There has been a huge rise in interest in the design of energy efficient wireless sensor networks (WSN) and body area networks (BAN) with the advent of many new applications over the last few decades. The number of sensor nodes in these applications has also increased tremendously in the order of few hundreds in recent years. A typical sensor node in a WSN consists of circuits like RF transceivers, micro-controllers or DSP, ADCs, sensors, and power supply circuits. The RF transmitter and receiver circuits mainly the frequency synthesizers(synthesis of RF carrier and local oscillator signals in transceivers) consume a significant percentage of its total power due to its high frequency of operation. A charge-pump phase locked loop (CP-PLL) is the most commonly used frequency synthesizer architecture in these applications. The growing demands of WSN applications, such as low power consumption larger number of sensor nodes, single chip solution, and longer duration operation presents several design challenges for these transmitter and frequency synthesizer circuits in these applications and a few are listed below, Low power frequency synthesizer and transmitter designs with better spectral performance is essential for an energy efficient operation of these applications. The spurious tones in the frequency synthesizer output will mix the interference signals from nearby sensor nodes and from other interference sources present nearby ,to degrade the wireless transmitter and receiver performance[1]. With the increased density of sensor nodes (more number of in-band interference sources) and degraded performance of analog circuits in the nano-meter CMOS process technologies, the spur reduction techniques are essential to improve the performance of frequency synthesizers in these applications. A single chip solution of sensor nodes with its analog and digital circuits integrated on the same die is preferred for its low power, low cost, and reduced size implementation. However, the parasitic interactions between these analog and digital sub-systems integrated on a common substrate, degrade the spectral performance of frequency synthesizers in these implementations[2]. Therefore, techniques to improve the mixed signal integration performance of these circuits are in great demand. In this thesis, we present a custom designed energy efficient 2.4 GHz BFSK/ASK transmitter architecture using a low power frequency synthesizer design technique taking advantage of the CMOS technology scaling benefits. Furthermore, a few design guidelinesandsolutionstoimprovethespectralperformanceoffrequency synthesizer circuits and in-turn the performance of transmitters are also presented. The target application being short distance, low power, and battery operated wireless communication applications. The contributions in this thesis are, Spectral performance improvement techniques The CP mismatch current is a dominant source of reference spurs in the nano-meter CMOS PLL implementations due to its worsened channel length modulation effect [3]. In this work, we present a CP mismatch current calibration technique using an adaptive body bias tuning of its PMOS transistors. Chip prototype of 2.4 GHzCP-PLLwith the proposed CP calibration technique was fabricated in UMC 0.13 µm CMOS process. Measurements show a CP mismatch current of less than 0.3 µA(0.55 %) using the proposed calibration technique over the VCO control voltage range 0.3 to 1 V. The closed loop PLL measurements using the proposed technique exhibited a 9dB reduction in the reference spur levels across the PLL output frequency range 2.4 -2.5 GHz. The parasitic interactions between analog and digital circuits through the common substrate severely affects the performance of CP-PLLs. In this work, we experimentally demonstrate the effect of periodic switching noise generated from the digital buffers on the performance of charge-pump PLLs. The sensitivity of PLL performance metrics such as output spur level, phase noise, and output jitter are monitored against the variations in the properties of a noise injector digital signal. Measurements from a 500 MHz CP-PLL shows that the pulsed noise injection with the duty cycle of noise injector signal reduced from 50% to 20%, resulted in a 12.53 dB reduction in its output spur level and a 107 ps reduction in its Pk-Pk deterministic period jitter performance. Low power circuit techniques A low power frequency synthesizer design using a digital frequency multiplication technique is presented. The proposed frequency multiply by 3 digital edge combiner design having a very few logic gates, demonstrated a significant reduction in the power consumption of frequency synthesizer circuits, with an acceptable spectral performance suitable for these relaxed performance applications. A few design guidelines and techniques to further improve its spectral performance are also discussed and validated through simulations. Chip prototypes of 2.4 GHz CP-PLLs with and without digital frequency multiplier circuits are fabricated in UMC 0.13 µm CMOS process. The 2.4 GHz CP-PLL using the proposed digital frequency multiplication technique (10.7 mW) consumed a much reduced power compared to a conventional implementation(20.3 mW). A custom designed, energy efficient 2.4 GHz BFSK/ASK transmitter architecture using the proposed low power frequency synthesizer design technique is presented. The transmitter uses a class-D power amplifier to drive the 50Ω antenna load. Spur reduction techniques in frequency synthesizers are also used to improve the spectral performance of the transmitter. A chip prototype of the proposed transmitter architecture was implemented in UMC0.13 µm CMOS process. The transmitter consume14 mA current from a 1.3V supply voltage and achieve improved energy efficiencies of 0.91 nJ/bit and 6.1 nJ/bit for ASK and BFSK modulations with data rates 20Mb/s & 3Mb/s respectively.

With the move of the broadband cellular network towards 5G taking off and the preparatory work on 6G and beyond starting, the need for low-complexity, low-power, and high-performance frequency synthesis using Phase-Locked Loop (PLL)s increases. As we get deeper into the mm-wave frequencies and push towards frequencies in the order of 50-70 GHz design challenges with existing PLL architectures, such as limited technology scaling and limited in-band noise performance become more apparent. Other designs have tried overcoming these problems, for example by using single-bit phase detection at the cost of increased complexity when trying to control the bandwidth, or designing the loop with lower bandwidth to suppress in-band noise at the cost of requiring a lower noise and thus more power hungry oscillator. This thesis proposes a new Phase-locked loop architecture implemented in a 22nm node to combat these issues, utilizing a Pulse-Shrinking Time-To-Digital Converter (PS-TDC) offering sub-pico-second resolution with minimal power consumption in lock. The results found in this thesis have shown the viability of such a design, offering good in-band performance, allowing for wide bandwidth, and the use of a cheaper low-power Digital-Controlled Oscillator (DCO). The PS-TDC architecture combined with control logic implemented in this project can drastically decrease power consumption in lock while being able to compensate for process variations to optimize jitter performance. Additionally, by utilizing a Phase-Frequency Detector (PFD) and gear-shifting logic it has been shown that robust and fast locking can be achieved. / Med övergången till 5G i mobila bredbandsnätverk och förberedelserna för 6G på gång ökar behovet av lågkomplexa, lågeffekts- och högpresterande frekvenssyntes. När vi beger oss djupare in i millimetervågsfrekvenserna och strävar efter frekvenser uppemot 50-70 GHz blir designutmaningar med befintliga faslåsta loopar, såsom begränsad teknologiskalning och dålig prestanda för inband-brus, alltmer tydliga. Andra designer har försökt att övervinna dessa problem genom att till exempel använda enbitars fasdetektion till priset av ökad komplexitet vid styrning av systemets bandbredd, eller genom att designa loopen med lägre bandbredd för att vidare dämpa inband-brus, vilket kommer till priset av en oscillator med lägre brus och därmed högre effektförbrukning. Denna avhandling föreslår en ny arkitektur för faslåsta loopar för att överkomma dessa problem genom att använda en pulskrympande tids-till-digital omvandlare som erbjuder sub-pikosekunds upplösning med minimal effektförbrukning när frekvensen är låst. Resultaten som presenteras i denna avhandling har visat att en sådan design är möjlig, med god in-band prestanda, möjlighet till hög bandbredd och därmed användning av en billigare lågeffekt DCO. Den pulsskalande TDC-arkitekturen i kombination med kontrolllogik implementerad i detta projekt kan dramatiskt minska effektförbrukningen när frekvensen är låst, samtidigt som den kan kompensera för processvariationer för att optimera jitterprestanda. Sist har det visats att en robust och snabb låsning av frekvensen kan uppnås genom att använda en PFD.

Die vorliegende Dissertation behandelt das Zusammenspiel von effizienten aktiven Lasermedien und neuartigen sättigbaren Absorbern, welche auf den Kohlenstoff-Nanostrukturen Graphen und den einwandigen Kohlenstoff Nanoröhren (SWCNTs) basieren. Die aktiven Lasermedien decken den Spektralbereich von 1,0 Mikrometer bis 2,1 Mikrometer ab, d.h. eine ganze Oktave, und nutzen die laseraktiven Ionen des Ytterbiums, Chroms und Thuliums. In dieser Arbeit werden die auf Graphen und SWCNT basierenden sättigbaren Absorber hinsichtlich ihres einer Anregung folgenden Relaxationsverhaltens, ihrer von der Fluenz abhängigen Transmission und ihres Sättigungs- verhaltens bei hohen Fluenzen untersucht. Eine vorangestellte Einführung der optischen Eigenschaften von Graphen und SWCNTs wird gegeben und die Modelle zur Beschreibung realer Proben werden aus theoretischen Modellvorstellungen hergeleitet. Die sättigbaren Absorber basierend auf Graphen und SWCNTs werden untereinander und mit klassischen halbleitenden sättigbaren Absorbern verglichen. Diese Arbeit zeigt ferner die Erzeugung ultrakurzer Pulse verschiedener Laser mit diesen neuartigen sättigbaren Absorbern basierend auf Kohlenstoff Nanostrukturen. Die erhaltenen Pulse werden mittels Spektrometrie, Autokorrelation, Radiofrequenz- und partiell FROG-Messungen charakterisiert, und der zugrunde liegende Pulsformungsmechanismus, sowie die Stabilität gegen das Güteschalten werden diskutiert. / This thesis addresses the interplay of highly efficient active laser media and novel saturable absorbers based on the carbon nanostructures graphene and single-walled carbon nanotubes (SWCNTs). The active laser media cover the spectral region from 1.0 micron up to 2.1 micron, i.e. a whole octave, and apply ytterbium, chromium and thulium as active lasing ions. Within this work, the saturable absorbers based on SWCNTs and graphene are characterized with respect to their relaxation behaviour after excitation, and with respect to their fluence-dependent transmission and saturation. A precedent introduction of the general optical properties of graphene and SWCNTs is presented as well and the models to describe real samples experimentally are deduced from theoretical model conceptions. The saturable absorbers based on graphene and SWCNTs are compared to each other and to classical semiconducting saturable absorbers. This thesis further presents the generation of ultrashort laser pulses applying these novel carbon nanostructure based saturable absorbers in different lasers. The obtained pulses are characterized by spectrometry, autocorrelation, radio-frequency measurements and partially by FROG measurements. Additionally, the underlying pulse formation process and the Q-switching stability are discussed.

Systeme mit Zeitverzögerung sind von großem Interesse in Nichtlinearer Dynamik und allgegenwärtig in den Naturwissenschaften. Gegenstand dieser Doktorarbeit ist die raumzeitliche Dynamik räumlich-ausgedehnter, nichtlinearer Systeme mit Zeitverzögerung, mit besonderem Augenmerk auf deren lokalisierte Lösungen. Die betrachteten Systeme werden beschrieben durch partielle Differentialgleichungen und gekoppelte Systeme von gewöhnlichen Differentialgleichungen mit verzögerter Rückkopplung. Hinsichtlich der partiellen Differentialgleichungen untersucht diese Arbeit die Existenz und Stabilität der ebenen Wellenlösungen ebenso, wie die Existenz und Stabilität der lokalisierten Lösungen der eindimensionalen, komplexen, kubischen und kubisch-quintischen Ginzburg-Landau Gleichung mit verzögerter, optischer Rückkopplung. Das erste Ergebnis dieser Arbeit ist die vollständige Beschreibung der Menge der ebenen Wellenlösungen und ihre Stabilität für lange Verzögerungszeiten. Aufgrund der Symmetrie der Ginzburg-Landau Gleichung bildet diese Menge eine eindimensionale Familie, die zum Auftreten einer „Tube“ in Parameter-Koordinaten führt. Das zweite, neuartige Ergebnis ist die Beschreibung der Modulationsinstabilität dieser lokalisierten Strukturen. Diese Instabilität kann zu einer periodischen und chaotischen Zickzackbewegung der Lösung führen. Das dritte Resultat ist die Charakterisierung gebundener Impulsfolgen in einem System von gekoppelten gewöhnlichen Differentialgleichungen mit Zeitverzögerung, das zur Beschreibung einer Anordnung von modengekoppelten Lasers herangezogen wird. In diesem Regime interagieren die modengekoppelten Impulse in verschiedenen Lasern lokal über die Balance von Abstoßung und Anziehung. Resultierend daraus entstehen Cluster von Impulsen, die in einzelnen modengekoppelten Lasern nicht möglich sind. Sämtliche genannte Phänomene wurden analytisch und numerisch behandelt. / Systems with time-delay are ubiquitous in nature and attract significant interest in the field of nonlinear dynamics. The scope of this Thesis is the spatiotemporal dynamics in spatially extended nonlinear systems with time-delay, with a focus on the dynamics of localized structures. The systems under consideration are described by partial differential equations with delayed feedback and coupled systems of delay differential equations. For the partial differential equations, the existence and stability of plane wave solutions as well as localized structures are investigated in one-dimensional complex cubic and cubic-quintic Ginzburg-Landau equation with delayed feedback. The first result of this Thesis is the complete description of the set of plane wave solutions and their stability in the limit of large delay time. Due to the symmetry of Ginzburg-Landau equation, this set forms a one-dimensional family which leads to the appearance of the “tube” in parameter coordinates which is filled densely with plane wave solutions with the increase of the delay time. The second novel result is the description of modulational instability of localized structures in spatially extended systems with time-delay which can lead to periodic and chaotic zigzagging movement of the solution. The third result is the description of bound pulse trains in coupled delay systems depicting an array of mode-locked lasers. In this regime mode-locked pulses in different lasers interact locally via the balance of their repulsion and attraction. As a result, clusters of pulses emerge which can not exist in a solitary mode-locked laser. All of the aforementioned phenomena were described analytically and the results are supported by path continuation methods as well as direct numerical simulations with a specially designed software tool.

Le projet HODISS dans le cadre duquel s'effectue nos travaux adresse la problématique de la synchronisation globale des systèmes complexes sur puce (System-on-Chip ou SOCs, par exemple un multiprocesseur monolithique). Les approches classiques de distribution d'horloges étant devenues de plus en plus obsolètes à cause de l'augmentation de la fréquence d'horloge, l'accroissement des temps de propagation, l'accroissement de la complexité des circuits et les incertitudes de fabrication, les concepteurs s’intéressent (pour contourner ces difficultés) à d'autres techniques basées entre autres sur les oscillateurs distribués. La difficulté majeure de cette dernière approche réside dans la capacité d’assurer le synchronisme global du système. Nous proposons un système d'horlogerie distribuée basé sur un réseau d’oscillateurs couplés en phase. Pour synchroniser ces oscillateurs, chacun d'eux est en fait une boucle à verrouillage de phase qui permet ainsi d'assurer un couplage en phase avec les oscillateurs des zones voisines. Nous analysons la stabilité de l'état synchrone dans des réseaux cartésiens identiques de boucles à verrouillage de phase entièrement numériques (ADPLLs). Sous certaines conditions, on montre que l'ensemble du réseau peut synchroniser à la fois en phase et en fréquence. Un aspect majeur de cette étude réside dans le fait que, en l'absence d'une horloge de référence absolue, le filtre de boucle dans chaque ADPLL est piloté par les fronts montants irréguliers de l'oscillateur local et, par conséquent, n'est pas régi par les mêmes équations d'état selon que l'horloge locale est avancée ou retardée par rapport au signal considéré comme référence. Sous des hypothèses simples, ces réseaux d'ADPLLs dits "auto-échantillonnés" peuvent être décrits comme des systèmes linéaires par morceaux dont la stabilité est notoirement difficile à établir. L'une des principales contributions que nous présentons est la définition de règles de conception simples qui doivent être satisfaites sur les coefficients de chaque filtre de boucle afin d'obtenir une synchronisation dans un réseau cartésien de taille quelconque. Les simulations transitoires indiquent que cette condition nécessaire de synchronisation peut également être suffisante pour une classe particulière d'ADPLLs "auto-échantillonnés". / The HODISS project, context in which this work is achieved, addresses the problem of global synchronization of complex systems-on-chip (SOCs, such as a monolithic multiprocessor). Since the traditional approaches of clock distribution are less used due to the increase of the clock frequency, increased delay, increased circuit complexity and uncertainties of manufacture, designers are interested (to circumvent these difficulties) to other techniques based among others on distributed synchronous clocks. The main difficulty of this latter approach is the ability to ensure the overall system synchronization. We propose a clock distribution system based on a network of phase-coupled oscillators. To synchronize these oscillators, each is in fact a phase-locked loop which allows to ensure a phase coupling with the nearest neighboring oscillators. We analyze the stability of the synchronized state in Cartesian networks of identical all-digital phase-locked loops (ADPLLs). Under certain conditions, we show that the entire network may synchronize both in phase and frequency. A key aspect of this study lies in the fact that, in the absence of an absolute reference clock, the loop-filter in each ADPLL is operated on the irregular rising edges of the local oscillator and consequently, does not use the same operands depending on whether the local clock is leading or lagging with respect to the signal considered as reference. Under simple assumptions, these networks of so-called “self-sampled” all-digital phase-locked-loops (SS-ADPLLs) can be described as piecewise-linear systems, the stability of which is notoriously difficult to establish. One of the main contributions presented here is the definition of simple design rules that must be satisfied by the coefficients of each loop-filter in order to achieve synchronization in a Cartesian network of arbitrary size. Transient simulations indicate that this necessary synchronization condition may also be sufficient for a specific class of SS-ADPLLs.

La NADPH cytochrome P450 réductase (CPR) est une flavoprotéine multidomaines appartenant à la famille des diflavines réductases et un des composants essentiels du système redox des cytochromes P450. La CPR est formée de deux domaines catalytiques contenant des groupements prosthétiques FAD et FMN et d'un domaine de connexion. Le domaine FAD reçoit deux électrons du NADPH et les transfère un par un au domaine FMN, qui, à son tour, les transfère aux accepteurs. Le transfert d’électron du FMN vers les accepteurs nécessite un déplacement du domaine FMN par rapport au reste de la molécule. Au fils des années, les études structurales menées sur la CPR ont mis en évidence la réorganisation structurale et l’arrangement des domaines dans cette protéine. Cependant, les résultats de ces analyses ne fournissent pas d’informations concernant la vitesse à laquelle les mouvements des domaines de la CPR s’effectuent et n’incluent toujours pas les paramètres qui induisent le changement conformationnel ainsi que l'influence de ces changements sur l’activité catalytique de la CPR.Le projet de cette thèse a consisté à apporter de nouveaux éléments de compréhension sur la relation entre les changements conformationnels de la CPR et son cycle catalytique. La première partie de ce travail a porté sur le développement de stratégies de préparation au marquage des domaines catalytiques de la CPR, destinés à l’étude dynamique de cette protéine par le FRET. Différentes stratégies ont été envisagées parmi lesquelles l’incorporation de p-acétyle phénylalanine sur des positions définies dans la CPR. La deuxième partie de ce travail est consacrée à l’étude dynamique de la CPR via des techniques de RMN et SAXS combinées à des approches biochimiques. Les expériences menées ont permis de caractériser en solution et en absence de NaCl, la présence d’un état rigide, globulaire en conformation fermée dans laquelle les domaines FMN et FAD sont maintenus « verrouillés » par des interactions à l’interface entre ces deux domaines. L’augmentation de la concentration en NaCl permet une transition de cet état « verrouillé » vers un état plus ouvert pour lequel il n’y a plus d’interface entre les domaines FAD et FMN. L’état « déverrouillé » de la CPR correspond à un équilibre dynamique entre un ensemble de conformations en échange rapide. Cet équilibre est contrôlé par la force ionique et l’activité catalytique de la CPR est maximale lorsque les états verrouillés et déverrouillés sont également peuplés. Le modèle cinétique proposé par nos études a permis de mettre en évidence un lien direct entre la dynamique des domaines et l’activité du transfert d’électron au cours de cycle catalytique de la CPR. / NADPH cytochrome P450 reductase (CPR) is a multidomain flavoprotein that belongs to the diflavines reductase family. It is an essential component of redox system delivering electrons for cytochrome P450. CPR is composed of two catalytic domains containing FAD and FMN prosthetic groups and a connecting domain. FAD domain receives two electrons from NADPH and transfers them one by one to the FMN domain, which in turn transfers them to the acceptor. The electron transfer from FMN to the acceptor requires a large domain movement. Over the years, structural studies of CPR have highlighted the reorganization and arrangement of domains in this protein. However, the results of these analyses do not provide any information about how fast the domains movements takes place in CPR, and do not always include the parameters that induce conformational change as well as influence of those changes on the catalytic activity of the CPR. This thesis aims to bring new elements of comprehension on the relationship between conformational changes in CPR and its catalytic cycle. The first part of the work concerned the development of strategies to label the catalytic domains of CPR, a prerequisite for the dynamic study of this protein by FRET. Different strategies have been proposed including the incorporation of p-acetyl phenylalanine at defined positions in CPR. The second part of this work is devoted to the dynamic study of CPR through a combined SAXS, NMR and biochemical approaches. The experiments conducted allowed to characterize the presence of a rigid and globular state of closed conformation for CPR, in solution and in the absence of NaCl. In this conformation the FMN and FAD domains are kept "locked" by interface interactions between these two domains. Increasing the NaCl concentration permits the transition from the "locked" stats to an open conformation in which there is no more interface between the FAD and FMN domains. The "unlocked" state of CPR is a dynamic equilibrium between ensembles of conformations in fast exchange. This equilibrium is controlled by the ionic strength and CPR presents its maximum catalytic activity when the locked and unlocked states are equally populated. We proposed a kinetic model which allows demonstrating a direct link between the domain movement and electron transfer activity during the catalytic cycle of CPR.

This thesis is concerned with synthesis, structure and biochemical analysis of chemically modified oligonucleotides with potential therapeutic applications. The three types of chemical modifications described here are: (a) A North-East locked 1',2'-azetidine nucleoside (b) A North locked 2',4'-cyanomethylene bridged nucleoside and (c) A 2',4'-aza-ENA-T nucleoside. The synthesis of the 1',2'-azetidine fused nucleosides was described using two different approaches. A highly strained 2',4'-cyanomethylene locked nucleoside was synthesized but could not be converted to the phosphoramidite derivative due to instability during derivatization. The key cyclization step in the aza-ENA-T nucleoside synthesis gave rise to two separable diastereomers due to chirality at the exocyclic nitrogen. Conversion of diastereomer 55 to 56 occurred with a large free energy of activation (ΔG‡ = 23.4 kcal mol-1 at 298 K in pyridine-d5). Of the two isomers the equatorial NH product was more stable than the axial one due to reduced 1,3 diaxial interactions. As a result, all NH axial product was converted to the equatorial isomer during subsequent steps in the synthesis. NMR and ab initio experiments confirmed the North-East structure of the 1',2'-azetidine locked nucleoside and North conformation of aza-ENA-T locked nucleosides with a chair conformation of the piperidine ring. The amino modified nucleosides were incorporated into different positions of a 15mer oligonucleotide. The azetidine modified AONs did not form stable duplexes with complementary RNA (ΔTm ~-1 to -4 °C), but they performed better than previously synthesized isosequential 1',2'-oxetane modified oligonucleotides. The 2',4'-aza-ENA-T modified oligonucleotide, on the other hand, showed excellent target affinity with complementary RNA (ΔTm ~+4 °C). The azetidine and aza-ENA-T modified oligonucleotides showed significant stability in the presence of human serum and snake venom phosphodiesterase (3'-exonuclease) as compared to the unmodified native sequence. The singly modified 15mer oligonucleotides were also subjected to RNase H promoted digestion in order to evaluate their potential as effective antisense agents. The effective enzyme activity (kcat/Km) was found to be lower in the modified AONs due to reduced enzyme-substrate binding. However, the catalytic activity of RNase H with these modified-AON:RNA duplexes were higher than observed with the native duplex.

Ultra narrow-band filters and the use of two loops in a cascade configuration dominate current clock conditioners based on phase-locked-loop (PLL) schemes. Since a PLL exhibits a low-pass transfer function with respect to the reference clock, the noise performance at very close-to-carrier offset frequencies is still determined by the input signal. Although better cleaning can be achieved with extremely narrow loops, an ultra low cut-off frequency could not be selected since the stability of the configuration deteriorates as the filter bandwidth is reduced. This fact suggests that a full-spectrum clock conditioning is not possible using traditional PLL architectures, and an alternative scheme is necessary to attenuate the very-close-to-carrier phase noise (PN). In addition, ultra-narrow loop filters can compromise on-chip integration because of the large size capacitors needed when chosen as passive. Input signal attenuation with relaxed bandwidth requirements becomes the main aspect that a comprehensive clock cleaner must address to effectively regenerate a reference signal. This dissertation describes the Band-Reject Nested-PLL (BRN-PLL) scheme, a modified PLL-based architecture that provides an effective signal cleaning procedure by introducing a notch in the input transfer function through inner and outer loops and a high-pass filter (HPF). This modified response attenuates the reference-signal PN and reduces the size of the loop-filter capacitors substantially. Ultra narrow loops are no longer required because the notch size is related to the system bandwidth. The associated transfer function for the constitutive blocks (phase detectors and local oscillators) show that the output close-to-carrier and far-from-carrier PN sections are mainly dominated by the noise from the inner-PLL phase detector (PD) and local oscillator (LO) located in the outer loop, respectively. The inner-PLL PD transfer function maintains a low-pass characteristic with a passband gain inversely proportional to the PD gain becoming the main contribution around the carrier signal. On the other hand, the PN around the transition frequency is determined mainly by the reference and the inner-PLL LO. Their noise contributions to the output will depend on the associated passband local maxima, which is located at the BRN-PLL transition frequency. Hence, in this region, the inner-PLL LO is selected so that its effect can be held below that of the outer-PLL PD. The BRN-PLL can use a high-Q MEMS-based VCO to further improve the transition region of the output PN profile and an LC-VCO as outer-PLL LO to reduce the noise floor of the output signal. In particular, two tuning mechanisms are explored for the MEMS-VCO: series tuning using varactors and phase shifting of a resonator operating in nonlinear regime. Both schemes are implemented to generate a tunable oscillator with no PN-performance degradation.

Die Spezifikationen und Toleranzbereiche heutiger Hochgeschwindigkeitsdatenübertragungstechnologien nehmen immer weiter an Komplexität, aufgrund der steigenden Informationsmenge, zu. Zur Verarbeitung von Daten in Frequenzbereichen oberhalb von einem Gigahertz sind Referenzsignale notwendig, welche ein äußerst geringes Phasenrauschen aufweisen um benachbarte Kanäle nicht zu beeinflussen. Diese Referenzsignale werden in Mischerschaltungen zur Modulation oder Demodulation zwischen radio frequency (RF)- und intermediate frequency (IF)-Signalen verwendet. Die benötigte Signalform ist eine Sinusschwingung, die nicht durch digitale Schaltungsblöcke erzeugt werden kann. Daher ist die Notwendigkeit von analogen LC-Oszillatoren gegeben. Die Erzeugung von höchst stabilen und hochfrequenten Signalen war lange Zeit teuren Silizium-Germanium-Technologien vorbehalten. Jedoch erfordert der steigende Integrationsgrad und der hart umkämpfte Markt, die Entwicklung von RF-Schaltungen in günstigen CMOS-Technologien. In Zusammenarbeit mit der Landshut Silicon Foundry soll dazu eine monolithisch integrierte Phase-Locked Loop (PLL) mit einer mittleren Ausgangsfrequenz von 2,44 GHz und einem Phasenrauschen kleiner -115 dBc/Hz bei einem Abstand von 1 MHz vom Träger entwickelt werden. Dabei wird das Hauptaugenmerk auf den Kern der PLL gelegt, welcher einen spannungsgesteuerten Oszillator, einen Phasen-/Frequenzdetektor, eine Ladungspumpe, einen Schleifenfilter und einen Frequenzteiler beinhaltet. Außerdem sollen Testszenarien vorgestellt werden, um die Eigenschaften der gefertigten PLL zu bestimmen und zu vergleichen.

No description available.