Dissertations / Theses on the topic 'SAW'

Passive sensors that vary its impedance per measured parameter may be used with surface acoustic wave (SAW) reflective transducers (SRT) for wireless acquisition of the measurand. The device is composed of two transducers, where one, which may be attached to an antenna, is used to launch the wave within the device substrate, and the other is where the sensor load is attached to. The latter is able to reflect the incident wave. How much power is reflected is determined by the attached sensor load. Amplitude variations as well as peak frequency variations of the SRT reflectivity response are explored in this thesis. SAW passive temperature sensors with an orthogonal frequency coded (OFC) time response were previously investigated and prove to be ideal for use in harsh environments. Each sensor is distinguishable from the other due to the OFC code embedded within its time response. However, this coding technique poses a difficulty in designing antennas for the sensor due to its inherently wide bandwidth, and capacitive, non-uniform input impedance. This work covers antenna design and testing for the 250MHz wireless temperature acquisition prototype with a 28% fractional bandwidth, and for the 912MHz system which has 10% fractional bandwidth. Apart from the tag, antennas for the transmitter and receiver were designed for 50 Ohm matching with the required bandwidth maintained. Wireless temperature acquisition runs for the 250MHz prototype were successfully performed and show good agreement with measurements made by a thermocouple. Since a transceiver for the 912MHz system is not complete, the performance of the antennas was gauged by observing the signal transmitted wirelessly by the SAW tag and by comparing this with the sensor time response measured directly by a vector network analyzer.<br>M.S.E.E.<br>School of Electrical Engineering and Computer Science<br>Engineering and Computer Science<br>Electrical Engineering MSEE

Little research has been done to determine the stress states developed in an industrial sawblade for various operating conditions. The stresses are developed from the forces generated during the cutting of materials, and also from the vibration of the sawblade. The difficulty of analyzing these stresses and vibrations results from the sawbladeâ s high speed of rotation, which make it difficult to instrument the sawblade for analysis. Stress and vibration can ruin the sawblade from loss of material properties due to heat build-up and fatigue failure. The sawblade industry raised natural frequencies away from the operating frequencies to overcome the vibrations. To raise the natural frequencies of the sawblades away from the operating frequencies, residual stresses have been intentionally induced in the sawbody. The residual stresses come from plastically deforming the sawbody with one or more concentric rings. Experts who determine the location, depth, and number of residual stress rings are called â saw doctorsâ . This thesis quantifies the residual stresses induced by saw doctors. Developing and evaluating finite element models of an industrial sawblade while undergoing the effects from rotating and cutting are also included in the thesis. In addition, the effects on the sawblades performance due to various numbers and lengths of expansion slots and sawblade tensioning are explored. Models of the sawblade are plastically deformed leaving residual stresses which are analyzed to determine the natural frequencies of the sawblade. The thesis quantifies the above mechanisms for a sawblade under the loads developed from rotation and a load case representing the cutting process. The work developed in this thesis is a first step toward characterizing the effects of specific mechanisms which can be used to design better, longer lasting sawblades.<br>Master of Science

Humanity has entered a new geologic age wherein our actions have become the dominant influence steering both climate and environment, now having entered a new era of mass extinction. Some scientist allege that half of the extant animal species have disappeared in the last forty years, while other scientific studies project that the remaining nine million species will again halve by the end of the century. Although extinction cycles are no stranger to this planet, this sixth iteration is unique in that is being driven primarily by human consumption. It has been claimed that in order to sustain our current level of consumption, we would need a planet 1.5-2 times the size of the one we currently inhabit. It is easy to dismiss our individual responsibility as stewards of this planet. New modes of thinking about and approaching conservation at a local level must be developed in order to stave off the impending destruction of any and all species. Our own future as a species is inexorably linked to the success of the ecosystems we inhabit; their success, too, is bound to the species that sustain them. While this essay may not offer any meaningful solutions to an impending cataclysm, it is my hope that it will at the very least elicit a desire to amend the way we think about animals, nature, and the urgent responsibility we need to take for our planet in order for both our species and the Earth’s other inhabitants to endure.

<p>The goal of this research was to investigate the use of fixed abrasive diamond wire saw machining with wood and foam ceramic materials. Fixed abrasive diamond wire saw machining was developed in recent years to allow for thin kerf slicing of advanced semiconductor materials. The main advantages of this machining technology for the use in wood machining are its thin kerf loss and unidirectional cutting capability.The design of cutting experiments using a spooled wire saw is presented. The first experiment tested the response of machining wood repeatedly with the same process parameters. The next experiments tested the effect of changing wire axial speed and saw rocking motion conditions for pine and oak wood materials. Finally, an experiment was designed to machine three types of foam ceramic materials. A data acquisition system was constructed and signal-processing techniques for removing noise were developed. The data collection system was used to record forces and certain machine parameters during wire cutting. The machined surfaces for the wood materials were measured to determine their roughness. A Scanning Electron Microscope was used to examine new and used wire as well as cutting debris to study the effects of wire wear. Finally, the results and the direction of future work in this area are discussed.<P>

Diese Dissertation beschäftigt sich mit der Entwicklung eines neuartigen Konzepts für Herstellung und Handhabung von Mikrofluidiksystemen auf der Basis akustischer Oberflächenwellen (SAW) sowie der Nutzung dieses Konzepts zur Fertigung anwendungsrelevanter Teststrukturen. Schwerpunkte sind dabei unter anderem eine hohe Leistungsbeständigkeit und Lebensdauer der Chipbauelemente und eine hohe technologische Flexibilität bezüglich Herstellung und Einsatz. Ausgehend von einer modularen Betrachtungsweise der Bauelemente wurden vielseitig einsetzbare, elektrisch-optimierte Interdigitalwandler entworfen, verschiedene Herstellungsvarianten für vergrabene Interdigitalwandler hoher Leistungsbeständigkeit auf piezoelektrischen Lithiumniobat-Substraten entwickelt und experimentell verifiziert, ein Sputterverfahren für amorphe SiO2-Dünnschichten hoher Qualität optimiert und eine Federstiftkontakt-Halterung entworfen. Durch Kombination dieser Technologien wurden SAW-Bauelemente für die mikrofluidische Aktorik mit hoher Performance und Reproduzierbarkeit entworfen, charakterisiert und beispielhaft für das elektroakustische Zerstäuben von Fluiden und das Mischen in Mikrokanälen eingesetzt.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2009<br>Made available in DSpace on 2012-10-24T15:25:49Z (GMT). No. of bitstreams: 1 275380.pdf: 16310547 bytes, checksum: 855fe7a3dd6023cf5f2ba4cb4b9333dc (MD5)<br>Este trabalho objetiva estudar sensores de temperatura sem fio baseados na tecnologia SAW (Surface Acoustic Wave - ondas acústicas superficiais). Os sensores SAW utilizados são baseados na sensibilidade dos parâmetros de propagação de ondas SAW em um substrato piezelétrico encapsulado em um circuito integrado. Estes sensores dispensam alimentação e podem ser interrogados à distância, sem fio. O conhecimento dos parâmetros do sensor é necessário para possibilitar o projeto de um interrogador para com ele formar um sistema de medição. Foi utilizado um único modelo de sensor, que opera na faixa de frequência de 433 MHz, com faixa de medição de (0 a 120) °C. Para a avaliação, foram utilizados equipamentos de radiofrequência ligados através de cabos e interface de conectores, exigindo o emprego de técnicas específicas para desacoplá-los, pois interferem significativamente no resultado das medições. Os critérios de avaliação do sensores se basearam nos diferentes indicadores de ressonadores e a comparação com sensores convencionais de temperatura. Chegou-se à conclusão de que a interface de comunicação entre equipamentos e dispositivo sob teste é muito relevante, alterando de forma significativa os resultados. Também concluiu-se que os sensores SAW tem resposta linear e comportamento estável com o tempo.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2004.<br>Thesis documentation sheet inserted. Appendix reprints four papers and manuscripts, three co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

This thesis concentrates on the interaction between SAWs (surface acoustic wave) and low-dimensional systems studied using optical techniques. In particular SAW-driven luminescence from a lateral <i>p-n</i> junction is demonstrated. The lateral <i>p-n</i> junction is formed by molecular beam epitaxy regrowth on a patterned GaAs substrate. Silicon is used as an amphoteric dopant to create a high mobility two-dimensional electron gas on flat (100) planes and a two-dimensional hole gas on angled (311)A facets. A lateral <i>p-n</i> junction is formed at the interface between these planes. SAWs with a frequency of ~1 GHz are generated using an interdigitated transducer. When a continuous radio frequency (RF) signal is used to excite the transducer, SAW-driven light emission from the <i>p-n</i> junction is demonstrated by peaks in the current/light emission at the resonant frequency of the transducer. To investigate the nature of the luminescence further, short RF pulses are used to drive the transducer. The short pulses temporally isolate the SAW-driven light emission from any emission due unwanted pick-up of the free space electromagnetic wave. In the final section the modulation of the emission energies of a single self-assembled quantum dot by a SAW is investigated. The compression and expansion of the crystal due to the strain wave causes the energy of the dot lines to oscillate around their equilibrium values. The shape of the SAW broadened emission lines was seen to depend on the nature of the transition in the dot offering an alternative way of identifying charged and neutral species in this sample. The modulation of the dot energy levels by the SAW is used to control the time of photon emission from the system.

Ultra&#150;wideband (UWB) communication new technology with ability to share the FCC allocated frequency spectrum, large channel capacity and data rate, simple transceiver architecture and high performance in noisy environments. Such communication advantages have paved the way for emerging wireless technologies such as wireless high definition video streaming, wireless sensor networks and more. This thesis examines orthogonal frequency coded surface acoustic wave (SAW) correlators for use in advanced UWB communication systems. Orthogonal frequency coding (OFC) and pseudo-noise (PN) coding provides a means for UWB spreading of data. The use of OFC spectrally spreads a PN sequence beyond that of CDMA because of the increased bandwidth; allowing for improved correlation gain. The transceiver approach is still very similar to that of the CDMA approach but provides greater code diversity. Use of SAW correlators eliminates many of the costly components that are needed in the IF block in the transmitter and receiver, and reduces much of the signal processing requirements. The OFC SAW correlator device consists of a dispersive OFC transducer and a wideband output transducer. The dispersive filter was designed using seven contiguous chip frequencies within the transducer. Each chip is weighted in the transducer to account for the varying conductance of the chips and to compensate for the output transducer apodization. Experimental correlator results of an OFC SAW correlation filter are presented. The dispersive filter is designed using seven contiguous chip frequencies within the transducer. SAW correlators with fractional bandwidth of approximately 29% were fabricated on lithium niobate (LiNbO3) having a center frequency of 250 MHz and the filter has a processing gain of 49. A coupling of modes (COM) model is used to predict the experimental SAW filter response. Discussion of the filter design, analysis and measurements are presented. Results are shown for operation in a matched filter correlator for use in an UWB communication system and compared to predictions.<br>M.S.E.E.<br>School of Electrical Engineering and Computer Science<br>Engineering and Computer Science<br>Electrical Engineering MSEE

During past two decades a variety of SAW based wireless sensors were invented and research is still in progress. As different frequencies, varied bandwidths, coding techniques and constantly changing post processing algorithms are being implemented, there is a constant need for a universal and adjustable synchronous communication system able to interrogate new generations of SAW sensors. This thesis presents the design of a multiple FPGA based communication system with an operational frequency range of 450MHz-2.2GHz capable of producing user programmed modulated signal. The synchronous receiver is designed to have interchangeable chip, replacement of which would allow adjustment of the receiver's bandwidth. Within this paper the performance of the system is only evaluated at 915MHz centered 20MHz bandwidth region. An OFC temperature sensor was interrogated. Post-processing algorithms, measurement results, and proposals for the future use of the system are presented. Detailed overview of the structure and performance of every functional block along with design considerations are analyzed. Previously designed Matlab based software was adapted for post processing of the received signal. New software with simplified GUI was designed for programming of the desired signal.<br>ID: 031001517; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Donald C. Malocha.; Title from PDF title page (viewed August 16, 2013).; Thesis (M.S.E.E.)--University of Central Florida, 2012.; Includes bibliographical references (p. 73-74).<br>M.S.E.E.<br>Masters<br>Electrical Engineering and Computing<br>Engineering and Computer Science<br>Electrical Engineering

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>AGÊNCIA NACIONAL DE PETRÓLEO<br>Os sistemas micro eletromecânicos são dispositivos na escala dos micras que combinam estruturas mecânicas com circuitos elétricos, e são usados como sensores ou atuadores. Dentro destes dispositivos, estão os de onda superficial acústica (SAW em inglês) que usam variações na velocidade ou percurso de propagação da onda para fazer a detecção da variável a medir. Uma aplicação importante em processos químicos, é no acondicionamento de ambientes, monitorando a umidade. Para isso um sensor SAW comprado, foi coberto em sua superfície com uma camada de um polímero absorvente de vapor de agua. No qual o aumento na massa do polímero na superfície diminui a velocidade da onda. Por tanto o PolyVinyl Álcool foi escolhido para absorver o vapor de agua e foi preparado com 5.6 wt por cento, para ser depositado por meio de spin coating. Então uma serie de experimentos foram feitos numa câmara climática variando tanto a umidade como a temperatura, com o fim de avaliar o comportamento do sensor medindo a sua variação da frequência. Estes resultados foram comparados com um modelo analítico e uma simulação por elementos finitos. O modelo analítico foi presentado por Sielman, o qual determina como muda a densidade e espessura no polímero com a umidade. Estes valores foram substituídos na equação de Wohltjen que dá a variação da frequência de um SAW devido a absorção de gases. Em quanto a simulação por elementos finitos foi feita em Comsol Multiphysics achando a frequência para a qual o SAW ressona, com o aumento da densidade na camada acima do SAW para as umidades inseridas.<br>Micro electromechanical systems (MEMS) are devices that combine mechanical structures with electrical circuits at the micro scale, to function as sensors or actuators. One type of MEMS are the surface acoustic waves (SAW) devices, which uses the surface wave velocity or propagation path variations to measure the variable of interest. One important application in chemical processes is related to environment condition control, specifically humidity measurement. With that purpose, a commercial SAW was purchased and coated with a polymer layer in its surface. The PolyVynil Alcohol (PVA) was chosen to be the sensing layer in the SAW due to water vapor absorption properties, that increases the mass over the surface and decrease the wave velocity, leading to sense this humidity changes. 5.6wt per cent PVA solution was prepared and deposited through spin coating. Therefore, a series of tests were carried out in a climatic chamber, varying the humidity and temperature conditions, with the aim to analyze the sensor behavior by measuring its frequency shift. These results were compared with an analytical model and a finite element simulation. The analytical model presented by Sielman determines how the polymer density changes with humidity. These density values were inserted into the Wohltjen equation, which gives the frequency shift of the SAW due to gas absorption. Regarding the finite element simulation, it was carried out in the Comsol Multiphysics software, by solving the different resonating frequencies as a function of the increase in the polymer density due to the insets of humidity values.

A multifunctional strain sensor based on Surface Acoustic Wave (SAW) Orthogonal Frequency Coding (OFC) technology on a Langasite substrate has been investigated. Second order transmission matrix models have been developed and verified. A new parameterizable library of SAW components was created to automate the layout process. Using these new tools, a SAW strain sensor with OFC reflectors was designed, fabricated and tested. The Langasite coefficients of velocity for strain (γS = 1.699) and Temperature (γT = 2.562) were experimentally determined. The strain and temperature characterization of this strain sensor, along with the coefficients of velocity, have been used to demonstrate both the ability to sense strain and the capability for temperature compensation. The temperature-compensated SAW OFC strain sensor has been used to detect anomalous strain conditions that are indicators of fastener failures during structural health monitoring of aircraft panels with and without noise on a NASA fastener failure test stand. The changes in strain that are associated with single fastener failures were measured up to a distance of 80 cm between the sensor and the removed fastener. The SAW OFC strain sensor was demonstrated to act as an impact sensor with and without noise on the fastener failure test stand. The average measured signal to noise ratio (SNR) of 50, is comparable to the 29.1 SNR of an acoustic emission sensor. The simultaneous use of a high pass filter for impact detection, while a low pass filter is used for strain or fastener failure, demonstrates the multifunctional capabilities of the SAW OFC sensor to act as both as a fastener failure detector and as an impact detector.

Thesis (M.S.) -- University of Maryland, College Park, 2008.<br>Thesis research directed by: Dept. of Chemical and Biomolecular Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

The cutting links on chainsaws needs to be sharpened regularly to retain its sharpness. The most effective way is to use a machine wheel grinder. However, due to high friction there is a high risk of tempering the steel and damaging the sustainability to wear, resulting in a dull cutting edge. In order to develop a grinding method that produces a good result every time, a series of parameters were tested in order to determine which combination of these generated the best grinding results. With all parameters established the results shows that the attributes of each grinding wheel are the main parameter controlling the grinding result. This project investigates the attributes of different grinding wheels and their impact on grinding results. By comparing the energy each grinding wheel uses to perform the same amount of work, each grinding wheels suitability is rated based on its performance.   The calculations and the results from the analyses and tests show which of the grinding wheels performed the work with the lowest amount of increased energy.

De tous temps, l'amélioration des moyens de guérison et de prévention des maladies a constitué un enjeu majeur de nos sociétés. Les possibilités offertes désormais par les technologies modernes ont permis de multiplier le nombre d'applications médicales mais toutes ces pratiques nouvelles ont un impact dans le domaine de l'expérimentation animale et impliquent aussi un suivi sanitaire à grande échelle. Le travail présenté dans cette thèse a pour but de moderniser la surveillance de l'état de santé des souris de laboratoire, et s'inscrit dans un projet collaboratif entre le LEAT et TIRO-MATOs. L’objectif est la conception d’un système capable de faciliter ce suivi au quotidien. Pour cela, la conception d'une antenne à 433MHz, connectée à un capteur de température, implantable dans une souris et intégrant notamment l'impact de l'environnement biologique a tout d’abord été étudiée. Après caractérisation des éléments obtenus, la faisabilité d’un système de géolocalisation est présentée. Afin de disposer également de la capacité d’identification des sujets, cette étude s’est poursuivie à 868 MHz (standard RFID). Dans cette partie, l’antenne interrogatrice placée sous la cage, a été plus particulièrement étudiée. Afin de comparer les différentes antennes obtenues, des mesures de puissance récupérées par le lecteur (RSSI) sont réalisées, utilisant pour cela des phantoms de souris spécialement mis au point pour cette étude. Les conclusions tirées par comparaison notamment avec les résultats de phantoms numériques ont permis de concevoir un dispositif de diversité à 4 antennes et de le tester en présence de un à quatre phantoms dans quatre différentes zone de la cage<br>The improvement of the methods of cure and prevention of diseases has always constituted a major objective in our societies. The possibilities offered by modern technologies allow the multiplication of the number of medical applications but all these new practices have an impact on pre-clinical animal studies which require a large-scale health status follow-up. This work, which aims at modernizing the supervision of laboratory mice in an animal facility, is a collaborative project between the LEAT and TIRO-MATOs labs. The objective is the design of a system allowing to facilitate this follow-up for the researchers while leading to new research areas. Thus, we first studied the conception of an antenna working at 433MHz, connected to a mouse implanted temperature sensor, taking also into account the biological environment impact. After having characterized the obtained elements, the feasibility of a localization system has been studied. In order to identify several mice within a cage, the study has focused on using an UHF RFID (Radio Identification Frequency) standard (868 MHz). In this part, a reader antenna placed under the cage has been investigated. Different solutions have been proposed and compared thanks to the received power (RSSI level) recorded by the reader. For that purpose, mice “phantoms” have been specifically developed. The comparison of the different results obtained particularly with numerical mice “phantoms”, led to the conception of a reading diversity system composed of 4 antennas. This last system allows to detect the presence of up to four phantoms within a cage divided into four zones

This dissertation provides a comprehensive methodology for accurate analysis and design of miniaturized radio frequency (RF) surface acoustic wave (SAW) duplexer package. Full-wave analysis based on the three dimensional (3-D) finite element method (FEM) is successfully applied to model the package. The die model is obtained by combining the acoustics and die busbars parasitics models. The acoustics model is obtained using the coupling-of-models (COM) technique. The die busbars, bonding wires and printed circuit board (PCB) are modeled using full-wave analysis. After that, the models of package, die, and bonding wires are assembled together to get the total response. To take into account the mutual couplings, the methodology is extended to model the package, die busbars, and bonding wires together. The advantages and disadvantages of the methodology are also discussed. Based on the methodology, the Korea personal communication system (KPCS) duplexer is analyzed and designed. The isolation of KPCS duplexer package is significantly improved by redesigning inner ground plane, bonding wire scheme and ground via. A KPCS duplexer package is designed and excellent transmitter to receiver isolation in the transmission band is achieved. Simulation and measurement results are compared, and excellent agreement is found. Although we focus on investigating the methods to improve the isolation, the passband performance is also improved. The methodology is also successfully used for flip chip duplexer. The simulation results from our assembling method match the measurement results very well. Optimization method is applied to improve the transmit band isolation. With the new package and die design, the transmit band isolation can be improved from -53.6 dB to -65.2 dB. Based on the new package, the effect of the Rx ground trace on the isolation is investigated and the transmit band isolation can achieve -67.3 dB with the modification of the Rx ground trace. The technique developed in this dissertation reduces the design cycle time greatly and can be applied to various RF SAW device packages.<br>Ph.D.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering

Thesis (Ph. D.)--University of California, San Diego, 2009.<br>Title from first page of PDF file (viewed June 10, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 126-133).

The operating speed of circular saws is limited by the natural frequencies of the saw. Current methods in industry of increasing the natural frequency of the saw include pretensioning, where tensile forces are introduced into the saw. The integration of shape memory alloys, to provide tensioning to the saw, is investigated as an alternative or complement to pretensioning. To better model the saw, a finite element model is compared to current software for steel saws, CSAW, a software program that calculates frequencies for stiffened circular saws. Using CSAW and the finite element method, the results are compared and the finite element model is validated for steel saws. The validated model is then used to simulate and test circular saw blade designs incorporating shape memory alloys. The designs are found to provide similar stability characteristics to tensioned steel saws.<br>La vitesse opérationnelle des scies circulaires est limitée par ses fréquences de vibration naturelles. La prétension, qui est l'inclusion ou l'introduction de contraintes de tension au périphérique de la scie, est une méthode couramment utilisée dans le milieu industriel qui permet de stabiliser la scie. L'intégration des alliages à mémoire de forme à la scie, qui produiront des contraintes en tension comparables à la prétension, est proposée. Un modèle d'élément fini ayant été validé en le comparant au logiciel de stabilité de scie, CSAW pour les scies d'acier, est utilisé pour faire la simulation et la validation du concept de la scie aux alliages à mémoire de forme. Nous démontrons ainsi que ce concept de scie est comparable à la méthode de pretension appliquée aux scies d'acier.

Abstract Self-Interference Cancellation Techniques for SAW-less Transceivers Saheed A. TIJANI The adoption of mobile wireless communication technologies ranging from GSM to the future 5G radios has continuously required increased data rates and quality of service and, in general, the miniaturization of devices and costs reduction. At this contemporary world, one cannot imagine life without wireless communications. Practically, our mobile smartphones have become our daily companion which are used for different tasks ranging from writing emails, making both voice and video calls, live program streaming, IOT (internet of things) applications, and endless tasks we could not imagine in the past. The present wireless radios have inevitably off-chip passive components like the SAW filters, Duplexer and high Q filters. These filters are needed to filter out unwanted signals such as large CW (continuous wave) blockers and self-interference signals (or TX leakage) by about 50dB. The fact that recent mobile wireless technologies like LTE and the future 5G propose the adoption of MIMO and carrier aggregation capable of managing multi bands in the system architecture, it implies that the number of antennas, external fixed frequency filters and on-chip building blocks would increase further. Hence, a huge increase in the form factor and cost will result unless some actions are taken. This thesis proposes two innovative self-interference cancellation(SIC) techniques for transceivers while eliminating the use of external SAW filters/ Duplexers. This dissertation compares active and passive SIC techniques where the passive SIC technique has been fully integrated. The concepts, analysis and results are presented. These approaches specifically suppress self-interference while improving the linearity of the receiver with the benefit of low form factor, reduced cost and relaxed linearity requirements for the front-end building blocks. In the concluding part of the thesis, a control loop algorithm is proposed to optimize IIP2 of LNA (in a duplexer/SAW-less receiver suitable for TV white space applications) during process corners and temperature variations.<br>Abstract Self-Interference Cancellation Techniques for SAW-less Transceivers Saheed A. TIJANI The adoption of mobile wireless communication technologies ranging from GSM to the future 5G radios has continuously required increased data rates and quality of service and, in general, the miniaturization of devices and costs reduction. At this contemporary world, one cannot imagine life without wireless communications. Practically, our mobile smartphones have become our daily companion which are used for different tasks ranging from writing emails, making both voice and video calls, live program streaming, IOT (internet of things) applications, and endless tasks we could not imagine in the past. The present wireless radios have inevitably off-chip passive components like the SAW filters, Duplexer and high Q filters. These filters are needed to filter out unwanted signals such as large CW (continuous wave) blockers and self-interference signals (or TX leakage) by about 50dB. The fact that recent mobile wireless technologies like LTE and the future 5G propose the adoption of MIMO and carrier aggregation capable of managing multi bands in the system architecture, it implies that the number of antennas, external fixed frequency filters and on-chip building blocks would increase further. Hence, a huge increase in the form factor and cost will result unless some actions are taken. This thesis proposes two innovative self-interference cancellation(SIC) techniques for transceivers while eliminating the use of external SAW filters/ Duplexers. This dissertation compares active and passive SIC techniques where the passive SIC technique has been fully integrated. The concepts, analysis and results are presented. These approaches specifically suppress self-interference while improving the linearity of the receiver with the benefit of low form factor, reduced cost and relaxed linearity requirements for the front-end building blocks. In the concluding part of the thesis, a control loop algorithm is proposed to optimize IIP2 of LNA (in a duplexer/SAW-less receiver suitable for TV white space applications) during process corners and temperature variations.

The theme of this thesis is design of horizontal band saw and it deals with problems of existing machines on market. Main goal of work is to create effective design and solution of problematic parts, with emphasis on modernization of band saws, which ones processing raw tree trunks.

Neste trabalho apresentaremos os procedimentos para a confecção de substratos de LiNbO3 para dispositivos OAS (Ondas Acústicas Superficiais). Assim como a construção de linhas de atraso, caracterização elétrica e pelo método de \"Laser Probe\". No procedimento experimental, inicialmente descreveremos os métodos e cuidados para a preparação dos substratos do monocristal de LiNbO3 produzido nos laboratórios do Grupo de Crescimento de Cristais do DFCM - IFQSC - USP. Para serem utilizados em linhas de atraso com freqüência central de operação de 70 MHz. Na segunda etapa, descreveremos a construção dos transdutores, o encapsulamento e a caracterização elétrica das linhas de atraso. A caracterização elétrica consta das medidas de impedância das portas de entrada e saída, e da medida de transmissão em um espectro de freqüência do dispositivo OAS. Finalmente, para a caracterização dos substratos confeccionados e util1zados nas linhas de atraso, construímos um sistema óptico, \"Laser Probe, que nos permite medir a velocidade e determinar o campo da onda acústica superficial sobre esses substratos. Apresentamos através do conhecimento do campo acústico, o espalhamento, o desvio de feixe acústico com relação ao alinhamento dos transdutores e as frentes de ondas superficiais em regiões do substrato. Resultados das medidas de perda intrínseca (6 dB) por linha de atraso e o espectro de transmissão dos dispositivos OAS foram apresentados. Sendo a última medida apresentada em comparação com a medida de transmissão da caracterização elétrica<br>In this work a procedure is presented for fabricating LiNbO3 substrates for Surface Acoustic Wave (SAW) devices. Also described is the construction of SAW delay lines which are characterized using electrical and acoustic-optical methods. Firstly, the experimental methods for producing LiNbO3 single crystal substrates for operation at 70 MHz are described in detail. The single crystals were grown in the crystal growth laboratory of DFCM_IFQSC. Secondly, the techniques for building the transducers are discussed including the encapsulation. The delay lines are then characterized electrically by measuring the impedance of transducers and also the transmission frequency spectra of the SAW devices. Finally, for the characterization of substrates used in delay lines, a laser probe technique was developed, which allows the propagation velocities to be measured. Surface acoustic wave fields in these substrates are then determined making it possible to obtain the scattering, beam steering acoustic and the surface wave fronts in the substrates regions. As an application, results of intrinsic loss (6dB) and pass band measurements in the delay line are presented. These results are found to be in good agreement with previously published data

Les travaux présentés dans ce manuscrit concernent la réalisation et la caractérisation d’un capteur de gaz à base de dispositifs à ondes élastiques de surfaces, SAW (Surface Acoustic Wave). Pour obtenir et exploiter de telles ondes, deux transducteurs inter-digités (IDT), l’un servant d’émetteur et l’autre de récepteur, sont déposés sur un substrat piézoélectrique. Une tension alternative appliquée aux bornes de l’IDT émetteur génère une onde se propageant le long du substrat. Lorsque cette onde arrive sur l’IDT récepteur, elle est convertie en tension électrique. A partir de ce dispositif, la spécificité du capteur est obtenue par l’ajout d’une couche sensible sur le chemin de propagation de l’onde, entre les deux IDTs. L’adsorption du gaz sur la couche sensible perturbe la propagation de l’onde et modifie ainsi sa vitesse et son amplitude. La structure du capteur développé et caractérisé au cours de cette thèse est la suivante : Polyaniline/ZnO/Quartz. Le substrat bicouche ZnO/Quartz pour une direction de propagation particulière (90°) constitue la partie génératrice d’ondes de Love et la polyaniline, polymère fonctionnalisable est utilisée en tant que couche sensible. La structure génératrice d’ondes a été entièrement réalisée en salle blanche avec notamment l’optimisation des paramètres de dépôt du film de ZnO par pulvérisation réactive RF magnétron et la photolithographie des IDTs. Elle a ensuite été étudiée et caractérisée, avant et après dépôt de la couche sensible, par des mesures expérimentales confrontées aux estimations théoriques. Pour finir, nous avons procédé à des tests sous gaz (NO2, SO2 et éthanol) avec notre capteur. Nous avons ainsi pu montrer le potentiel d’utilisation de la structure Polyaniline/ZnO/Quartz en tant que capteur de gaz<br>The work presented in this book concerns the realization and characterization of a gas sensor based on surface acoustic wave (SAW) devices. To obtain and work with these waves, two interdigital transducers, one emitting and one receiving, are deposited on a piezoelectric substrate. An alternating input signal at the emitting IDT stimulates a wave that propagates along the substrate. At the receiving IDT, this wave is converted into electrical output signal. To obtain a gas sensor, a sensitive film is added in the path of the wave, between the IDTs. The gas adsorption on the sensitive film perturbs the wave propagation and modifies its velocity and amplitude. The sensor structure developed and characterized during this PhD thesis is the following : Polyaniline/ZnO/Quartz. The two layers ZnO/Quartz substrate, for a 90° propagating direction, generates the Love waves and the polyaniline, polymer that can be modified by functional groups is used as sensitive layer. The waves generating structure has been realized entirely in a clean room, especially with the optimisation of the ZnO films deposition by RF magnetron reactive pulverisation process and the photolithography of the IDTs. Then, this structure has been studied and characterized, before and after the sensitive layer deposition, with experimental measurements compared with theoretical estimations. Finally, we have made gas tests (NO2, SO2 and ethanol) with the sensor. In this way, we have shown that the Polyaniline/ZnO/Quartz structure can be used as gas sensor

Le micro-cavità optomeccaniche (OM) sono oggetto di intenso studio, come possibile fonte di nuove funzionalità, concetti e opportunità che vanno oltre la tecnologia standardin termini di propagazione, generazione ed elaborazione dei fononi a microonde al micro e nanoscala. In questo framework, l'interazione OM non lineare è oggetto di indagini approfondite, Il tipo di ricerca sopra riportato è altamente interdisciplinare, e si sposta lungo la frontiera di molti campi, come ad esempio i filtri a microonde per onde acustiche di superficie (SAW), fotonica, elettronica ed, inoltre, nanofisica e ottica quantistica. In particolare, alcuni recenti risultati sul raffreddamento dello stato fondamentale OM promettono un controllo coerente del movimento quantico di risonatori meccanici. Un esempio pertinente è fornito dal recente accoppiamento di un qubit superconduttore alle vibrazioni meccaniche di un risonatore piezoelettrico, ovvero risuonatori meccanici a microonde operati al limite quantico. Meccanismi fondamentali dei sistemi OM, come la pressione di radiazione e la forza elettrostrittiva esercitata da campi elettromagnetici sulla materia e, al contrario, modulazione fotoelastica dei campi elettromagnetici, sono responsabili delle forti interazioni che si verificano nelle cavità risonanti. In effetti, pressioni enormi possono agire nella regione della cavità a causa del fattori Q elevati raggiungibili sia per le modalità ottiche che meccaniche che coesistono nella cavità. Il meccanismo sopra descritto produce utili trasduzioni e attuazioni vibrazionali ai livelli di potenza da µ- a m-watt. Inoltre porta potenzialmente allo sviluppo di fonon laser e rivelatori. È probabile che tale sviluppo consenta l'elaborazione del segnale fononico a temperatura ambiente e l'integrazione di elementi fonetici su una piattaforma di silicio, in grado di generare nuovi modi di elaborare le informazioni. L'obiettivo finale è l'utilizzo di fononi, invece di elettroni, come vettori di informazione e la costruzione di un chip che possa lavorare a temperatura ambiente, analogamente al funzionamento di dispositivi basati su SAW, per applicazioni di filtraggio e rilevamento. I vantaggi di questa nuova tecnologia sono dati, ad esempio, dal possibile funzionamento ad alta frequenza e dal basso consumo energetico. Inoltre, rispetto all'azionamento nanoelettromeccanico puro, l'approccio ottico è meno sensibile ai problemi di discrepanza capacitiva e di impedenza. Alla luce di quanto sopra, la prima parte di questa tesi tratta dell'interpretazione teorica del fenomeno OM che si verifica nelle µ-cavità ad alto Q, con l'obiettivo di fornire un approccio affidabile e rigoroso per massimizzare le prestazioni di un generatore coerente di fononi. Se si considerara il futuro sviluppo della circuiteria OM, avere un metodo in grado di fornire sia l'esatta popolazione fononica generata in una data cavità e la valutazione delle forze ottiche e meccaniche che giocano il loro ruolo nell'interazione tra le due fisiche sarà di fondamentale importanza. Insieme al modello numerico sopra descritto, è stata realizzata anche un'applicazione intuitiva. La seconda parte di questa tesi si concentra sull'eccitazione ottica del generatore di fononi, che propone un design fatto di una lastra di Si che viene prima miscelata e poi inciso selettivamente, in modo che la coda evanescente del campo elettrico possa essere migliorata e, di conseguenza, il trasferimento di energia EM tra tale lastra e la cavità OM può essere massimizzato. Questa soluzione non solo garantisce migliori prestazioni rispetto al approccio standard in fibra ottica, ma è anche adatto per l'integrazione su chip del generatore fononico, dato l'incremento della sua stabilità e affidabilità. Inoltre, sono stati compiuti sforzi per indagare i) l'estrazione del coerente fononi generati, con particolare attenzione all'equilibrio tra l'avere la necessità di un elevato fattore Q (essenziale per consentire il comportamento auto-pompato) insieme con la necessità di generare una perdita di energia meccanica e ii) la progettazione di una guida d'onda a bassa perdita, in grado di trasportare le informazioni fononiche lungo il chip. La terza parte della tesi introduce il SAW come soluzione valida per la lavorazione del fonone. Inizialmente, l'integrazione tra un launcher SAW generico (generalmente effettuata di una combinazione di InterDigitated Transciever (IDT), un materiale piezoelettrico sottile e un Si-substrato) e la cavitá OM é investigata. Un nuovo design in cui i terminali elettrici, ovvero dove viene generato il SAW, sono stati curvati radialmente per facilitare, dal punto di vista geometrico, il focus dell'onda meccanica verso una determinata regione è discusso. Successivamente, il problema di come modellare tale IDT curvo é affrontato. Addizionalmente, al fine di garantire una corretta calibrazione del SAW-launcher, un metodo numerico cha passa dalla sia rappresentazione di tipo Scattering Matrix (SM) sia dell'approccio TRL è stato sviluppato.<br>Optomechanical (OM) micro-cavities are object of intense tudy, as a possible source of new functionalities, concepts, and opportunities beyond standard technology, with regard to microwave phonon propagation, generation, and processing at micro and nanoscale. In this framework, nonlinear OM interaction is being intensively investigated, with a view to advanced device modulation. The above kind of research is highly interdisciplinary, moving along the frontier of many fields, i.e. microwave Surface Acoustic Wave (SAW) filters, photonics, and electronics, and at the boundary between nanophysics and quantum optics. In particular, some recent achievements of OM ground state cooling promise coherent control of the quantum motion of mechanical resonators. A relevant example is provided by the recent coupling of a superconducting qubit to the mechanical vibrations of a piezoelectric resonator, i.e. microwave mechanical resonators operated at the quantum limit. Fundamental mechanisms of OM systems, such as the radiation pressure and the electrostrictive force exerted by electromagnetic fields on the matter, and, reversely, photoelastic modulation of electromagnetic fields, are responsible for strong interactions occurring in resonant cavities. In fact, huge pressures can act in the cavity region, owing to the high Q-factors achievable both for the optical and mechanical modes that coexist in the cavity. The above mechanism yields useful vibrational transduction and actuation at the µ- to m-watt power levels. Also it potentially leads to the development of phonon laser and detectors. Such development is likely to enable processing phonon signal at room temperature and integration of phononic elements on a silicon platform, capable of generating novel ways of information processing. The final objective is using phonons, instead of electrons, as vectors of information and building chips that work at room temperature, analogously to the operation of SAW-based devices, for filtering and sensing applications. Important advantages of this new technology are given, for example, by possible high frequency operation and low power consumption. In addition, comparing with pure nano-electromechanical actuation, the optical approach is less sensitive to capacitive and impedance mismatch issues. Given the above, the first part of this thesis deals with the theoretical interpretation of the OM phenomenon taking place in high-Q µ-cavities, having the aim of providing a reliable and rigorous approach for maximize the performances of a coherent phonon generator. If to consider the future development and progress of the OM circuitry, having a method capable of providing both the exact phononic population generated in a given cavity and the evaluation of the optical and mechanical forces that play their role in the interaction between the two physics, will be of fundamental importance. Together with the aforementioned numerical model, that has additionally been ported to a user-friendly application, original cavity designs exhibiting high degrees of confinement of both the optical and the mechanical resonating modes are given. The second part of this thesis focuses on the optical excitation of the coherent phonon generator, proposing a design made of a Si-slab that is first blended and then selectively etched, so that the evanescent tail of the E-field can be enhanced and, consequently, the EM energy transfer between such slab and the OM cavity can be maximized. This solution not only guarantees better performances in respect to the standard fiber-loop approach, but it is also suitable for an on-chip integration of the phononic generator, given its improved stability and reliability. Additionally, efforts are put in the investigation of i) the extraction of the coherent phonons generated in theOMcavity, with special focus on the balance between having the need of a high Q-factor (essential for enabling the self-pumped behavior) together with the necessity of generating some mechanical energy leak, and ii) the design of a low-loss waveguide, capable of carrying the phononic information along the chip. The third part of the thesis introduces the SAW as a valid solution for the phonon processing. At first, the integration between a generic SAW launcher (generally made of a combination of InterDigitated Transciever (IDT), a thin piezoelectric material and a Si-sustrate) and the targeted OM cavity is investigated. A novel design in which the electrical terminals, e.g. where the SAW is generated, have been radially curved for facilitating, from a geometrical point of view, the focus of the mechanical wave towards a certain region is given. Successively, the issue of modeling such curved IDT fingers is addressed. For ensuring a correct calibration of the SAW-launcher, aimed to isolate the latter from the rest of the OM circuitry, a numerical method making use of both the Scattering Matrix (SM) representation and the TRL approach is developed and tested against its analytic counterpart.

All of the writers who went to Spain during the Spanish Civil War had to cope with the differentness of Spain, with the fact that it was a foreign experience. How they handled that foreign experience, whether or not they found an entry point where they could cross the border between being an outsider to being an insider, why some writers were able to cross over and others halted: these are aspects of the outside/inside duality that this paper will bring to the surface in some of the writing of the period. The focus will be on the following women writers: Florence Farmborough, Helen Nicholson, Martha Gellhorn, Josephine Herbst, Frances Davis, Valentine Ackland and Sylvia Townsend Warner. This paper will argue that these women writers, although they came to Spain with different purposes â because they identified with Republican ideology, or to warn their home countries of the dangers of Red Spain, or to spur their home countries into action â shared a common struggle in attempting to become insiders to the war in Spain, and succeeded in varying and revealing degrees.<br>Master of Arts

A recent International Technology Roadmap for Semiconductors (ITRS) report (2.0, 2015 edition) has shown that Moore’s law is unlikely to hold beyond 2028. There is a need for alternate devices to replace CMOS based devices, if further miniaturization and high energy efficiency is desired. The goal of this dissertation is to experimentally demonstrate the feasibility of nanomagnetic memory and logic devices that can be clocked with acoustic waves in an extremely energy efficient manner. While clocking nanomagnetic logic by stressing the magnetostrictive layer of a multiferroic logic element with with an electric field applied across the piezoelectric layer is known to be an extremely energy-efficient clocking scheme, stressing every nanomagnet separately requires individual contacts to each one of them that would necessitate cumbersome lithography. On the other hand, if all nanomagnets are stressed simultaneously with a global voltage, it will eliminate the need for individual contacts, but such a global clock makes the architecture non-pipelined (the next input bit cannot be written till the previous bit has completely propagated through the chain) and therefore, unacceptably slow and error prone. Use of global acoustic wave, that has in-built granularity, would offer the best of both worlds. As the crest and the trough propagate in space with a velocity, nanomagnets that find themselves at a crest are stressed in tension while those in the trough are compressed. All other magnets are relaxed (no stress). Thus, all magnets are not stressed simultaneously but are clocked in a sequentially manner, even though the clocking agent is global. Finally, the acoustic wave energy is distributed over billions of nanomagnets it clocks, which results in an extremely small energy cost per bit per nanomagnet. In summary, acoustic clocking of nanomagnets can lead to extremely energy efficient nanomagnetic computing devices while also eliminating the need for complex lithography. The dissertation work focuses on the following two topics: Acoustic Waves, generated by IDTs fabricated on a piezoelectric lithium niobate substrate, can be utilized to manipulate the magnetization states in elliptical Co nanomagnets. The magnetization switches from its initial single-domain state to a vortex state after SAW stress cycles propagate through the nanomagnets. The vortex states are stable and the magnetization remains in this state until it is ‘reset’ by an external magnetic field. 2. Acoustic Waves can also be utilized to induce 1800 magnetization switching in dipole coupled elliptical Co nanomagnets. The magnetization switches from its initial single-domain ‘up’ state to a single-domain ‘down’ state after SAW tensile/compressive stress cycles propagate through the nanomagnets. The switched state is stable and non-volatile. These results show the effective implementation of a Boolean NOT gate. Ultimately, the advantage of this technology is that it could also perform higher order information processing (not discussed here) while consuming extremely low power. Finally, while we have demonstrated acoustically clocked nanomagnetic memory and logic schemes with Co nanomagnets, materials with higher magnetostriction (such as FeGa) may ultimately improve the switching reliability of such devices. With this in mind we prepared and studied FeGa films using a ferromagnetic resonance (FMR) technique to extract properties of importance to magnetization dynamics in such materials that could have higher magneto elastic coupling than either Co or Ni.

Im Rahmen dieser Arbeit wurde die Akustomigrationsresistenz von in Kupfertechnologie hergestellten SAW-Strukturen charakterisiert und diese mit dem Schädigungsverhalten von Al-basierten SAW-Strukturen unter gleichen Belastungsbedingungen verglichen. Dies wurde durch die Anwendung einer speziellen Power-SAW-Teststruktur ermöglicht. Das Schädigungsniveau wurde hierbei über die irreversible Verschiebung der Peakfrequenz bzw. durch Änderungen im elektrischen Widerstand sowie durch mikroskopische Untersuchung der Mikrostruktur beurteilt. Die durchgeführten SAW-Belastungsexperimente mit HF-Leistungen bis zu 4,5 W zeigten, dass das entwickelte Ta-Si-N/Cu/Ta-Si-N-System im Vergleich zur Al/Ti-Metallisierung eine Akustomigrationsresistenz besitzt, die um mehr als drei Größenordnungen höher ist als jene der Al/Ti-Metallisierung. Hohe SAW-Belastungen verursachten sowohl im Al- als auch im Cu-Testwandler Hügel- und Lochbildung. Während die Hügel in der Al/Ti-Metallisierung senkrecht zur Oberfläche bis zu einer Höhe von 1 µm und die Löcher bis hinab an die Ti-Schicht wuchsen, bildeten sich in den extrem belasteten Cu-basierten Wandlern nur flache Hügel und schmale Löcher aus, welche noch mit der Deckschicht vollständig bedeckt waren. Anhand von REM/EBSD, TEM sowie FIB-Untersuchungen konnte ein relevanter Zusammenhang zwischen der Mikrostruktur und dem Schädigungsverhalten aufgezeigt werden.

A detailed theoretical analysis is presented for calculating the surface acoustic wave (SAW) reflection coefficient of thin metallic layers. Based on this analysis, directions of propagation are classified as symmetric or asymmetric. An augmented scalar transmission line circuit model which contains a new lumped network element that accounts for asymmetry is introduced to describe SAW reflection and transmission through a strip. The resulting network model is used to analyze grating and transducer structures. Computed results based on this new network model are in excellent agreement with measured data, not only on devices oriented along symmetric directions, but also on devices which exhibit directivity due to asymmetric orientations. A simple procedure, based on physical arguments, is outlined for the identification of high directivity orientations. An algebraic construction is given which demonstrates that the coupling-of-modes (COM) modelling of gratings and transducers is derivable from the new network model. Approximate explicit analytical expressions, in terms of the network model, are given for the COM model parameters. The properties of pseudo-surface-waves are re-examined and a new high-velocity pseudo-surface acoustic wave (HVPSAW) is described. It is shown that this mode, not referenced in the SAW device literature, has a low attenuation along certain directions, and is thus very attractive for high-frequency low-loss SAW devices.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>101<br>In this thesis, 128o rotated Y-cut lithium niobate is used as piezoelectric substrate and aluminum film is used as metal electrodes in the SAW devices. The operating frequency of the SAW devices is designed in the range of 433MHz. To study the characteristics of reflectors in wireless SAW device, we design an one-port SAW device with three types of reflector, namely open circuit grating, short circuit grating, and IDT type. By using the network analyzer and the inverse discrete Fourier transform, the dynamic behavior of the SAW devices in time domain is presented. In conclusion, the open circuit grating type reflector gives the highest return loss in time domain and the IDT type is the lowest one. The longer aperture of IDT and reflector has the lager SNR (signal-to-noise ratio) of the return loss in time domain. To study the characteristics of impedance-loaded IDT, the IDT type reflector was loaded with a variable resistor, and its return loss was measured. The experiment results show that the more pairs of IDT electrodes give the higher sensitivity to the resistance change. Finally, we combined our SAW device with the NTC (negative coefficient of temperature) thermistor and photoresistor as impedance-loaded SAW sensors. Experimental results show that our designs have good sensitivity as temperature sensor and photo sensor with temperature compensation.

碩士<br>國立臺灣科技大學<br>機械工程系<br>92<br>Diamond has the highest acoustic propagation property, making it an ideal substrate for surface acoustic wave (SAW) device when coupled with piezoelectric materials. In the work, SAW devices based on ZnO/NCD/silicon layered structure are successfully performed. The device response is analyzed with frequency and time domain methods. The resonant frequencies of the devices agree with the results of numerical simulation for sound propagation in layered media. We conclude that NCD is a highly attractive substrate material for SAW devices, possessing the high sound velocity of diamond but requiring less manufacture processing. Furthermore, LiNbO3 singe crystal is well-known for its superior electromechanical coupling coefficient (K2) among a wide variety of piezoelectric materials, which promise significant improvement in SAW device performance. However, the studies with regard to the integration of NCD and LiNbO3 substrate have been scarcely reported. In this study, smooth NCD films have successfully been synthesized on LiNbO3 substrates. To avoid the mismatch of thermal expansion, a thin silicon layer of amorphous and poly silicon were deposited on the LiNbO3 substrate serving as a good adhesion layer at the NCD/LiNbO3 interface. It is found that the initial NCD nucleation density and the quality of the NCD films are substantially enhanced by applying a negative bias during NCD film deposition. We believe that the novel NCD/LiNbO3 architecture exhibits significant high K2 properties will be superior to traditional silicon base diamond SAW devices.

碩士<br>逢甲大學<br>材料與製造工程所<br>96<br>The merits of the design not the only factor but the stability of operation affect the performance of band saw machine. For fully automatic band saw machine, the restricted operations caused absolutely fault like saw blade broken easily and saw blade life cycle shortly. The band saw machine is then useless for production as machine tool even if the shape is nice. How to higher the life time and cutting function of saw blade applying in band saw machine become a very important topic. Nowadays, bi-metal saw blade is most popular tool for band saw machine. The blade material 50CrNiMoVA firstly joint with the cutting teeth material M42 using electron beam welding, and apply heat treatment to form the bi-metal saw blade. The saw blade was turn reputably from 0 to 90 degree to execute the cutting operation surrounding the driven and idler wheels with tighten tension. There are many factors like saw blade bear turn torque, tension, cutting forces …etc. result a complex stress system. Therefore, the durability of saw blade must be shorter as production machining without life time analysis compared with machine design specification. And, the main reasons of losing efficacy are saw blade broken and teeth wear or collapse. The mainly motivations of this research are both of reducing the breakage of saw blade and extending the tool life time. Most of turn angle condition parameters of different widths saw blade setting depend on the experience of designer. It will cost much time and a big budget to get some accuracy data from a mount of experiments record. The finite element analysis software package code ANSYS Workbench was used to deeply simulate the key parameters running on the band saw machine. The optimization of band saw cutting conditions to match band saw machine design especially to higher machining efficiency and longer tool life time are presented.

碩士<br>中華大學<br>電機工程學系碩士班<br>95<br>Entering the 21st century, electronic equipment embedded with wireless transceiver became the new trend, for examples, wireless sensor, RFID, mobile computer, video system, car electronic system. For future life, we need more sensors to build up the intelligent living environments and sense the physical parameters anytime or anywhere. The easy-setup wireless sensor will be the best choice for constructing such an environment and possess the inevitable market potential. In this project, we will cooperate with MEMs R&D Dept. of Delta research center to implement the wireless SAW sensor system. Passive SAW sensor has the valuable benefits of powerless, small size, low cost and long range operation.

碩士<br>國立成功大學<br>電機工程學系碩博士班<br>91<br>Using a personal computer with “Distributive Control and Monitoring System” data acquisition modules and a self-designed “100 MHz frequency counter interface” which can transform frequency into dc voltage﹐this paper successfully developed a 100MHz “SAW Sensor Data Acquisition System” which can either be applied in SAW sensors characteristic experiment which request 100Hz precision or be a output driver and monitoring system used for gas or liquid SAW sensors﹒Because of using “Distributive Control and Monitoring System data acquisition modules”﹐if the 100MHz “SAW Sensor Data Acquisition System” uses “Web Access” internet remote control and monitoring application software or control program developed by Microsoft Visual Basic﹐which has internet remote control function﹒Then we can apply SAW sensors for internet remote control﹒

碩士<br>國立清華大學<br>電子工程研究所<br>95<br>Abstract In this thesis, our object is the fabrication process of SAW device, we divided our work into three parts： First, we used the LP-MOCVD system to deposited aluminum and aluminum nitride thin films, and found out the optimum deposited condition. Secondly, we used μ-contact printing technique to transfer aminosilane on aluminum substrate. At last, we fabricated the transducer fingers by using RIE. First at all, we deposited aluminum thin films on Si and SiO2 substrate and aluminum nitride on SiO2 and sapphire substrate to understand substrate dependent of CVD aluminum and aluminum nitride thin films. The aluminum thin film was successfully deposited on SiO2 substrate with temperature 400~600℃、Ar flow 100~200sccm、reactive pressure 0.6~2torr. The aluminum nitride thin film was successfully deposited on sapphire substrate with temperature 850~950℃、NH3 : Ar =10 :1~30 :1、reactive pressure 0.6~4torr. Secondly, we transfer aminosilane wire width of 2μm on aluminum substrate with imprinting pressure 10~200psi、temperature100℃、imprinting time 1 min by μ-contact printing technique. The altitude of aminosilane was 190~260nm. At least, we fabricated the aluminum wire line of 1μm by metal-reactive ion etching system.

Today’s wireless devices, like our smartphones, are able to handle multiple standards and bands for different applications, such as Bluetooth, Wi-Fi and data-voice communications. However, the cost of a modern transceiver is becoming mainly dominated by the large number of off-chip passive components, like Duplexers and SAW filters, needed to distinguish the desired signal among many interferences. Addressing the challenges that arise from the lack of RF filtering, a SAW-less architecture represents an interesting solution to reduce the platform complexity. This thesis proposes a feasible solution based on a SAW-less RF front-end able to meet the standard requirements and a digital system tailored to the RF path. The digital architecture, which represents the main topic of this thesis, is described in detail and experimentally tested to validate the proposed solutions.

La saga Saw est une franchise qui a marqué le cinéma d’horreur des années 2000. Le présent mémoire tâchera d’en faire une étude détaillée et rigoureuse en utilisant la notion de jeu. En élaborant tout d’abord un survol du cinéma d’horreur contemporain et en observant la réception critique de la saga à travers l’étude de différents articles, ce travail tentera en majeure partie d’analyser la franchise Saw en rapport avec l’approche ludique du cinéma en général et celle adoptée par Bernard Perron. Cette étude, qui s’élaborera tant au niveau diégétique que spectatoriel, aura pour but de montrer l’importance de la place qu’occupe la notion de jeu dans cette série de films.<br>The Saw saga is a franchise that marked the horror film industry in the 2000’s. This report will try and give a thorough and detailled study while using the idea of a game. At the same time taking a cursory glance at contemporary horror films and observing how the critics were received by studying different articles. This assignment will in majority analyse the Saw saga using a recreational approach of movies in general as well as the one adopted by Bernard Perron. This study will be elaborated on a "diegetique" and "spectatoriel" level – the goal being to show the importance that games occupy in this film series.