Dissertations / Theses: 'Signal devices'

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Davison, Alan Stephen. "All-optical signal processing devices." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316729.

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Taji, Bahareh. "Signal Quality Assessment in Wearable ECG Devices." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/38851.

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There is a current trend towards the use of wearable biomedical devices for the purpose of recording various biosignals, such as electrocardiograms (ECG). Wearable devices have different issues and challenges compared to nonwearable ones, including motion artifacts and contact characteristics related to body-conforming materials. Due to this susceptibility to noise and artifacts, signals acquired from wearable devices may lead to incorrect interpretations, including false alarms and misdiagnoses. This research addresses two challenges of wearable devices. First, it investigates the effect of applied pressure on biopotential electrodes that are in contact with the skin. The pressure affects skin–electrode impedance, which impacts the quality of the acquired signal. We propose a setup for measuring skin–electrode impedance during a sequence of applied calibrated pressures. The Cole–Cole impedance model is utilized to model the skin–electrode interface. Model parameters are extracted and compared in each state of measurement with respect to the amount of pressure applied. The results indicate that there is a large change in the magnitude of skin–electrode impedance when the pressure is applied for the first time, and slight changes in impedance are observed with successive application and release of pressure. Second, this research assesses the quality of ECG signals to reduce issues related to poor-quality signals, such as false alarms. We design an algorithm based on Deep Belief Networks (DBN) to distinguish clean from contaminated ECGs and validate it by applying real clean ECG signals taken from the MIT-BIH arrhythmia database of Physionet and contaminated signals with motion artifacts at varying signal-to-noise ratios (SNR). The results demonstrate that the algorithm can recognize clean from contaminated signals with an accuracy of 99.5% for signals with an SNR of -10 dB. Once low- and high-quality signals are separated, low-quality signals can undergo additional pre-processing to mitigate the contaminants, or they can simply be discarded. This approach is applied to reduce the false alarms caused by poor-quality ECG signals in atrial fibrillation (AFib) detection algorithms. We propose a signal quality gating system based on DBN and validate it with AFib signals taken from the MIT-BIH Atrial Fibrillation database of Physionet. Without gating, the AFib detection accuracy was 87% for clean ECGs, but it markedly decreased as the SNR decreased, with an accuracy of 58.7% at an SNR of -20 dB. With signal quality gating, the accuracy remained high for clean ECGs (87%) and increased for low SNR signals (81% for an SNR of -20 dB). Furthermore, since the desired level of quality is application dependent, we design a DBN-based algorithm to quantify the quality of ECG signals. Real ECG signals with various types of arrhythmias, contaminated with motion artifacts at several SNR levels, are thereby classified based on their SNRs. The results show that our algorithm can perform a multi-class classification with an accuracy of 99.4% for signals with an SNR of -20 dB and an accuracy of 91.2% for signals with an SNR of 10 dB.

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McGhee, Joseph. "Models, measures and signals : collected works in modelling, measurement science and technology and signal engineering." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248818.

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Atabaki, Amir Hossein. "Reconfigurable silicon photonic devices for optical signal processing." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41207.

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Processing of high-speed data using optical signals is a promising approach for tackling the bandwidth and speed challenges of today's electronics. Realization of complex optical signal processing functionalities seems more possible than any time before, thanks to the recent achievements in silicon photonics towards large-scale photonic integration. In this Ph.D. work, a novel thermal reconfiguration technology is proposed and experimentally demonstrated for silicon photonics that is compact, low-loss, low-power, fast, with a large tuning-range. These properties are all required for large-scale optical signal processing and had not been simultaneously achieved in a single device technology prior to this work. This device technology is applied to a new class of resonator-based devices for reconfigurable nonlinear optical signal processing. For the first time, we have demonstrated the possibility of resonance wavelength tuning of individual resonances and their coupling coefficients. Using this new device concept, we have demonstrated tunable wavelength-conversion through four-wave mixing in a resonator-based silicon device for the first time.

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Liu, Haibo. "SEED devices used in optical signal processing applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq25657.pdf.

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Penty, Richard Vincent. "Novel optical fibre Kerr devices for signal processing." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291606.

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McDougall, Robert Campbell. "Hybrid integration for all-optical signal processing devices." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614278.

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Drummond, Miguel Vidal. "Photonic devices for optical and RF signal processing." Doctoral thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7562.

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Doutoramento em Engenharia Electrotécnica
O presente trabalho tem por objectivo o estudo de novos dispositivos fotónicos aplicados a sistemas de comunicações por fibra óptica e a sistemas de processamento de sinais RF. Os dispositivos apresentados baseiam-se em processamento de sinal linear e não linear. Dispositivos lineares ópticos tais como o interferómetro de Mach-Zehnder permitem adicionar sinais ópticos com pesos fixos ou sintonizáveis. Desta forma, este dispositivo pode ser usado respectivamente como um filtro óptico em amplitude com duas saídas complementares, ou, como um filtro óptico de resposta de fase sintonizável. O primeiro princípio de operação serve como base para um novo sistema fotónico de medição em tempo real da frequência de um sinal RF. O segundo princípio de operação é explorado num novo sistema fotónico de direccionamento do campo eléctrico radiado por um agregado de antenas, e também num novo compensador sintonizável de dispersão cromática. O processamento de sinal é não linear quando sinais ópticos são atrasados e posteriormente misturados entre si, em vez de serem linearmente adicionados. Este princípio de operação está por detrás da mistura de um sinal eléctrico com um sinal óptico, que por sua vez é a base de um novo sistema fotónico de medição em tempo real da frequência de um sinal RF. A mistura de sinais ópticos em meios não lineares permite uma operação eficiente numa grande largura espectral. Tal operação é usada para realizar conversão de comprimento de onda sintonizável. Um sinal óptico com multiplexagem no domínio temporal de elevada largura de banda é misturado com duas bombas ópticas não moduladas com base em processos não lineares paramétricos num guia de ondas de niobato de lítio com inversão periódica da polarização dos domínios ferroeléctricos. Noutro trabalho, uma bomba pulsada em que cada pulso tem um comprimento de onda sintonizável serve como base a um novo conversor de sinal óptico com multiplexagem no domínio temporal para um sinal óptico com multiplexagem no comprimento de onda. A bomba é misturada com o sinal óptico de entrada através de um processo não linear paramétrico numa fibra óptica com parâmetro não linear elevado. Todos os dispositivos fotónicos de processamento de sinal linear ou não linear propostos são experimentalmente validados. São também modelados teoricamente ou através de simulação, com a excepção dos que envolvem mistura de sinais ópticos. Uma análise qualitativa é suficiente nestes últimos dispositivos.
This work investigates novel photonic devices for optical fiber communication systems and microwave photonics. Such devices rely on linear and nonlinear optical signal processing. Basic linear optical devices such as the Mach-Zehnder delay interferometer enable delaying and adding optical signals with fixed or variable weights. Therefore, such device can be respectively used as an optical amplitude filter with two complementary optical outputs, or, as an optical phase filter with tunable group delay response. The first operation principle is explored in a novel instantaneous RF frequency measurement system, whereas the latter serves as basis to a novel photonic beamforming system for a phase array antenna, and also to a novel tunable optical dispersion compensator. Nonlinear optical signal processing is obtained when optical signals are delayed and mixed, instead of being linearly added. Such operation principle is behind electro-optical mixing, which is explored in a novel instantaneous RF frequency measurement system. All-optical mixing enables ultra-fast and thereby broad bandwidth operation. This operation principle is explored to obtain tunable wavelength conversion. An optical time division multiplexed signal with a large spectral width is parametrically mixed with two continuous wave pumps in a periodically-poled lithium niobate waveguide. Instead of continuous wave pumps, a pulsed pump in which each pulse has a tunable wavelength enables a novel routable optical time-to-wavelength division converter. The pump signal is parametrically mixed with the input optical signal in a highly nonlinear optical fiber. All the proposed linear and nonlinear optical signal processing devices are experimentally validated. In addition, theoretical modeling and simulations are presented in all concepts, with the exception of the ones which employ alloptical mixing. A qualitative analysis is sufficient for the latter devices.

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Amprikidis, Michael. "Vibration sensing using piezoelectric devices and signal conditioning." Thesis, University of Manchester, 2004. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488086.

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Howell, Mark John. "Signal processing for X ray spectroscopy." Thesis, Bangor University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361173.

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Ehteshami, Nasrin. "Silicon Photonic Devices for Microwave Signal Generation and Processing." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34111.

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Silicon photonics as a one of the most promising photonic integration technologies has attracted many attentions in recent years. The major feature of this technology is its compatibility with complementary metal-oxide semiconductor (CMOS) processes which makes it possible to integrate optical and electronic devices in a same chip and reduce the cost significantly. Another reason of using silicon photonics is the high index contrast between the silicon core and silicon dioxide cladding which ensures the high density integration of photonic devices on a single chip. Monolithic integration with electronic and optical circuits makes silicon photonics technology suitable for numerous applications. One example is microwave photonics (MWP). MWP is an area that studies the interaction between microwave and optical signal for the generation, processing, control and distribution of microwave signals by means of photonics. Silicon photonics offers a reduction in footprint, losses, packaging cost and power dissipation in MWP systems. This research in this thesis is focused on the design and fabrication of the silicon photonic devices for MWP signal processing and generation. Four MWP systems based on silicon photonic devices are proposed and experimentally demonstrated. 1) A single pass-band frequency-tunable MWP filter based on phase-modulation to intensity-modulation conversion in an optically pumped silicon-on-insulator (SOI) microring resonator (MRR) is designed and experimentally demonstrated. In the proposed filter, a phase-modulated optical signal is filtered by the SOI MRR, to have one first-order sideband suppressed by the MRR notch. The phase-modulated optical signal is converted to an intensity-modulated single-sideband (SSB) signal and detected at a photodetector (PD). The entire operation is equivalent to a single pass-band filter. The frequency tunability is achieved by tuning the resonance wavelength of the MRR, which is realized by optically pumping the MRR. A single pass-band MWP filter with a tunable center frequency from 16 to 23 GHz is experimentally demonstrated. 2) A broadband optically tunable MWP phase shifter with a tunable phase shift using three cascaded SOI MRRs that are optically pumped is designed and experimentally demonstrated. A microwave signal to be phase shifted is applied to an optical single-sideband (OSSB) modulator to generate an optical carrier and an optical sideband. The phase shift is introduced to the optical carrier by placing the optical carrier within the bandwidth of one resonance of the three cascaded MRRs. The experimental results show that by optically pumping the cascaded MRRs, a broadband MWP phase shifter with a bandwidth of 7 GHz with a tunable phase shift covering the entire 360o phase shift range is achieved. 3) A multi tap MWP filter with positive and negative coefficients using a silicon ring resonator modulator (RRM) is proposed and experimentally demonstrated. The RRM is designed and fabricated to operate based on the carrier depletion effect. The positive and negative coefficients are obtained by using opposite slopes of the modulation transmission response of the RRM. Two filter responses with two and three taps are experimentally demonstrated, showing the proof-of-principle for frequencies up to 18 GHz. 4) An approach to generate microwave signal based on enhanced four wave mixing (FWM) in an active silicon waveguide (SiWG) is studied. This SiWG is designed and fabricated, and the use of the active SiWG for MWP frequency multiplication to generate a frequency-sextupled millimeter-wave signal is experimentally demonstrated. Thanks to a reverse-biased p-n junction across the SiWG, the conversion efficiency of the FWM is improved, which leads to the improvement of the microwave frequency multiplication efficiency.

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Koos, Christian. "Nanophotonic devices for linear and nonlinear optical signal processing." Karlsruhe : Univ.-Verl. Karlsruhe, 2007. http://d-nb.info/987044451/34.

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Jin, M. "SOI technology for MOS devices and mixed signal applications." Thesis, Queen's University Belfast, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437426.

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Halimic, Mirsad Kjazim. "Performance improvement of dynamic weighing systems using optimal control and advanced signal processing methods." Thesis, Brunel University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249791.

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Chen, Jianxiao. "Tunable electro-optic devices for fiber optical RF signal processing." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3203495.

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Thesis (Ph. D.)--University of California, San Diego, 2006.
Title from first page of PDF file (viewed March 1, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

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Yoon, Kwang Sub. "A precision analog small-signal model for submicron MOSFET devices." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/14935.

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Corbari, Costantino. "Development of non-linear waveguide devices for optical signal processing." Thesis, University of Southampton, 2005. https://eprints.soton.ac.uk/65506/.

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Reported in this thesis are advances in glass poling, a technique which produces second-order optical nonlinearity in glass. Poling of glass has drawn much attention because frequency conversion and electro-optic modulation, operations which are typically restricted to crystals, becomes feasible in glass fibres and waveguides which are widely spread media in photonics thanks to their excellent optical properties and mature manufacturing technology. Poled silica glass, despite showing about 10 times lower second-order nonlinearity than nonlinear crystals, can be competitive with them because longer interaction lengths are possible in glass fibres, owing to the lower chromatic dispersion. -gratings in fibres. This technology led to the first demonstration of an all-fibre frequency doubler of a fibre laser. Milliwatts of red light in the fundamental mode were produced by frequency doubling in a quasi-phase matched periodically poled silica fibre which was directly spliced to the output of the laser source. Efficiency up to 2.5% has been demonstrated in 11.5 cm long device with only about 100W of pump power, which means that 50% conversion efficiency is expected for a 2kW input power.

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Schneider, Bradley A. "Gait Analysis from Wearable Devices using Image and Signal Processing." Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1514820042511803.

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Huang, Jie. "Multifunctional optical signal-processing devices in periodically poled lithium niobate /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.

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Kim, Sangtaek. "Acousto-optic devices for optical signal processing and quantum computing." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3303851.

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Clausen, William. "Small and large signal modeling of MM-Wave MHEMT devices." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000177.

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Pinto, Domenico. "Numerical modelling of photonic crystals devices for all-optical signal processing." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511143.

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Call, John B. "Large-signal characterization and modeling of nonlinear devices using scattering parameters." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35548.

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Characterization and modeling of devices at high drive levels often requires specialized equipment and measurement techniques. Many large-signal devices will never have traditional nonlinear models because model development is expensive and time-consuming. Due to the complexity of the device or the size of the application market, nonlinear modeling efforts may not be cost effective. Scattering parameters, widely used for small-signal passive and active device characterization, have received only cursory consideration for large-signal nonlinear device characterization due to technical and theoretical issues. We review the theory of S-parameters, active device characterization, and previous efforts to use S-parameters with large-signal nonlinear devices. A robust, calibrated vector-measurement system is used to obtain device scattering parameters as a function of drive level. The unique measurement system architecture allows meaningful scattering parameter measurements of large-signal nonlinear devices, overcoming limitations reported by previous researchers. A three-port S-parameter device model, with a nonlinear reflection coefficient terminating the third port, can be extracted from scattering parameters measured as a function of drive level. This three-port model provides excellent agreement with device measurements across a wide range of drive conditions. The model is used to simulate load-pull data for various drive levels which are compared to measured data.
Master of Science

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Teixeira, Hugo Miguel dos Santos. "Nonlinear behavioral modeling of mixed signal RF-digital I/O devices." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12048.

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Doutoramento em Engenharia Electrotécnica
Esta tese investiga a caracterização (e modelação) de dispositivos que realizam o interface entre os domínios digital e analógico, tal como os buffers de saída dos circuitos integrados (CI). Os terminais sem fios da atualidade estão a ser desenvolvidos tendo em vista o conceito de rádio-definido-por-software introduzido por Mitola. Idealmente esta arquitetura tira partido de poderosos processadores e estende a operação dos blocos digitais o mais próximo possível da antena. Neste sentido, não é de estranhar que haja uma crescente preocupação, no seio da comunidade científica, relativamente à caracterização dos blocos que fazem o interface entre os domínios analógico e digital, sendo os conversores digital-analógico e analógico-digital dois bons exemplos destes circuitos. Dentro dos circuitos digitais de alta velocidade, tais como as memórias Flash, um papel semelhante é desempenhado pelos buffers de saída. Estes realizam o interface entre o domínio digital (núcleo lógico) e o domínio analógico (encapsulamento dos CI e parasitas associados às linhas de transmissão), determinando a integridade do sinal transmitido. Por forma a acelerar a análise de integridade do sinal, aquando do projeto de um CI, é fundamental ter modelos que são simultaneamente eficientes (em termos computacionais) e precisos. Tipicamente a extração/validação dos modelos para buffers de saída é feita usando dados obtidos da simulação de um modelo detalhado (ao nível do transístor) ou a partir de resultados experimentais. A última abordagem não envolve problemas de propriedade intelectual; contudo é raramente mencionada na literatura referente à caracterização de buffers de saída. Neste sentido, esta tese de Doutoramento foca-se no desenvolvimento de uma nova configuração de medição para a caracterização e modelação de buffers de saída de alta velocidade, com a natural extensão aos dispositivos amplificadores comutados RF-CMOS. Tendo por base um procedimento experimental bem definido, um modelo estado-da-arte é extraído e validado. A configuração de medição desenvolvida aborda não apenas a integridade dos sinais de saída mas também do barramento de alimentação. Por forma a determinar a sensibilidade das quantias estimadas (tensão e corrente) aos erros presentes nas diversas variáveis associadas ao procedimento experimental, uma análise de incerteza é também apresentada.
This thesis investigates the characterization (and modeling) of devices that perform the interface between the digital and analog domains, such as the output buffers of the Integrated Circuits (ICs). Modern wireless transceivers are moving towards the software-defined radio (SDR) concept proposed by Mitola. The ideal architecture makes use of powerful digital signal processors (DSP) and extends the digital blocks’s operation as close as possible to the antenna. In this way, it is not surprising that there is a growing concern regarding the characterization of the blocks that perform the interface between the analog and digital domains, being the analog-to-digital and digital-to-analog converters (ADCs/DACs) two good examples of these circuits. Within the high speed digital circuits, such as Flash memories, a similar role is played by the output buffers. They act as an interface between the digital (logic core) and the analog radio frequency domains (package/printed circuit board), determining the signal integrity of the transmitted data. In order to speed up the signal integrity analysis, at the design stage, it is fundamental to have models that are simultaneously computationally efficient and accurate. Typically, the extraction/validation of models for output buffers is performed by using characterization data obtained from either the simulation of the transistor level model (if available) or from measurements. The latter approach is not sensitive to intellectual property issues but is rarely addressed in literature referred to output buffers’ characterization. Therefore, this thesis addresses the development of a novel measurement setup for the characterization and modeling of high speed output buffers, naturally extendable to switched-mode RF-CMOS amplifiers. Based on a welldefined experimental procedure, a state of the art model is extracted and validated. The developed measurement setup addresses not only the integrity of the output signals (signal integrity) but also of the power supply voltages (power integrity). In order to determine the sensitivity of the estimated quantities (voltage and current) to the errors in the different variables of the experimental procedure, an uncertainty analysis is presented.

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Brosi, Jan-Michael. "Slow-light photonic crystal devices for high-speed optical signal processing." Karlsruhe : Universitätsverlag, 2009. http://digbib.ubka.uni-karlsruhe.de/volltexte/1000009905.

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Brosi, Jan-Michael. "Slow light photonic crystal devices for high speed optical signal processing." Karlsruhe Univ.-Verl. Karlsruhe, 2008. http://d-nb.info/992585090/04.

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Senthinathan, Ramesh 1961. "Signal integrity and simultaneous switching noise of CMOS devices and systems." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/565539.

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Kale, Kaustubh R. "Low complexity, narrow baseline beamformer for hand-held devices." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001223.

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Cordero, Álvarez Rafael. "Subcutaneous Monitoring of Cardiac Activity for Chronically Implanted Medical Devices." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS020.

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L'objectif de cette thèse de doctorat est le développement de capteurs et d'algorithmes pour une meilleure surveillance de l'activité cardiaque dans un défibrillateur cardioverteur implantable sous-cutané (S-ICD), et plus précisément pour améliorer la spécificité de détection des tachyarythmies dangereuses telles que la tachycardie ventriculaire (TV) et la fibrillation ventriculaire (FV) dans le S-ICD. Deux schémas de détection TV/FV indépendants ont été développés dans ce but : l'un de nature électrophysiologique et l'autre hémodynamique. Le schéma de détection électrophysiologique repose sur un ECG spécial qui a été enregistré le long d'un dipôle «court» situé au-dessus du grand pectoral inférieur gauche. Ce dipôle court maximise le rapport R/T et le rapport signal/bruit chez 9 volontaires sains. En théorie, cela devrait réduire le risque de détections faussement positives de TV/ FV simplement en raison de la taille, de l'emplacement et de l'orientation du dipôle, indépendamment de toute autre méthode de traitement du signal. Le schéma de détection hémodynamique repose quant à lui sur les vibrations cardiaques enregistrées par deux prototypes de capteurs accéléromètres triaxiaux. Les vibrations cardiaques sous-cutanées mesurées ont été caractérisées, validées physiologiquement et optimisées via leur filtrage le long de bandes passantes spécifiques et leur projection le long d'un référentiel spécifique patient. Le premier algorithme au monde indépendant de détection de FV par vibration cardiaque a été développé en opérant sur ces signaux optimisés. Les mêmes prototypes d'accéléromètre se sont également avérés capables d'enregistrer des accélérations respiratoires et de détecter l'apnée. Enfin, un dernier prototype de sonde sous-cutanée composite, composé de trois électrodes, d'un accéléromètre bi-axial et de connecteurs d'appareil standard. Ce prototype est capable d'enregistrer l'ECG dipolaire court, les vibrations cardiaques et les accélérations respiratoires. Cette sonde prototype a été implantée dans un quatrième et dernier animal
The aim of this doctoral thesis was the development of sensors and algorithms for the improved monitoring of cardiac activity in the subcutaneous implantable cardioverter-defibrillator (SICD). More precisely, to improve the detection specificity of dangerous tachyarrhythmia such as ventricular tachycardia (VT) and ventricular fibrillation (VF). Two independent VT/VF detection schemes were developed for this: one electrophysiological in nature, and the other hemodynamic. The electrophysiological sensing scheme relied on a special ECG that was recorded along a short dipole located above the lower left pectoralis major. This short dipole maximised R/T ratio and signal-to-noise ratio in a total of 9 healthy volunteers. In theory, it will reduce the risk of false positive VT/VF detections simply by consequence of the dipole size, location, and orientation and independently of any further signal processing methods. The hemodynamic sensing scheme relied on cardiac vibrations recorded from two tri-axial accelerometer prototype sensors. These subcutaneous cardiac vibrations were characterised, physiologically validated, and optimised via their filtering along specific bandwidths and projection along a patient specific reference frame. The world’s first independent cardiac vibration VF detection algorithm was developed operating on these optimised signals. The same accelerometer prototypes were also shown to be able to record respiratory accelerations and detect apnoea. A final subcutaneous lead prototype was developed capable of recording the short dipole ECG, cardiac vibrations, and respiratory accelerations. It consisted of three electrodes, a bi-axial accelerometer, and industry-standard device connectors. The prototype lead was implanted in a fourth and final animal

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Koos, Christian [Verfasser]. "Nanophotonic devices for linear and nonlinear optical signal processing / von Christian Koos." Karlsruhe : Univ.-Verl. Karlsruhe, 2007. http://d-nb.info/987044451/34.

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Venkatesha, Divya. "Small signal characterisation of microwave active and passive devices using eye diagrams." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625128.

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This thesis presents new results for the use of eye diagrams as a functional tool to study the response of components, which may be a simple transistor, an amplifier or even the entire transreceiver system, particularly in the digital environment. Conventionally, S-parameter methods are used to evaluate the performance of devices at high frequencies but these do not offer complete performance characteristics, especially when the components are used in digital applications. In this project it is shown that the eye diagram can be effectively employed to provide an additional measurement tool to quantify the performance of active and passive components. The eye diagram, which have always been used as a mere visual tool in the past, has been shown in this work to be a very powerful tool, which helps in the optimization of components, especially for use in optical applications. In this work, eye diagrams have been generated, measured and also simulated for different passive components, i.e., transmission lines and active components i.e., InGaP/GaAs HBTs and GaAs pHEMTs. It is shown that various eye parameters relate directly to the physics of the components under test. Sensitivity analysis has also been carried out to study the switching characteristics of components using the eye diagrams. Using both experimental and simulation data, in this work it is shown that the eye diagram parameters can be studied to provide feedback to further optimize the components under test. Various parameters of both active and passive components have been measured and evaluated providing a comprehensive study of their behaviours and the way forward to optimize the structure of components for generating improved eye characteristics for digital applications. The measured results are also validated by simulations using Agilent's Advanced Design System. Small signal parameters of both HBTs and pHEMTs have been extracted using direct extraction method through IC-CAP and these were used in the simulation of eye diagrams. The procedures developed in this study would assist in the implementation of techniques to improve microwave component performance based on the feedback from the eye diagram analyses and to develop methodologies to build systems based on the eye diagram specifications.

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32

Pashine, Rajat. "Signal analysis for multiple target materials through wavelet transforms." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2010. http://scholarsmine.mst.edu/thesis/pdf/Pashine_09007dcc8074b5e0.pdf.

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Thesis (M.S.)--Missouri University of Science and Technology, 2010.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 8, 2010) Includes bibliographical references (p. 46-47).

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Thomson, Kyle E. "Hardware considerations of space-time processing in implantable neuroprosthetic devices." Diss., Connect to online resource - MSU authorized users, 2006.

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Thesis (M.S.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2006.
Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 51-52). Also issued in print.

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34

Lauermann, Matthias [Verfasser]. "Silicon-organic hybrid devices for high-speed electro-optic signal processing / Matthias Lauermann." Karlsruhe : KIT Scientific Publishing, 2018. http://www.ksp.kit.edu.

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35

Зубков, О. В., І. В. Свид, О. С. Мальцев, and Л. Ф. Сайківська. "In-circuit Signal Analysis in the Development of Digital Devices in Vivado 2018." Thesis, Theoretical and Applied Aspects of Device Development on Microcontrollers and FPGAs, MC&FPGA-2019, 2019. https://doi.org/10.35598/mcfpga.2019.003.

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Considered the implementation of in-circuit analysis of logical signals in digital devices synthesized in Xilinx Field-Programmable Gate Array. Designed a digital control device streaming analog-to-digital converter. An analysis of the results of the analog-digital conversion was carried out and measures were taken to smooth out the false results of the conversion.

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Зубков, О. В., І. В. Свид, О. С. Мальцев, and Л. Ф. Сайківська. "In-circuit Signal Analysis in the Development of Digital Devices in Vivado 2018." Thesis, NURE, MC&FPGA, 2019. https://mcfpga.nure.ua/conf/2019-mcfpga/10-35598-mcfpga-2019-003.

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Considered the implementation of in-circuit analysis of logical signals in digital devices synthesized in Xilinx Field-Programmable Gate Array. Designed a digital control device streaming analog-to-digital converter. An analysis of the results of the analog-digital conversion was carried out and measures were taken to smooth out the false results of the conversion.

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37

Harter, Tobias [Verfasser], and C. [Akademischer Betreuer] Koos. "Wireless Terahertz Communications: Optoelectronic Devices and Signal Processing / Tobias Harter ; Betreuer: C. Koos." Karlsruhe : KIT Scientific Publishing, 2021. http://d-nb.info/1235140962/34.

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38

Harter, Tobias [Verfasser], and C. [Akademischer Betreuer] Koos. "Wireless Terahertz Communications: Optoelectronic Devices and Signal Processing / Tobias Harter ; Betreuer: C. Koos." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/1219577936/34.

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39

Paulsen, Ronald Ray 1951. "DESIGN AND BUILD OF A STORAGE SYSTEM FOR STRESS TESTING (WORD GENERATOR, SIGNAL SOURCE)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/291237.

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Schlottmann, Craig Richard. "Analog signal processing on a reconfigurable platform." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29623.

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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Hasler, Paul; Committee Member: Anderson, David; Committee Member: Ghovanloo, Maysam. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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41

Birr, Tobias [Verfasser]. "Investigation of plasmonic structures for use as sensors and signal processing devices / Tobias Birr." Hannover : Technische Informationsbibliothek (TIB), 2017. http://d-nb.info/1153076330/34.

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42

Cardoso, Adilson Silva. "Design and characterization of BiCMOS mixed-signal circuits and devices for extreme environment applications." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53099.

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State-of-the-art SiGe BiCMOS technologies leverage the maturity of deep-submicron silicon CMOS processing with bandgap-engineered SiGe HBTs in a single platform that is suitable for a wide variety of high performance and highly-integrated applications (e.g., system-on-chip (SOC), system-in-package (SiP)). Due to their bandgap-engineered base, SiGe HBTs are also naturally suited for cryogenic electronics and have the potential to replace the costly de facto technologies of choice (e.g., Gallium-Arsenide (GaAs) and Indium-Phosphide (InP)) in many cryogenic applications such as radio astronomy. This work investigates the response of mixed-signal circuits (both RF and analog circuits) when operating in extreme environments, in particular, at cryogenic temperatures and in radiation-rich environments. The ultimate goal of this work is to attempt to fill the existing gap in knowledge on the cryogenic and radiation response (both single event transients (SETs) and total ionization dose (TID)) of specific RF and analog circuit blocks (i.e., RF switches and voltage references). The design approach for different RF switch topologies and voltage references circuits are presented. Standalone Field Effect Transistors (FET) and SiGe HBTs test structures were also characterized and the results are provided to aid in the analysis and understanding of the underlying mechanisms that impact the circuits' response. Radiation mitigation strategies to counterbalance the damaging effects are investigated. A comprehensive study on the impact of cryogenic temperatures on the RF linearity of SiGe HBTs fabricated in a new 4th-generation, 90 nm SiGe BiCMOS technology is also presented.

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Lentine, Anthony L. "Issues in the design of self electro-optic effect devices for optical signal processing." Thesis, Heriot-Watt University, 1993. http://hdl.handle.net/10399/1474.

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Lee, Ju Han. "All-optical nonlinear signal processing devices and their applications within fibre-optic communication systems." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/42436/.

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This thesis is concerned with research into the development of a range of all-optical fibre based nonlinear devices for optical communication applications. The research can he divided into two main themes. The first concerns the use nf superstructured fibre Bragg grating technology together with fibre based nonlinear devices to improve the overall system performance in both OCDMA and OTDM systems. The second theme area concerns the use of highly nonlinear holey fibre within a range of nonlinear signal processing devices and an analysis of the perfomance of these devices from a system context. A range of nonlinear devices based on a holey fibre is demonstrated. Holey fibre has a nonlinearity around 10-100 times greater than conventional fibre. The use of a short (8.7 m), highly nonlinear holey fibre based optical switch is presented and shown to provide enhanced code recognition quality in a SSFBG based OCDMA system. The use of a short (75 m), highly nonlinear holey fibre to obtain strong L+-band Raman amplification and SRS based signal modulation is also demonstrated. The use of HF within Brillouin based devices is next considered. Both stimulated and spontaneous Brillouin scattering effects are investigated. The observed high SBS lasing threshold is found to be mainly due to reduction in the effective gain coefficient caused by structural non-uniformity along the HF length. A 5.8 m length of HF is then used to achieve tuneable WDM wavelength conversion based on XPM and it is experimentally demonstrated that HF with normal GVD should be used for this sort of device in order to eliminate the coherence degradation related intensity noise observed in experiments employing anomalously dispersive HF. Finally, a FWM based wavelength converter using a 15 m, highly nonlinear HF with a high SBS threshold is presented. The high SBS threshold is achieved by applying structural variation to the HF along its length during the fabrication process

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45

Clausen, William 1972. "Small and large signal modeling of MM-Wave MHEMT devices [electronic resource] / by William Clausen." University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000177.

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Title from PDF of title page.
Document formatted into pages; contains 155 pages.
Thesis (M.S.E.E.)--University of South Florida, 2003.
Includes bibliographical references.
Text (Electronic thesis) in PDF format.
ABSTRACT This research effort advances millimeter-wave transistor modeling in a current RF/Microwave circuit simulator (Agilent's Advanced Design System-ADS) for small-signal noise and large signal simulations. The device modeled is a metamorphic High Electron Mobility Transistor (mHEMT) supplied by Raytheon RF components. Because of their structure, these new low noise devices are used in this work to test the abilities to accurately model in the sub 0.5dB noise figure territory and to study model prediction into W-band (75-110 GHz). New modeling issues discussed in this thesis involve the effects of noise modeling in relation to the small-signal model parameters. The noise modeling identifies two methods of extraction and how to determine good noise data.
ABSTRACT: Other modeling topics addressed are the use of an advanced nonlinear model, and the ability to optimize for gain compression in the nonlinear model. Several measurement systems were used in the extraction and validation of this modeling effort. They consist of the ATN NP5 noise system, Maury Automated Tuner System, Agilent's IC-CAP, and Gateway's Special. The concept behind using these systems was to construct a complete modeling reference for a transistor and validate it against noise parameter and nonlinear measured data. Since the modeling work for this thesis is built on previous work, one goal has been to bring past USF field-effect transistor (FET) modeling efforts up to date and refine them for future use. The noise measurements were compared to results from Raytheon to validate the USF ATN noise parameter measurement system. Also the IC-CAP modeling system has been validated in measuring the test devices using the Maury load-pull system.
ABSTRACT: Small-signal and noise modeling were accomplished using techniques standardized from several technical papers and prior USF Ph.D. work relative to the model extraction. The IC-CAP modeling software also provided a straightforward platform for large-signal model extraction that is documented in this thesis. Using optimization in ADS, a final nonlinear was created. Measured DC, S-parameter, noise parameters, harmonic power, TOI, load-pull, and efficiency measurements were shown to compare well with model data simulated in ADS. Temperature scaling was also executed using a linear approximation of model values over measured temperatures in the noise model. The results presented show that the models developed illustrate good fitting of the behavior of the mHEMT device.
System requirements: World Wide Web browser and PDF reader.
Mode of access: World Wide Web.

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46

BANDI, DILIP KUMAR. "Small Signal Impedance and Optical Modulation Bandwidth Characterization and Modeling of Organic Light Emitting Devices." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1204912125.

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Miri, Seyed-Mehdi. "Modeling and fault detection in electromagnetic devices : applications to synchronous machines and signal conditioning systems /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487332636476273.

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48

Baldwin, Kevin. "Computer aided design and simulation of an integrated photonic delay line system for phased array antenna and other microwave signal processing applications /." Online version of thesis, 1993. http://hdl.handle.net/1850/11081.

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49

Fraser, David Raye. "Implementation of a modal filtering procedure." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28382.

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A FORTRAN program has been developed in order to investigate the process of modal parameter estimation and non-parametric system identification. The theory underlying the process of modal parameter estimation is reviewed and the decoupling of a MIMO system into several SISO systems is demonstrated. Modal filtering is shown to be useful in the field of non-parametric system identification and it is shown that it may also be of some use in the field of signal processing. The program is documented. It simulates the output of a n-th order system from which a smaller order subsystem can be decoupled. The modal parameters of a subsystem output signal and its first two derivatives and the modal parameters of a second subsystem output and its first derivative are calculated. The unit step response of the theoretical system and the subsystem are then calculated. The signals are then modal filtered to produce the periodic unit step response and the periodic unit square wave response. Finally, the discrete Fourier coefficients of the periodic unit step response are calculated.
Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate

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50

Drew, Stephen. "Symmetric Gain Optoelectronic Mixers for LADAR Applications." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/DrewS2009.pdf.

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Dissertations / Theses on the topic 'Signal devices'

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