Friction is one of the essential aspects of pavement performance and safety. Unfortunately, the rate at which the friction data are being collected exceeds the rate at which the data can be proficiently analyzed. Furthermore, the Utah Department of Transportation (UDOT) lacks long-term trend analysis for the many years of locked-wheel skid trailer (LWST) data collected in Utah. In addition, UDOT is missing a statistically adequate correlation equation between friction-testing devices. Likewise, only one method is used in Utah to prequalify aggregates for use in pavements. Finally, there has not been an investigation of the potential use of lithium silicate solution in Utah as a hardening agent to decrease the rate of friction loss. This research consists of five objectives. The first objective was to investigate pavement friction factors that influence skid resistance; methods of measuring skid resistance in the laboratory and the field, including correlations between test results; methods of evaluating aggregate sources; and methods of enhancing skid resistance of asphalt pavements through a comprehensive literature review on these subjects. The second objective was to investigate temporal trends in skid numbers measured using the LWST on Utah highways with different surface treatment types. The third objective was to develop a three-way correlation between the skid number measured with the LWST in the field, the British pendulum number measured with the British pendulum tester (BPT) in the field, and the polish value measured with the BPT in the laboratory. The fourth objective was to investigate selected performance-related properties of aggregates used to produce surface treatments at several field sites representing Utah conditions. The fifth objective was to examine the potential benefits of lithium silicate treatment for improving the resistance of aggregates to polishing. The scope of the research for the five objectives included statistical analysis, field testing, and laboratory experimentation. The findings include, first, a literature review that identified four critical deficiencies in Utah’s friction-related literature, which formed the basis of the remaining four objectives. Second, a statistical analysis of 9 years of LWST data indicated above-average skid values across Utah’s pavement network. Third, correlations were evaluated for multiple friction-testing devices. Fourth, X-ray diffraction testing methods were found to compare favorably to the accelerated polish test. Fifth and finally, the effects of lithium silicate solution on polish-susceptible aggregates were documented. This research has substantially advanced the body of knowledge on pavement friction testing and improving the resistance of aggregates to polishing in Utah through laboratory and field experimentation

I denna studie kommer det att undersökas hur SIS LVM-hem och behandlingshemarbetar med kvinnliga klienter inför en § 27 placering. Att förbereda enmissbrukare inför behandling kan utspela sig på flera olika sätt i Sverige. Därmissbrukare som befinner sig i ett missbruk kan bli tvångsomhänderta ochplacerade på låst behandling ifall deras missbruk har gått till den gränsen attindividen utsätter sin hälsa för så pass allvarlig fara så att det kan leda till att denavlider. När en individ placeras på låst behandling är avsikten att den skaförberedas succesivt för behandling i öppnare former enligt §27. I denna studiehar jag valt att studera ett perspektiv som involverar hur Statensinstitutionsstyrelse LVM-hem för kvinnor och ett behandlingshem arbetar med attanpassa övergången från låst behandling till öppet behandlingshem. Dåmissbruksvården är bred och de finns olika former av låsta behandlingar ochöppna behandlingar så föll valet på SIS LVM-hem för kvinnor ochbehandlingshem. Valet av avgränsning till kvinnor är på grund att som (Statensinstitutionsstyrelse (2020) redovisar är kvinnor mera utsatta än männen när dethamnar i ett drogmissbruk.I studien utformades 11 semistrukturerade intervjuer där sex var från SIS LVMhem och fem från behandlingshem. Valet av teoretiskt perspektiv föll påsamverkansteori, coping och socialt nätverk. I resultatet framkommer det att medkontinuerlig och strategisk samverkan kan missbruksvården förbättra övergångenfrån låst behandling till öppet behandlingshem. De berörda enheterna som arbetarmed missbrukaren bör gemensamt studera klientensbehov med avsikten för attförstärka deras coping strategier så att klienten bygger upp en resiliens motmissbruk. Genom att studera klienters sociala nätverk kan man kartlägga vilkenpåverkan de olika individerna har i klientens nätverk för att vägleda de tillpositiva förebilder så det upprätthåller nykterhet efter att behandlingen är klar. / In this study I will research Sis LVM-home and treatment home works withfemale drug addicts for a placement according to § 27. To prepare a drug addictfor treatment have different approaches in Sweden. Where if the drug addict is ina serious drug addiction they can be forcibly acquired and placed in a locked drugtreatment institution before they can start their treatment in more open treatmentoptions according to § 27.Based on that I have chosen to study how staff work from the lockedrehabilitation facilities, Statens institutionsstyrelse LVM-hem for women and onetreatment home. Works with the transition from locked rehab facilities to openfacility paragraph § 27 for women from 18 years and above. Due to the broaddrug treatment in Sweden where there are many kinds of forms of locked facilitiesand open facilities, I have chosen SIS LVM-homes and treatment home wherethey live. The reason why I chose to study women drug addicts is based on(Statens institutionsstyrelse (2020) that they are in general more exposed thanmen during drug addiction.In this study, I have conducted 11 semi structured interviews where six are fromSIS LVM-homes and five from treatment home. The choice of theoreticalperspective is cooperation, coping and social network. As stated in the results,with a continuous strategic cooperation you can improve the transaction fromlocked to open facility. Where it is important that the concerned units commonlystudy the client's needs with the intention to improve the clients' coping strategiesso they can build up a resilience against drug addiction. By studying the socialnetwork, one can chart what kind of impact different kind of individuals have onthe client’s social network. This is used to guide the drug addicted person towhich people have a good impact on them so they can maintain a life sober whenthe rehab is done.

Completely locked-in state (CLIS) patients are unable to speak and have lost all muscle movement. From the external view, the internal brain activity of such patients cannot be easily perceived, but CLIS patients are considered to still be conscious and cognitively active. Detecting the current state of consciousness of CLIS patients is non-trivial, and it is difficult to ascertain whether CLIS patients are conscious or not. Thus, it is important to find alternative ways to re-establish communication with these patients during periods of awareness, and one such alternative is through a brain–computer interface (BCI). In this study, multiscale-based methods (multiscale sample entropy, multiscale permutation entropy and multiscale Poincaré plots) were applied to analyze electrocorticogram signals from a CLIS patient to detect the underlying consciousness level. Results from these different methods converge to a specific period of awareness of the CLIS patient in question, coinciding with the period during which the CLIS patient is recorded to have communicated with an experimenter. The aim of the investigation is to propose a methodology that could be used to create reliable communication with CLIS patients.

No description available.

The unconventional improvements in the power electronics field have been the primary reason for massive deployment of renewable energy sources in the electrical power grid over the past several decades. This needed trend, together with the increasing penetration of micro-, and nano- grids, is bringing significant improvements in system controllability, performance, and energy availability, but is fundamentally changing the nature of electronically-interfaced sources and loads, altering their conventionally mild aggregate dynamics, and inflicting low- and high- frequency dynamic interactions that never before existed at this magnitude. This problem is not restricted only to the grid; modern electronic power distribution systems built for airplanes, ships, electric vehicles, data-centers, and homes, comprise dozens, even hundreds of power electronics converters, produced by different manufacturers, who provide very limited details on converters' dynamic behavior - distinctiveness that has the highest impact on how two converters, or converter and a system interact. Consequently, substantial dispersion of power electronics into the future grid will significantly depend on engineers' capability to understand how to model and dynamically control power flow and subsystem interactions. It is therefore essential to continue developing innovative methods that allow easier system-level modeling, continuous monitoring of dynamic interactions, and advanced control concepts of power electronics converters and systems. The dissertation will start with a "black box" approach to modeling of three-phase power electronics converters, introducing a method to remove source and load dynamics from in-situ measured terminated frequency responses. It will be then shown how converter, itself, can perform an online stability assessment knowing its own unterminated dynamics, and being able to measure all terminal immittances. The dissertation will further advance into an approach to control power electronics converters based on the electro-mechanical duality with synchronous machines, and end with selected examples of system-level operation, where small-signal instability in multi-source power systems can be mitigated using this concept. / Ph. D. / The modern technological advancements and ever-increasing needs for a sustainable future silently demand a serious revision of the conventional practice in electricity production, distribution, and utilization. These technologies are already challenging the limits of the biggest and most complex system ever built by humankind - the electrical grid. One practical solution to this problem is much higher dispersion of electronic power conversion systems capable of decoupling dynamics between system sources, distribution, and loads, while improving system controllability, reliability, and efficiency. Such a trend is already happening, and there has been an increased immersion of power electronics converters in electric cars, ships, airplanes, and the grid, in an effort to replace their traditional thermal, mechanical, hydraulic, and pneumatic systems. The goals have been to reduce the size, weight, and operational costs while increasing efficiency and reliability. In all these applications, a majority of energy sources and loads are interfaced to the power system through power electronics converters ranging in power from few watts to hundreds of megawatts. However, massive dispersion of power electronics into the future grid will significantly depend on engineers’ capability to understand how to model and dynamically control power flow and subsystem interactions. It is important to continue researching innovative methods that allow easier system-level modeling, continuous monitoring of interactions, and advanced control concepts of power electronics converters and systems. This dissertation hence addresses modeling of power electronics converters using their behavioral models, and shows how these models can assist the stability assessment of the system converters operate in. Additionally, dissertation presents an alternative way to control power electronics converters to behave as synchronous machines, and how this concept can be used to mitigate some stability problems.

This thesis focuses on analyzing the synchronization of time delays between mutually coupled phase-locked loops (PLLs) in a flat hierarchy. Mutual synchronization refers to decentralized synchronization where there is no primary or secondary unit or control source. Consequently, it is an inherently self-organizing system in which each unit has equal rights, making it a democratic system. In this research, a dynamic nonlinear time-domain model is used to describe mutually delayed coupled oscillators. The predictions of this model are evaluated against experimental measurements. The time-domain model is based on the Kuramoto model. The Kuramoto model describes a network of coupled oscillators. As a first impression, this Kuramoto model is first analyzed for understanding of the effects of time delays between oscillators. The time domain model is based on a conventional PLL architecture modified to allow mutual coupling. The modifications include a circuit section that sums and weights all incoming phase differences. Overall, the measured results of this research study are in good agreement with the theoretical predictions of the time-domain model. The analysis allows the identification of the transient dynamics and the mechanisms that lead to mutual coupling and the formation of synchronized states through self-organized synchronization. The results show that the mutual coupling can self-organize its dynamics to synchronize even at time delays where the phenomenon of multistability of synchronized states occurs. A critical time delay beyond which a stable synchronized state cannot be achieved has been identified. The work also analyzes the dynamics and noise of synchronized states and finds that the dynamics near a synchronized state are correlated due to mutual coupling, leading to a reduction in noise. The noise correlation is affected by the direction of coupling, the number of nodes in the network, and the network topology. An improvement in phase noise of up to 14.42 dBc/Hz at 100 kHz offset from the carrier and 49.47ns delay was achieved using all-to-all coupling with four nodes. Furthermore, the hybrid approach, the combination of hierarchical and self-organizing synchronization architectures, is investigated. The dissertation presents an experimental study to understand how this affects a network of mutually delayed delay-coupled oscillators and whether the network of mutually coupled nodes can be abstracted as a secondary oscillator. A range in which the mutually delay-coupled network can be successfully synchronized by an external reference oscillator, depending on the synchronized state, is identified. In summary, this thesis provides valuable insights into the properties of mutually delay-coupled PLLs and their synchronization in flat hierarchies, and contributes to the understanding, design, and optimization of more practical networks of mutually delayed PLLs.:Abstract/Zusammenfassung Symbols and Abbreviations Previous Publications 1 Introduction 1.1 Classifications of Synchronization 1.2 A Historical Perspective on Mutual Synchronization 1.3 Extending the Understanding of Mutual Synchronization 1.4 Definitions and Methodologies 2 Model of Networks of Mutually Coupled PLLs 2.1 Coupled Oscillators – Kuramoto Model 2.1.1 Consequences of a Time Delay between Oscillators 2.1.2 Arbitrary Time Delays between Oscillators 2.2 Time-Domain Model of Delay-Coupled PLLs 2.2.1 Phase Detection 2.2.2 Loop-Filter 2.2.3 Voltage Controlled Oscillator 2.3 Prediction and Stability Analysis of Synchronized States 2.3.1 Assessing the Linear Stability of Synchronized States 2.3.2 Stability Consideration for Two Identical PLL Nodes 2.3.3 The Notion of Mode Locking 2.3.4 Effects of Heterogeneity on Synchronized States 2.4 Dynamics and Noise in Synchronized States 2.4.1 Gain and Phase Margin of a PLL Node 2.4.2 Phase Noise 2.5 Key Findings of the Theoretical Model 3 Design of Phase-Locked-Loops for Mutual Synchronization 3.1 PLL Nodes Dedicated for Mutual Synchronization 3.1.1 Phase Detection Circuitry 3.1.2 Adder Chain 3.2 Additional Circuitry for Implementing a Time Delay 4 Experimental Analysis of Mutually Time-Delayed Coupled PLLs 4.1 Synchronized States Including Oscillator Nonlinearity 4.2 Stability of Multistable Synchronized States 4.3 Critical Time Delay Between Two Coupled Nodes 4.4 Combining Hierarchical and Flat Synchronization Concepts 4.4.1 Entrainment of a Chain Network Topology 4.4.2 Entrainment of a Ring Network Topology 4.5 Heterogeneous Time Delays between Coupled PLLs 4.6 Phase Noise Analysis of Time Delay Coupled PLLs 4.6.1 Phase Noise for Two Mutually Coupled Nodes 4.6.2 The Impact of Coupling Directionality 4.6.3 Long Term Frequency Stability 4.6.4 Effect of Time Delay on Phase Noise 4.6.5 Network Topology Dependency on Phase Noise 5 Conclusion and Future Prospects Bibliography Own Publications – Periodicals Own Publications – Conference Proceedings Co-Authored Publications Other References List of Figures List of Tables Acknowledgement Curriculum Vitae / Diese Arbeit befasst sich mit der Analyse der Auswirkungen von Zeitverzögerungen auf die Synchronisation von gegenseitig gekoppelten Phasenregelschleifen (engl. phase-locked loop (PLL)) in einer flachen Hierarchie. Gegenseitige Synchronisation bezieht sich auf eine dezentrale Synchronisation, bei der es keine primäre oder sekundäre Einheit oder Steuerquelle gibt. Folglich ist es ein inhärent selbstorganisierendes System, in dem jede Einheit gleichberechtigt ist, was es zu einem demokratischen System macht. Für die Untersuchung wird ein dynamisches nichtlineares Zeitbereichsmodell verwendet, um gegenseitig verzögert gekoppelte Oszillatoren zu modellieren und die Vorhersagen dieses Modells anhand experimenteller Messungen zu bewerten. Dieses Zeitbereichsmodell basiert auf dem sogenannten Kuramoto-Modell, das ein Netzwerk gekoppelter Oszillatoren beschreibt. Um einen ersten Eindruck zu erhalten, wird zunächst dieses Kuramoto-Modell analysiert, um die Auswirkungen von Zeitverzögerungen zwischen den Oszillatoren zu verstehen. Das Zeitbereichsmodell basiert auf einer konventionellen PLL-Architektur, die modifiziert wurde, um eine gegenseitige Kopplung zu ermöglichen. Die Modifikationen beinhalten einen Schaltungsteil, der alle eingehenden Phasendifferenzen summiert und gewichtet. Die gemessenen Ergebnisse dieser Untersuchung stimmen insgesamt gut mit den theoretischen Vorhersagen des Zeitbereichsmodells überein. Die Analyse erlaubt es, die transiente Dynamik und die Mechanismen zu identifizieren, die zur gegenseitigen Synchronisation und zur Bildung synchronisierter Zustände durch selbstorganisierte Synchronisation führen. Die Ergebnisse zeigen, dass selbst bei Zeitverzögerungen, bei denen das Phänomen der Multistabilität synchronisierter Zustände auftritt, die gegenseitige Kopplung ihre Dynamik selbst organisieren kann, um sich zu synchronisieren. Die Untersuchung identifizierte eine kritische Zeitverzögerung, bei der kein stabiler synchronisierter Zustand erreicht werden kann. Die Arbeit analysiert auch die Dynamik und das Rauschen von synchronisierten Zuständen und stellt fest, dass die Dynamik in der Nähe eines synchronisierten Zustands aufgrund der gegenseitigen Kopplung korreliert ist, was zu einer Reduktion des Rauschens führt. Die Richtung der Kopplung und die Anzahl der Knoten im Netzwerk sowie die Netzwerktopologie beeinflussen die Korrelation des Rauschens. Eine Verbesserung des Phasenrauschens von bis zu 14.42 dBc/Hz bei einem Versatz von 100 kHz zum Träger und einer Verzögerung von 49.47 ns wurde durch eine globalen oder All-to-All-Kopplung mit vier Knoten erreicht. Des Weiteren wird der hybride Ansatz, die Kombination von hierarchischen und selbstorganisierenden Synchronisationsarchitekturen, untersucht. Die Arbeit präsentiert eine experimentelle Studie, um zu verstehen, wie dies ein Netzwerk von gegenseitig verzögert gekoppelten Oszillatoren beeinflusst und ob das Netzwerk von gegenseitig gekoppelten Knoten als sekundärer Oszillator abstrahiert werden kann. Dabei wird eine vom synchronisierten Zustand abhängige Domäne identifiziert, in der das wechselseitig gekoppelte Netzwerk durch einen externen Referenzoszillator erfolgreich synchronisiert werden kann. Insgesamt liefert diese wissenschaftliche Arbeit wertvolle Erkenntnisse über die Eigenschaften von gegenseitig verzögerungsgekoppelten PLLs und deren Synchronisation in einer flachen Hierarchie und trägt zum Verständnis, zum Entwurf und zur Optimierung von praktisch realisierten Netzwerken gegenseitig verzögerungsgekoppelter PLLs bei.:Abstract/Zusammenfassung Symbols and Abbreviations Previous Publications 1 Introduction 1.1 Classifications of Synchronization 1.2 A Historical Perspective on Mutual Synchronization 1.3 Extending the Understanding of Mutual Synchronization 1.4 Definitions and Methodologies 2 Model of Networks of Mutually Coupled PLLs 2.1 Coupled Oscillators – Kuramoto Model 2.1.1 Consequences of a Time Delay between Oscillators 2.1.2 Arbitrary Time Delays between Oscillators 2.2 Time-Domain Model of Delay-Coupled PLLs 2.2.1 Phase Detection 2.2.2 Loop-Filter 2.2.3 Voltage Controlled Oscillator 2.3 Prediction and Stability Analysis of Synchronized States 2.3.1 Assessing the Linear Stability of Synchronized States 2.3.2 Stability Consideration for Two Identical PLL Nodes 2.3.3 The Notion of Mode Locking 2.3.4 Effects of Heterogeneity on Synchronized States 2.4 Dynamics and Noise in Synchronized States 2.4.1 Gain and Phase Margin of a PLL Node 2.4.2 Phase Noise 2.5 Key Findings of the Theoretical Model 3 Design of Phase-Locked-Loops for Mutual Synchronization 3.1 PLL Nodes Dedicated for Mutual Synchronization 3.1.1 Phase Detection Circuitry 3.1.2 Adder Chain 3.2 Additional Circuitry for Implementing a Time Delay 4 Experimental Analysis of Mutually Time-Delayed Coupled PLLs 4.1 Synchronized States Including Oscillator Nonlinearity 4.2 Stability of Multistable Synchronized States 4.3 Critical Time Delay Between Two Coupled Nodes 4.4 Combining Hierarchical and Flat Synchronization Concepts 4.4.1 Entrainment of a Chain Network Topology 4.4.2 Entrainment of a Ring Network Topology 4.5 Heterogeneous Time Delays between Coupled PLLs 4.6 Phase Noise Analysis of Time Delay Coupled PLLs 4.6.1 Phase Noise for Two Mutually Coupled Nodes 4.6.2 The Impact of Coupling Directionality 4.6.3 Long Term Frequency Stability 4.6.4 Effect of Time Delay on Phase Noise 4.6.5 Network Topology Dependency on Phase Noise 5 Conclusion and Future Prospects Bibliography Own Publications – Periodicals Own Publications – Conference Proceedings Co-Authored Publications Other References List of Figures List of Tables Acknowledgement Curriculum Vitae

Un microscope à force atomique (AFM) est utilisé pour caractériser des matériaux isolant ou semi-conducteur avec une résolution pouvant atteindre l'échelle atomique. Ce microscope est constitué d'un capteur de force couplé à une électronique de contrôle pour pouvoir correctement caractériser ces matériaux. Parmi les différents modes (statique et dynamique), nous nous focalisons essentiellement sur le mode dynamique et plus particulièrement sur le fonctionnement sans contact à modulation de fréquence (FM-AFM). Dans ce mode, le capteur de force est maintenu comme un oscillateur harmonique par le système d'asservissement. Le projet ANR Pnano2008 intitulé : ”Cantilevers en carbure de silicium à piézorésistivité métallique pour AFM dynamique à très haute fréquence" a pour objectif d'augmenter significativement les performances d'un FM-AFM en développant un nouveau capteur de force très haute fréquence. Le but est d'augmenter la sensibilité du capteur et de diminuer le temps nécessaire à l'obtention d'une image de la surface du matériau. Le système de contrôle associé doit être capable de détecter des variations de fréquence de 100mHz pour une fréquence de résonance de 50MHz. Etant donné que les systèmes présents dans l'état de l'art ne permettent pas d'atteindre ces performances, l'objectif de cette thèse fut de développer un nouveau système de contrôle. Celui-ci est entièrement numérique et il est implémenté sur une carte de prototypage basée sur un FPGA. Dans ce mémoire, nous présentons le fonctionnement global du système ainsi que ses caractéristiques principales. Elles portent sur la détection de l'écart de fréquence de résonance du capteur de force. / An atomic force microscope (AFM) is used to characterize insulating materials or semiconductors with a resolution up to the atomic length scale. The microscope includes a force sensor linked to a control electronic in order to properly characterize these materials. Among the various modes (static and dynamic), we focus mainly on the dynamic mode and especially on the frequency modulation mode (FM-AFM). In this mode, the force sensor is maintained as a harmonic oscillator by the servo system. The research project ANR Pnano2008 entitled: "metal piezoresistivity silicon carbide cantilever for very high frequency dynamic AFM" aims to significantly increase the performance of a FM-AFM by developing new very high frequency force sensors. The goal is to increase the sensitivity of the sensor and to decrease the time necessary to obtain topography images of the material. The control system of this new sensor must be able to detect frequency variations as small as 100mHz for cantilevers with resonance frequencies up to 50MHz. Since the state-of-the-art systems doe not present these performances, the objective of this thesis was to develop a new control system. It is fully digital and it is implemented on a FPGA based prototyping board. In this report, we present the system overall functioning and its main features which are related to the cantilever resonant frequency detection. This detection is managed by a phase locked loop (PLL) which is the key element of the system.

Ce travail de thèse présente une étude sur les propriétés de nanostructures de type bâtonnets quantiques et de leur application pour les télécommunications optiques. Durant la dernière décennie, ces nanostructures, ont démontré des propriétés optiques et électroniques intéressantes en raison notamment d’un fort confinement quantique dans les trois dimensions d'espace. Cette thèse porte sur la conception et la fabrication d'émetteurs optiques intégrés à base de ce matériau et de leur implémentation dans des systèmes de communication. La première partie de ce travail analyse les propriétés de ces nanostructures, théorique et expérimentale. Elles sont utilisées comme matériau actif de lasers modulés directement en amplitude. Les propriétés dynamiques de ces lasers sont ensuite évaluées et des transmissions sur fibre optique entre 0 et 100 km sont ensuite démontrées en utilisant un filtre étalon permettant d’augmenter en particulier le taux d’extinction dynamique. En s’appuyant sur cette démonstration basée sur des éléments discrets, une version monolithique intégrant un laser et un résonateur en anneaux a été réalisée. La dernière partie de ce travail porte sur des lasers à blocage de mode à base de ce matériau et en particulier sur les méthodes d’intégration sur substrat InP. En particulier, un design de miroir de Bragg innovant a été développé à cet effet et une démonstration d'un laser a blocage de mode intégré avec un amplificateur optique à semi-conducteur a finalement été réalisée / This PhD dissertation presents a study on the properties of the novel quantum dash nanostructures and their properties for application in optical telecommunications. Over the last decade, scientific community has gained considerable interest over these nanostructures and several demonstrations have been made on their interesting optical and electronic properties, notably owing to their strong quantum confinement. This dissertation focuses on conception, fabrication and system demonstration of integrated optical transmitters based on quantum dash material. A first part of this work analyses the properties of qdashes theoretically and experimentally for their use as an active material in directly modulated lasers. The dynamic properties of this material are then evaluated leading to an optical transmission distances in range of 0-100km under direct modulation. The transmission is particularly studied with a passive optical filter to enhance the dynamic extinction ratio, the use of such passive filters is studied in detail. An innovative and fully integrated optical transmitter is finally demonstrated by integrating a ring-resonator filter to a distributed feedback laser. The second part of this work focuses on mode locked lasers based on this material and in particular the methods of integration of such devices on InP are explored. Thus an innovative Bragg mirror design is developed leading to a mode locked laser integrated with a semiconductor optical amplifier

Integrated systems with billions of transistors on a single chip are a now reality. These systems include multi-core microprocessors and are built today using deca-nanometer devices organized into synchronous digital circuits. The movement of data within such systems is regulated by a set of predictable timing signals, called clocks, which must be distributed to a large number of sequential elements. Collectively, these clocks have a significant impact on the frequency of operation and, consequently, on the performance of the systems. The clocks are also responsible for a large fraction of the power consumed by these systems. The objective of this dissertation is to better understand clock distribution in order to identify opportunities and strategies for improvement by analyzing the conditions under which the optimal tradeoff between power and performance can be achieved, by modeling the constraints associated with local and global clocking, by evaluating the impact of noise, and by investigating promising new design strategies for future integrated systems.

This thesis presents the analysis, design and characterization of an integrated high-frequency phase-locked loop (PLL) frequency multiplier. The frequency multiplier is novel in its use of a low multiplication factor of 4 and a fully differential topology for rejection of common mode interference signals. The PLL is composed of a voltage controlled oscillator (VCO), injection-locked frequency divider (ILFD) for the first divide-by-two stage, a static master-slave flip-flop (MSFF) divider for the second divide-by-two stage and a Gilbert cell mixer phase detector (PD). The circuit has been fabricated using a standard CMOS 0.18-um process based on its relatively low cost and ready availability. The PLL frequency multiplier generates an output signal at 26 GHz and is the highest operational frequency PLL in the technology node reported to date. Time domain phase plane analysis is used for prediction of PLL locking range based on initial conditions of phase and frequency offsets. Tracking range of the PLL is limited by the inherent narrow locking range of the ILFD, and is confirmed via experimental results. The performance benefits of the fully differential PLL are experimentally confirmed by the injection of differential- and common-mode interfering signals at the VCO control lines. A comparison of the common- and differential-mode modulation indices reveals that a common mode rejection ratio (CMRR) of greater than 20 dB is possible for carrier offset frequencies of less than 1 MHz. Closed-loop frequency domain transfer functions are used for prediction of the PLL phase noise response, with the PLL being dominated by the reference and VCO phase noise contributions. Regions of dominant phase noise contributions are presented and correlated to the overall PLL phase noise performance. Experimental verifications display good agreement and confirm the usefulness of the techniques for PLL performance prediction. The PLL clock multiplier has an operational output frequency of 26.204 to 26.796 GHz and a maximum output frequency step of 16 MHz. Measured phase noise at 1 MHz offset from the carrier is -103.9 dBc/Hz. The PLL clock multiplier core circuit (VCO/ILFD/MSFF Divider/PD) consumes 186 mW of combined power from 2.8 and 4.3 V DC rails. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2009-04-24 11:31:35.384