<p>This thesis is one part of a overall task of designing a module for frequency shift keying (FSK) to be used in an Ultra Wide Band (UWB) system. The FSK system has a Direct Digital Synthesizer (DDS) and Digital-to-Analog (DAC). The DACs differential current signals are directly fed to a RF (Radio Frequency) unit that generates the UWB RF signal.</p><p>The focus of this thesis is on DAC while the DDS is developed in VHDL as another thesis work. This thesis demonstrates a low-power, ultra wide band 10 bit DAC with an update frequency of 24 MSPS(Mega Samples Per Second). The DAC uses a L-fold linear interpolation architecture. It includes a 16-tap voltage controlled delay line and a 10 bit binary-weighted DAC with a time interleaved structure. The linear interpolation technique improves the attenuation of mirror components and also reduces the glitch. This helps to relax the analog filter requirements and sometimes an off chip capacitor is enough as low pass filter. The attenuation of image components is doubled in decibels(dB) compared with that of conventional DAC.</p><p>In this work various DAC architectures are studied. The current-steering DAC is chosen due to its high speed and high resolution. A binary weighted architecture is chosen to reduce the digital circuits. This helped in reducing the power consumption. The design and simulation is done with help of Cadence. The layout is done in Cadence Virtuoso and the DDS is integrated with the DAC. The chip is to be manufactured in 130 nm CMOS process.</p>

The work was based on digitally controlled oscillator for an all-digital PLL in 65nm process. Phase locked loop’s were used in most of the application for clock generation and recovery as well. As the technology grows faster in the existinggeneration, there has to be quick development with the technique. In such case ananalog PLL which was used earlier gradually getting converted to digital circuit.All-digital PLL blocks does the same work as an analog PLL blocks, but thecircuits and other control circuitry designed were completely in digital form, becausedigital circuit has many advantages over analog counterpart when they arecompared with each other. Digital circuit could be scaled down or scaled up evenafter the circuits were designed. It could be designed for low power supply voltageand easy to construct in a 65 nm process. The digital circuit was widely chosento make life easier. In most of the application PLL’s were used for clock and data recovery purpose,from that perspective jitter will stand as a huge problem for the designers. Themain aim of this thesis was to design a DCO that should bring down the jitter asdown as possible which was designed as standalone, the designed DCO would belater placed in an all-digital PLL. To understand the concept and problem aboutjitter at the early stage of the project, an analog PLL was designed in block leveland tested for different types of jitter and then design of a DCO was started. This document was about the design of a digitally controlled oscillator whichoperates with the center frequency of 2.145 GHz. In the first stage of the projectthe LC tank with NMOS structure was built and tested. In the latter stage the LCtank was optimized by using PMOS structure as negative resistance and eventuallyended up with NMOS and PMOS cross coupled structure. Tuning banks were oneof the main design in this project which plays a key role in locking the system ifthe DCO is placed in an all-digital PLL system. So, three types of tuning bankswere introduced to make the system lock more precisely. The control circuits andthe varactors built were all digital and hence it is called as digitally controlledoscillator. Digital control circuits, other sub-blocks like differential to single endedand simple buffers were also designed to optimize the signal and the results wereshown.DCO and tuning banks were tested using different types of simulation and were tested for different jitter qualities and analysis. The simulation results are shownin the final chapter simulation and results.

This thesis is one part of a overall task of designing a module for frequency shift keying (FSK) to be used in an Ultra Wide Band (UWB) system. The FSK system has a Direct Digital Synthesizer (DDS) and Digital-to-Analog (DAC). The DACs differential current signals are directly fed to a RF (Radio Frequency) unit that generates the UWB RF signal. The focus of this thesis is on DAC while the DDS is developed in VHDL as another thesis work. This thesis demonstrates a low-power, ultra wide band 10 bit DAC with an update frequency of 24 MSPS(Mega Samples Per Second). The DAC uses a L-fold linear interpolation architecture. It includes a 16-tap voltage controlled delay line and a 10 bit binary-weighted DAC with a time interleaved structure. The linear interpolation technique improves the attenuation of mirror components and also reduces the glitch. This helps to relax the analog filter requirements and sometimes an off chip capacitor is enough as low pass filter. The attenuation of image components is doubled in decibels(dB) compared with that of conventional DAC. In this work various DAC architectures are studied. The current-steering DAC is chosen due to its high speed and high resolution. A binary weighted architecture is chosen to reduce the digital circuits. This helped in reducing the power consumption. The design and simulation is done with help of Cadence. The layout is done in Cadence Virtuoso and the DDS is integrated with the DAC. The chip is to be manufactured in 130 nm CMOS process.

> Ce manuscrit présente une étude théorique et expérimentale effectuée sur des transistors MOSFET d'une> technologie avancée de type FD SOI (complètement déserté silicium sur isolant). Des mesures électriques> combinées avec des modélisations ont été effectuées dans le but d'apporter des explications sur des phénomènes> liés à réductions des dimensions des transistors. Ce travail de thèse donne une réponse partielle de l'impact de ces> aspects sur les paramètres électrique ainsi que les paramètres de transport."

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-10-16T20:00:15Z No. of bitstreams: 1 GLEUSON LIMA MARANHÃO – DISSERTAÇÃO (PPGFísica) 2016.pdf: 2014401 bytes, checksum: bfec9d592ed3c9e262372aea5abdf23c (MD5) / Made available in DSpace on 2018-10-16T20:00:15Z (GMT). No. of bitstreams: 1 GLEUSON LIMA MARANHÃO – DISSERTAÇÃO (PPGFísica) 2016.pdf: 2014401 bytes, checksum: bfec9d592ed3c9e262372aea5abdf23c (MD5) Previous issue date: 2016-02 / Capes / Este trabalho analisa os parâmetros horizontais observados e intrínsecos (período, comprimentos de onda e velocidade de fase) de ondas de gravidade periódicas detectadas na emissão do OI630 nm da aeroluminescência noturna. As observações foram realizadas em São João do Cariri (coordenadas geográfi cas: 7:4 S; 36:5 W, coordenadas geomagnéticas: 0:480 N; 35:8 E). Foram observadas 51 ondas de gravidade entre setembro de 2011 e abril de 2015 utilizando um imageador de aeroluminescência. Foi possível estudar os parâmetros de 31 delas utilizando o método de análise espectral. As características espectrais dessas ondas se assemelharam com observações feitas em outras localidades, i.e., os períodos observados caíram bem distribuídos entre 12 e 30 min, os comprimentos de onda horizontais entre 90 e 180 km e as velocidades de fase observadas entre 30 e 180 m/s. A maioria das ondas observadas apresentou direção de propagação para leste e nordeste. Medidas simultâneas de vento termosférico feitas por dois interferômetros Fabry-Perot, instalados em São João do Cariri e Cajazeiras (coordenadas geográfi cas: 6:9 S; 38:5 W, coordenadas geomagnéticas: 01:49 N; 33:4 E), também foram utilizadas para estimar os parâmetros intrínsecos das ondas de gravidade. O vento termosférico apresentou direção de escoamento predominantemente para sudeste. Os períodos observados das ondas de gravidade apresentaram mudanças, principalmente, entre 18 e 30 min comparados com os períodos intrínsecos. Todas as ondas com direção de propagação para norte e noroeste apresentaram redução na velocidade de fase horizontal observada quando comparadas com a velocidade de fase intrínseca. Da mesma forma, a maior parte das ondas com direção de propagação para nordeste apresentou redução na velocidade de fase observada. Por outro lado, a maioria das ondas com direção de propagação para sudeste apresentou aumento na velocidade de fase observada. Já para as ondas propagantes para leste, todas apresentaram aumento na velocidade de fase observada. / In this work, observed and intrinsic parameters(period, wavelength and phase speed) of gravity waves were studied using OI 630.0 nm airglow measurements. Those waves were observed at São João do Cariri (geographic coordinates: 7:4 S; 36:5 W, geomagnetic coordinates: 0:48 N, 35:8 L). A total of 51 gravity waves events were observed from September 2011 to April 2015 using an all sky airglow imager. Intrinsic parameters of 31 gravity waves were estimated using spectral analysis. The spectral characteristics of the waves are in agreement with observations made in other places around the world, i.e., the observed periods range between 12 and 30 minutes, the horizontal wavelengths from 90 to 180 km and the observed phase speed were from 30 to 180 m/s. Most of the observed waves showed the propagation direction to the east and northeast. Simultaneous measurements of the atmospheric wind made by two Fabry-Perot Interferometers, deployed at São João do Cariri and Cajazeiras ( geographic coordinates: 6:9 S; 38:5 W, geomagnetic coordinates: 01:49 N; 33:41 L), were also used to estimate the intrinsic parameters of the gravity waves. The termospheric wind blows predominantly to the southwest. The observed periods of the gravity waves showed changes, mainly between 18 and 30 min as compared to the intrinsic ones. All of the waves that had propagation direction to the north and northwest decreased their horizontal observed phase speed when they are compared to the intrinsic phase speed. Furthermore, most of the waves propagating to the northeast decreased their observed phase speed.On the other hand, most of the waves propagating to the southeast increased the observed phase speed.Thus, all of the waves propagating eastward had the observed phase speed increased.

Background This thesis explores the role of ethics in negotiations within the international defence industry. Existing gaps in literature are identified by using two existing literature reviews: one concerning negotiations and one concerning ethics. The gaps in existing literature lead to the need for a number of areas of development: the need for new negotiation models; the need to include ethics in international negotiations; and the need for studies to included negotiation professionals, opposed to students. Methodology and Method The method used consists of a single-case study using interviews to gain insight from those responsible for negotiations and ethics at Saab, a Swedish International defence company. Theoretical Framework To explore the possibilities of an ethically based negotiation model, two existing models were examined. The first used is the Value-Based Negotiation Model (VBN) by Gan (2017) and establishes a negotiation framework. The second model by Erwin (2010) offers perspectives on the effectiveness of documents used to establish ethical foundations in organizations. Proposed Research Framework The research framework that is established is the Sanfran Ethical International Business Negotiations Model. The model incorporates the steps needed for successful integrative negotiations with aspects aimed at increasing ethical collaboration and to reduce the risk of unethical behaviour. Findings and further research. The research has fulfilled its two goals by adding to existing literature surrounding negotiations and by developing a conceptual framework to be used in international defence negotiations that uses ethical requirements as a foundation. Implications for theory and practice are discussed and future research directions are offered.

L'objectif principal de cette thèse est de proposer et d'évaluer une nouvelle architecture de Transistor Bipolaire à Héterojonction (TBH) Si/SiGe s’affranchissant des limitations de l'architecture conventionnelle DPSA-SEG (Double-Polysilicium Self-Aligned, Selective Epitaxial Growth) utilisée dans la technologie 55 nm Si/SiGe BiCMOS (BiCMOS055) de STMicroelectronics. Cette nouvelle architecture est conçue pour être compatible avec la technologie 28-nm FD-SOI (Fully Depleted Si-licon On Insulator), avec pour objectif d'atteindre la performance de 400 GHz de fT et 600 GHz de fMAX dans ce noeud. Pour atteindre cet objectif ambitieux, plusieurs études complémentaires ont été menées: 1/ l'exploration et la comparaison de différentes architectures de TBH SiGe, 2/ l'étalonnage TCAD en BiCMOS055, 3/ l'étude du budget thermique induit par la fabrication des technologies BiCMOS, et finalement 4/ l'étude d'une architecture innovante et son optimisation. Les procédés de fabrication ainsi que les modèles physiques (comprenant le rétrécissement de la bande interdite, la vitesse de saturation, la mobilité à fort champ, la recombinaison SRH, l'ionisation par impact, la résistance distribuée de l'émetteur, l'auto-échauffement ainsi que l’effet tunnel induit par piégeage des électrons), ont été étalonnés dans la technologie BiCMOS055. L'étude de l’impact du budget thermique sur les performances des TBH SiGe dans des noeuds CMOS avancés (jusqu’au 14 nm) montre que le fT maximum peut atteindre 370 GHz dans une prochaine génération où les profils verticaux du BiCMOS055 seraient ‘simplement’ adaptés à l’optimisation du budget thermique total. Enfin, l'architecture TBH SiGe EXBIC, prenant son nom d’une base extrinsèque épitaxiale isolée du collecteur, est choisie comme la candidate la plus prometteuse pour la prochaine génération de TBH dans une technologie BiCMOS FD-SOI dans un noeud 28 nm. L'optimisation en TCAD de cette architecture résulte en des performances électriques remarquables telles que 470 GHz fT et 870 GHz fMAX dans ce noeud technologique. / The ultimate objective of this thesis is to propose and evaluate a novel SiGe HBT architec-ture overcoming the limitation of the conventional Double-Polysilicon Self-Aligned (DPSA) archi-tecture using Selective Epitaxial Growth (SEG). This architecture is designed to be compatible with the 28-nm Fully Depleted (FD) Silicon On Insulator (SOI) CMOS with a purpose to reach the objec-tive of 400 GHz fT and 600 GHz fMAX performance in this node. In order to achieve this ambitious objective, several studies, including the exploration and comparison of different SiGe HBT architec-tures, 55-nm Si/SiGe BiCMOS TCAD calibration, Si/SiGe BiCMOS thermal budget study, investi-gating a novel architecture and its optimization, have been carried out. Both, the fabrication process and physical device models (incl. band gap narrowing, saturation velocity, high-field mobility, SRH recombination, impact ionization, distributed emitter resistance, self-heating and trap-assisted tunnel-ing, as well as band-to-band tunneling), have been calibrated in the 55-nm Si/SiGe BiCMOS tech-nology. Furthermore, investigations done on process thermal budget reduction show that a 370 GHz fT SiGe HBT can be achieved in 55nm assuming the modification of few process steps and the tuning of the bipolar vertical profile. Finally, the Fully Self-Aligned (FSA) SiGe HBT architecture using Selective Epitaxial Growth (SEG) and featuring an Epitaxial eXtrinsic Base Isolated from the Collector (EXBIC) is chosen as the most promising candidate for the 28-nm FD-SOI BiCMOS genera-tion. The optimization of this architecture results in interesting electrical performances such as 470 GHz fT and 870 GHz fMAX in this technology node.

The diploma thesis is focused on preference learning. Preferences can be analyzed in many areas starting from economics, over the statistics to informatics. This thesis is focused on informatics point of view on preferences. At the beginning it is focusing on preferences in general and analyzing its origin in economical science. Then this knowledge base is used for analysis of informatics methods employed in preference learning which also includes machine learning and describes how these sciences are connected with each other. Practical part of work is focused on employing informatics preferences in practice. The basic tasks and methods are described at the beginning and followed by more detailed analysis of one the methods (UTA NM). The result consists of description and implementation of a REST web service that can be used for one of the preference learning tasks.

In this master thesis project, a pulsed UV laser was designed and constructed. Also, the effects of absorption in a volume Bragg grating were investigated. The laser was diode pumped and constructed with Yb:KYW as gain medium. The lasing was at a wavelength of 1029.2 nm with a spectral bandwidth of 0.23 nm, locked by a volume Bragg grating that was used as input coupler for spectral control. Passive Q‑switching was used to generate pulses by placing a Cr:YAG saturable absorber inside the cavity. The laser generated radiation with a maximum peak power of 3.8 kW at an average power of 0.35 W, a repetition rate of 4 kHz and a pulse width of 16 ns. The maximum average power was 1.3 W with a peak power of 2 kW at a repetition rate of 20 kHz and with a pulse width of 20 ns. Through extra‑cavity second harmonic generation using an LBO crystal, green light at a wavelength of 514.7 nm was generated. The maximum average power was 130 mW with an optical conversion efficiency from the fundamental of around 10 %. Then, the second harmonic and the fundamental wave were mixed to generate UV light, at a wavelength of about 343 nm, by using a second LBO crystal. The maximum average power of UV was about 23 mW with an optical efficiency, with respect to the green, of approximately 20 %. One limitation of the laser was that the Cr:YAG was bleached not only by the circulating laser field, but also by remaining pump light. This resulted in decreasing peak power with increasing pump power, thus limiting the nonlinear conversion efficiencies. Thermal fracture of the Cr:YAG was a limiting factor for the intra-cavity average power, while burning of the coating on the Yb:KYW crystal limited the maximum peak power. The effects on a laser when using too high power for the level of absorption in a volume Bragg grating were also investigated. The effects of both resonant and non-resonant beams were investigated.  Since the intensity of a resonant beam decreases approximately exponentially in a volume Bragg grating, due to absorption, an uneven temperature distribution along the propagation axis is formed. This results in different thermal expansion and hence, results in a longitudinal chirp of the grating. The chirp caused a decrease in both reflectivity and spectral selectivity. The reflectivity of the particular grating used in these experiments decreased from 99.4 % to 93 %. In addition, it was experimentally shown that if a volume Bragg grating absorbs a non-negligible amount of a non-resonant beam, the thermal load will deform the volume Bragg grating. Therefore, it is not suitable to use such a grating the as input coupler of a laser cavity. / I detta examensarbete utformades och konstruerades en pulsad UV-laser. Dessutom undersöktes effekterna av absorption i ett volymbraggitter. Som laserkristall användes Yb:KYW vilken pumpades med en diodlaser. Lasring skedde vid 1029,2 nm med en bandbredd av 0,23 nm genom att ett volymbraggitter användes som inkopplingsspegel för att kontrollera spectrumet. Pulser generades genom passiv Q-switching med en Cr:YAG som mättnadsbar absorbator inne i kaviteten. Den maximala toppeffekten var 3,8 kW vid 0.35 W medeleffekt, 4 kHz repetitionsfrekvens och en pulsbredd på 16 ns. Den maximala medeleffekten var 1.3 W med en toppeffekt på 3,8 kW, 20 kHz repetitionsfrekvens och en pulsbredd på 20 ns. Genom frekvensdubbling i en LBO kristall genererades grönt ljus vid våglängden 514,7 nm. Den maximala medeleffekten var 130 mW med en optisk verkningsgrad från den fundamentala våglängden på 10 %. Sedan blandades det infraröda och det gröna ljuset i en andra LBO kristall för att generera UV-ljus, vid en våglängd om 343 nm. Den högsta medeleffekten av UV var cirka 23 mW med en optisk verkningsgrad, med avseende på det gröna ljuset, på ungefär 20%. En begränsning av laser var att Cr:YAG kristallen blektes inte enbart av lasern utan även av pumpen. Detta resulterade i fallande toppeffekt med ökande pumpeffekt, vilket begränsade effektiviteten i den ickelinjära konverteringen. Termisk fraktur på Cr:YAG kristallen var en begränsande faktor för cirkulerande medeleffekten i kaviteten, medan brännskador på Yb-kristallens antireflexbehandling begränsade toppeffekten. Effekterna i en laser vid användning av en alltför hög effekt i förhållande till nivån av absorption i ett volymbraggitter studerades också. Effekterna av både resonanta och ickeresonanta strålar undersöktes. Eftersom intensiteten av en resonant ståle minskar ungefär exponentiellt i ett volymbraggitter kommer temperaturen, på grund av absorption, fördelas ojämnt i propageringsriktningen. Detta resulterar i olika termiska expansion med en längsgående varierad gitterperiod som följd. Detta orsakar en minskning utav både reflektiviteten och den spektrala selektiviteten. Reflektiviteten i gittret som användes i dessa experiment minskade från 99,4 % till 93 %. Dessutom visades det experimentellt att om ett volymbraggitter absorberar en icke försumbar del av en ickeresonant stråle kommer värmebelastning att deformera volymenbraggittret. Därför är det inte lämpligt att använda ett sådant gitter som inkopplingsspegel i en laser.

In this work, a coordinate wise descent algorithm is implemented which serves the purpose of estimating active users in a base station/client wireless communication setup. The implemented algorithm utilizes the sporadic nature of users, which is believed to be the norm with 5G Massive MIMO and Internet of Things, meaning that only a subset of all users are active simultaneously at any given time. This work attempts to estimate the viability of a direct algorithm implementation to test if the performance requirements can be satisfied or if a more sophisticated implementation, such as a parallelized version, needs to be created.The result is an isomorphic ASIC implementation made in a 28 nm FD-SOI process, with proper internal word lengths extracted through simulation. Some techniques to lessen the burden on hardware without losing performance is presented which helps reduce area and increase speed of the implementation. Finally, a parallelized version of the algorithm is proposed, if one should desire to explore an implementation with higher system throughput, at almost no furtherexpense of user estimation error.