thermal stability of the resonator, its “effective” quality factor when used in an oscillator, and build completely novel non-reciprocal components. Broadly defined, modulation refers to the exertion of a modifying or controlling influence on something, herein specifically, the resonator admittance. In this thesis, three categories of modulation methods are investigated: thermal modulation, force modulation, and external electronic modulation. Firstly, the AlN CMR’s center frequency can be tunned by the applied thermal power to the resonator body. The resonator temperature is kept constant (for example, 90 °C) via a temperature sensor and feedback control such that the center frequency is stable over the whole operation temperature range of interest (e.g. –35 to 85 °C). The maximum power consumption to sustain the maximum temperature difference (120 ºC in this thesis) between resonator and ambient is reduced to a value as low as 353 μW – the lowest ever reported for any MEMS device. These results were attained while simultaneously maintaining a high quality factor (up to 4450 at 220 MHz device). The feedback control was implemented by either analog circuits or via a microprocessor. The analog feedback control, which innovatively utilized a dummy resistor to compensate for temperature gradients, resulted in a total power consumption of 3.8 mW and a frequency stability of 100 ppm over 120 ºC. As for the digital compensation, artificial neural network algorithm was employed to facilitate faster calibration of look-up tables for multiple frequencies. This method attained a frequency stability of 14 ppm over 120 ºC. The second modulation method explored in this thesis is based on the use of an effective external force to enhance the 3-dB quality factor of AlN CMRs and improve the phase noise performance of resonator-based oscillators. The force modulation method was embodied in a two-port device, where one of the two ports is used as a one-port resonator and the other is driven by an external signal to effectively apply an external force to the first port. Through this technique, the quality factor of the resonator was boosted by 140 times (up to 150,000) and the phase noise of the corresponding oscillator realized using the resonator was reduced by 10 dBc/Hz. Lastly, a novel magnetic-free electrical circulator topology that facilitates the development of in-band full duplexers (IBFD) for simultaneous transmit and receive (STAR) is proposed and modeled. Fundamentally, a linear time-invariant (LTI) filter network parametrically modulated via a switching matrix is used to break the reciprocity of the filter. The developed model accurately predicts the circulator behavior and shows very good agreement with the experimental results for a 21.4 MHz circulators built with MiniCircuit filter and switch components. Furthermore, a high frequency (1.1 GHz) circulator was synthesized based on AlN MEMS bandpass filters and CMOS RF switches, hence showing a compact approach that can be used in handheld devices. The modulation frequency and duty cycle are optimized so that the circulator can provide up to 15 dB of isolation over the filter bandwidth while good power transfer between the other two ports is maintained. The demonstrated device is expected to intrinsically offer low noise and high linearity. The combination of the first two modulation methods facilitates the implementation of monolithic, temperature-stable, ultra-low noise, multi-frequency oscillator banks. The third modulation technique that was investigated sets the path for the development of CMOS-compatible in-band full duplexers for simultaneous transmit and receive and thus facilitates the efficient utilization of the electromagnetic spectrum. With the aid of all these three modulation approaches, the author believes that a fully integrated, multi-frequency, spectrum-efficient transceiver is enabled for next-generation wireless communications.

Master of Science / Department of Agricultural Economics / Ted C. Schroeder / Electronic animal identification systems are becoming more common in livestock auction markets because of increased numbers of cattle being electronically identified. More cattle are being individually identified because of increasing enrollment in marketing alliances and verification programs. Also, the National Animal Identification System (NAIS) has increased awareness and perhaps use of electronic identification. In this study, individual characteristics of livestock markets were analyzed to determine how they relate to a livestock market operator's views, concerns, and knowledge of the NAIS as well as adoption of RFID reading equipment. Investments in RFID tagging services and RFID reading equipment by livestock markets were estimated and price premiums associated with RFID tagged and preconditioned cattle were estimated. Data were from a national survey of livestock auction markets and cattle transaction data were obtained from three Kansas livestock markets. Auction markets that indicated they currently plan to add a RFID tagging service are likely to have more knowledge of the NAIS program standards, how to adopt the NAIS practices, and the probable costs involved. Managers of facilities that sell a large volume of livestock annually tend to have a higher level of understanding of how to adopt the NAIS practices and be more knowledgeable of the NAIS standards than operators of smallvolume facilities. Managers of markets that have operating RFID reader systems tend to be more understanding of how to adopt the NAIS practices and of costs associated with adopting the NAIS. Livestock market managers tend to be highly concerned that adoption of individual animal identification systems will adversely impact sale speed and tend to view the NAIS as a threat to their business. Large volume facilities, facilities that have registered their premises, and facilities that plan to add a RFID tagging service are more likely to adopt RFID reader systems. Economies of scale exist in RFID system adoption and RFID tagging services for auction markets. Preconditioned and RFID tagged cattle brought a significant premium at only one of three facilities where data were collected.