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Využití oxidu yttria pro vytváření antireflexních vrstev solárních článků / Yttrium oxide layers for antireflection coating of silicon solar cellsDostál, Vladimír January 2010 (has links)
This work deals with deposition of yttrium oxide layers on silicon substrate (P – type) by using magnetron and reactive magnetron sputtering. Experiments which were made are further described. After that, work is focused on evaluation of deposited layers by using FTIR measurement technique and spectrophotometry. At the end of the work results of experiments are discussed also with the future progress.
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Miniaturizace a zvýšení dosahu modulu W-DMX v1.0 / Miniaturization and Range Extension of W-DMX v1.0 ModuleRojček, Martin January 2010 (has links)
The aim of this master thesis is to design a wireless system which would be primarily used for a control of stage lighting. Our idea is to establish wireless links, that will carry DMX512 protocol, between individual lighting devices based on wireless transceiver nRF2401A. The foundation of our project comes from a previous design, which was not completely suitable for a practical use because of its rather large proportions and a short RF range. The project resolves the issue of relatively short range coverage through the deployment of RF amplifier RF5722. In the same tme, it also takes into account other technical aspects such as the use of antenas with a higher gain, front-end circuits or increased transmission reliability through frequency hopping scheme. Proper attention is also given to a minimalization of the module dimensions by using SMD components and layout adjustements, so it would be possible to place the whole board inside XLR connector. Set of printed circuit boards with the specified characteristics, which is the expected outcome of our project, were designed with Eagle PCB design environment.
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Určování pozice senzorového uzlu mobilním systémem / Alocation of Sensor Node Position by a Mobile SystemHyrák, Jakub January 2016 (has links)
The goal of this diploma work is to study the problems of wireless sensor networks. Describe elements of sensor network and discuss how the individual sensor nodes communicate with each other. Find the way how it would be possible to determine the possition of the new added sensor node or mobile sensor node in the sensor network. The selected one algorithm of determining the possition of the sensor node will be implemented in diploma thesis. Algorithms for determining the positions of sensor nodes are divided into groups by using the methods. Selected algorithm will be tested in simulation on chosen platform.
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Circuit-tunable subwavelength terahertz devices / Dispositifs terahertz sub-longueur d'onde accordables par des composants discretsPaulillo, Bruno 21 June 2016 (has links)
La demande croissante en composants optoélectroniques de taille réduite, rapides, de faible puissance et à faible coût oriente la recherche vers des sources et détecteurs de radiation ayant une dimension inférieure à la longueur d'onde émise/détectée. Cette dernière est entravée par la limite de diffraction qui fixe la dimension minimale des dispositifs optiques à la moitié de la longueur d'onde de fonctionnement. A l'inverse, les dispositifs électroniques, tels que les antennes et les oscillateurs, ne sont pas limitée en taille et leur fréquence peut être accordée par des composants discrets. Par conséquent, unifier les mondes de la photonique et de l'électronique permettrait de concevoir de nouveaux dispositifs optoélectroniques sans limitation de taille imposée par la longueur d'onde et ayant des fonctionnalités empruntées aux circuits électroniques. La région spectrale idéale pour développer ce paradigme est la gamme térahertz (THz), à mi-chemin entre les domaines de l'électronique et de l'optique. Dans la première partie de ces travaux, nous présentons de nouveaux micro-résonateurs sub-longueur d’onde en 3D qui fonctionnent comme des circuits LC microscopiques et où la fréquence de résonance peut être accordée en agissant séparément sur la région capacitive et/ou inductive. Dans la deuxième partie, nous illustrons la puissance de cette approche en réalisant de nouveaux méta-dispositifs THz passifs (polaritoniques, commutables optiquement, optiquement actifs) basés sur des composants discrets. La dernière partie de cette thèse est consacrée aux méta-dispositifs actifs. Des photodétecteurs THz à puits quantiques ayant une dimension ≈λ eff /10, en configuration objet unique et réseau sont démontrées, grâce à un schéma de contact efficace et originale pour extraire (injecter) un courant depuis (dans) le cœur semi-conducteur intégré dans chaque résonateur. Enfin, une étude de faisabilité d'un laser sub-longueur d’onde aux fréquences THz est présentée. / The need for small, fast, low-power and low-cost optoelectronic components is driving the research towards radiation sources and detectors having a dimension that is smaller than the emitted/detected wavelength. This is hampered by the optical diffraction limit which constrains the minimum dimension of optical devices at half the operating wavelength. Conversely, electronic devices, such as antennas and oscillating circuits, are not diffraction-limited in size and can be frequency tuned with lumped components. Hence, blending the worlds of photonics and electronics has the potential to enable novel optoelectronic devices with no lower size limit imposed by the wavelength, and with novel functionalities borrowed from electronic circuits. The ideal spectral region to develop this paradigm is the terahertz (THz) range, halfway between the electronics and optics realms. In the first part of this work, we present novel subwavelength 3D micro-resonators that behave as microscopic LC circuits, where the resonant frequency can be tuned acting separately on the capacitive and/or inductive regions. In the second part we illustrate the power of this concept by implementing novel lumped-elements-based passive THz meta-devices (polaritonic, optically switchable, optically active). The last part of this thesis is devoted to active meta-devices. Single-pixel and arrays of THz quantum well photodetectors featuring a ≈λeff/10 dimension are demonstrated, thanks also to an effective and original contact scheme to extract (inject) current from (into) the semiconductor core embedded by each resonator. Finally, a feasibility study of a subwavelength laser at THz frequencies is reported.
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Nova konfiguracija širokopojasnog nisko-šumnog pojačavača u CMOS tehnologiji / А new design of ultra-wideband low noise amplifier in CMOS technologyĐugova Alena 27 June 2016 (has links)
<p>Nisko-šumni pojačavač (NŠP) nalazi se u prijemnom delu bežičnog<br />primopredajnika neposredno nakon antene. NJegova uloga je da ulazni<br />signal određene frekvencije i male snage izdvoji i pojača iznad nivoa<br />šuma prijemnika. U okviru doktorske disertacije prikazane su i<br />opisane metode za projektovanje širokopojasnih (UWB) NŠP u CMOS<br />tehnologiji. Ukupno je predloženo devet novih konfiguracija NŠP. Na<br />osnovu dobijenih rezultata, u 0,18 μm UMC CMOS tehnologiji<br />realizovan je i fabrikovan NŠP jednostavne topologije, koja<br />predstavlja zbir dva pristupa, pojačavačkog stepena kaskodne<br />strukture sa povratnom spregom i stepena sa višestrukim<br />iskorišćenjem struje. NŠP je projektovan za frekvencijski opseg od<br />3,1 do 5 GHz. Takođe, opisana je metoda za merenje parametara NŠP, a<br />zatim je i izvršena njegova karakterizacija.</p> / <p>In the transceiver chain the low noise amplifier (LNA) is placed in the frontend<br />of the receiver after the antenna. The LNA needs to isolate and amplify<br />received weak signal at a specific frequency above the noise level of the<br />receiver. In the scope of this doctoral dissertation methods for designing<br />ultra-wideband (UWB) LNA in CMOS technology are presented and<br />described. Nine new LNA configurations were proposed. Based on the<br />obtained results, simple LNA configuration, obtained by merging casode<br />feedback topology and current-reuse technique, was realized and fabricated<br />in 0.18 μm UMC CMOS technology. The LNA is designed for the frequency<br />band from 3.1 to 5 GHz. In addition, the method for measurement LNA<br />parameters is described and the proposed LNA was characterized.</p>
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Příprava a základní vlastnosti nanostrukturovaných plazmových polymerů / Preparation and basic properties of nanostructured plasma polymersSerov, Anton January 2014 (has links)
Smooth fluorocarbon plasma polymer films have been for a long time considered for fabrication of hydrophobic and slippery coatings. Interest in fluorocarbon materials was also supported by their excellent self-lubricant, dielectric properties and chemical inertness. This thesis is focused on development of new methods for fabrication of fluorocarbon plasma polymes, which could combine the chemical composition and the physical structure necessary for reaching superhydrophobic character of coatings. Poly(tetrafluoroethylene) was the subject material. RF magnetron sputtering using gas aggregation cluster source was the method adapted to fabricate fluorocarbon nanostructured films with chemical composition close to conventional bulk PTFE, but with high degree of cross- linking and branched structure. A model of growth of such plasma polymer nanostructures was discussed.
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Impact of BTI Stress on RF Small Signal Parameters of FDSOI MOSFETsChohan, Talha, Slesazeck, Stefan, Trommer, Jens, Krause, Gernot, Bossu, Germain, Lehmann, Steffen, Mikolajick, Thomas 22 June 2022 (has links)
The growing interest in high speed and RF technologies assert for the importance of reliability characterization beyond the conventional DC methodology. In this work, the influence of bias temperature instability (BTI) stress on RF small signal parameters is shown. The correlation between degradation of DC and RF parameters is established which enables the empirical modelling of stress induced changes. Furthermore, S-Parameters characterization is demonstrated as the tool to qualitatively distinguish between HCI and BTI degradation mechanisms with the help of extracted small signal gate capacitances.
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Det allmännas ansvar vid överträdelser av 1 kap. regeringsformen : Ett offentligrättsligt perspektiv på grundlagsöverträdelser / Public liability in violations of Chapter 1 of the Instrument of Government : A public law perspective on constitutional violationsTåhlin, Philip January 2022 (has links)
Public liability regarding violations of the European Convention on HumanRights (ECHR) in Sweden is a given fact; member states, including Sweden, responsiblefor such violations are liable to compensate the individuals whoserights have been violated. Since 2014, a right to compensation for certain stateviolations of the second chapter – the human rights chapter – in the Instrumentof Government (1974:152), one of Sweden’s constitutional laws, has been establishedin case law. In 2020, a Swedish Government Official Report was published,which examined whether a basis for compensation should be establishedin the Tort Liability Act (1972:207) for violations in general of the second chapterof the Instrument of Government. The parliamentary committee investigatingthe matter concluded that such a basis should be established as it wouldstrengthen legal certainty and increase the state’s accountability for violations ofhuman rights stated within the constitution. However, as the inquiry was limitedto the second chapter of the Instrument of Government, the question of thestate’s liability concerning violations of other chapters in the Instrument of Governmentremains unanswered.This thesis examines the state’s liability in violations of certain articles in thefirst chapter of the Instrument of Government from a public law perspective,using a legal doctrinal method. Accountability in this thesis is not limited to tortsand therefore include other ways to attain non-pecuniary reparation, as torts isthe last resort for individuals in terms of effective remedies. To examine suchaccountability, the thesis firstly surveys the evolution of public liability in violationsof the second chapter of the Instrument of Government, which is basedon obligations following the ECHR. Secondly, application of Articles 1, 2 and 9in the first chapter of the Instrument of Government is accounted for. Thirdly,the relation between principles and rights within the first chapter of the Instrumentof Government and the ECHR is examined.The findings within the three parts are thereafter brought together to determinehow public liability in violations of the first chapter of the Instrument ofGovernment works, concluding that accountability relating to that of the secondchapter of the Instrument of Government might be enforceable although thelack of case law and practice in general makes the prospect too uncertain for legalrepresentatives to strive for. Hence, leading to the final conclusion that the matterneeds to be inquired upon to a more extensive level – preferably in the formof a dissertation or as a Swedish Government Official Report.
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Récepteur radio-logicielle hautement numérisé / Highly digitized RF receiver for software defined radioHaghighitalab, Delaram 09 September 2015 (has links)
Aujourd'hui, il y a une augmentation du nombre de normes étant intégré dans des appareils mobiles. Les problèmes principaux sont la durée de vie de la batterie et la taille de l'appareil. L'idée d'un Radio-Logiciel est de pousser le processus de numérisation aussi près que possible de l'antenne. Dans cette thèse, nous présentons la première mise en œuvre d'un récepteur radio-logiciel complet basé sur Sigma-Delta RF passe-bande, y compris un LNA à gain variable (VGLNA), un ADC Sigma-Delta RF sous-échantillonné, un mélangeur bas-conversion RF numérique et un filtre de décimation polyphasé multi-étage multi-taux. Le VGLNA élargit la gamme dynamique du récepteur multi-standard pour atteindre les exigences des trois normes sans fil ciblées. Aussi une architecture mixte, en utilisant à la fois Source-Coupled Logic (SCL) et des circuits CMOS, il est proposé d'optimiser la consommation des circuits RF numériques. Par ailleurs, nous proposons une architecture de filtre en peigne à plusieurs étages avec décomposition polyphase à réduire la consommation d'énergie. Le récepteur est mesuré pour trois normes différentes dans la bande de 2.4 GHz, la bande ISM. Les résultats des mesures montrent que le récepteur atteint 79 dB, 73 dB et 63 dB de plage dynamique pour les normes Bluetooth, ZigBee et WiFi respectivement. Le récepteur complet, mis en œuvre dans le procédé CMOS 130 nm, a une fréquence centrale accordable de 300 MHz et consomme 63 mW sous 1.2 V. Comparé à d'autres récepteurs, le circuit proposé consomme 30% moins d'énergie, la plage dynamique est de 21 dB supérieur, IIP3 est de 6 dB supérieur et le facteur de mérite est de 24 dB supérieur. / Nowadays there is an increase in the number of standards being integrated in mobile devices. The main issues are battery life and the size of the device. The idea of a Software Defined Radio is to push the digitization process as close as possible to the antenna. Having most of the circuit in the digital domain allows it to be reconfigurable thus requiring less area and power consumption. In this thesis, we present the first implementation of a complete SDR receiver based on RF bandpass Sigma-Delta including a Variable-Gain LNA (VGLNA), an RF subsampled Sigma-Delta ADC, an RF digital down-conversion mixer and a polyphase multi-stage multi-rate decimation filter. VGLNA enlarges the dynamic range of the multi-standard receiver to achieve the requirements of the three targeted wireless standards. Also a mixed architecture, using both Source-Coupled Logic (SCL) and CMOS circuits, is proposed to optimize the power consumption of the RF digital circuits. Moreover, we propose a multi-stage comb filter architecture with polyphase decomposition to reduce the power consumption. The receiver is measured for three different standards in the 2.4 GHz ISM-band. Measurement results show that the receiver achieves 79 dB, 73 dB and 63 dB of dynamic range for the Bluetooth, ZigBee and WiFi standards respectively. The complete receiver, implemented in 130 nm CMOS process, has a 300 MHz tunable central frequency and consumes 63 mW under 1.2 V supply. Compared to other SDR receivers, the proposed circuit consumes 30% less power, the DR is 21 dB higher, IIP3 is 6 dB higher and the overall Figure of Merit is 24 dB higher.
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Développement d'une méthodologie pour l'évaluation de l'exposition réelle des personnes aux champs électromagnétiques / Development of a methodology for the assessment of the real-life exposure due to electromagnetic fieldsRojatkar, Ashish 30 March 2016 (has links)
Le travail présenté dans cette thèse a pour objectif l’étude des conditions nécessaires pour évaluer l'exposition radio fréquence (RF) due aux téléphones mobiles dans un scenario d’utilisation réelle et le développement d’une méthodologie permettant de prédire et de comparer les téléphones mobiles en fonction de leurs expositions RF réelles. Les téléphones mobiles sont caractérisés par leur débit d'absorption spécifique (DAS) et leur performance en émission et en réception (over-the-air, OTA). En utilisant le DAS et la puissance totale rayonnée (PTR), un indice d'exposition appelée l'indice SAROTA a été proposé précédemment afin de prévoir l'exposition réelle des téléphones mobiles. L’indice SAROTA sert ainsi de métrique permettant de comparer les téléphones mobiles. Afin de déterminer expérimentalement l’exposition réelle aux RF, plusieurs téléphones avec des modifications logicielles permettant d’enregistrer les paramètres du réseau, sont utilisés pour l’étude qui est menée comme suit : (a) caractérisation des outils et des ressources disponibles pour effectuer des mesures ciblées, (b) identification des ressources radio et des paramètres importants pour effectuer ces mesures, (c) étude de la mise en œuvre effective du mécanisme de contrôle de puissance observé dans un réseau mobile réel pour différents niveaux et de qualités du signal reçus, (d) étude de la corrélation entre la performance OTA des téléphones mobiles et l’étendue effective du contrôle de puissance appliquée par le réseau, (e) comparaison entre la valeur réelle de l’exposition et la valeur prédite en utilisant l’indice SAROTA. Comme les défis logistiques et techniques sont plus difficiles à surmonter pour les mesures dans un environnement multi-trajets extérieur, les expériences ont été limitées à des environnements intérieurs pour assurer une meilleure répétabilité des mesures. Lors d’une première phase de l’étude, la stabilité de l’environnement intérieur a été évaluée. Lors d’une deuxième phase, l’influence de la main sur le DAS et la PTR des téléphones mobiles ainsi que sur l’évaluation de l’exposition réelle prédite par l’indice SAROTA a été étudiée. Lors d’une troisième phase, un ensemble de téléphones mobiles identiques ont été modifiés et des mesures effectuées pour vérifier que l’indice SAROTA permet bien de prédire l’exposition réelle des personnes. / The work presented in the thesis is directed towards addressing the requirement for determining the radio frequency (RF) exposure due to mobile phones under typical usage/ real-life scenarios and also to develop a method to predict and compare mobile phones for their real-life RF exposure. The mobile phones are characterized for their specific absorption rate (SAR) and for transmit and receive performance given by the over-the-air (OTA) characterization. Using the SAR and the total radiated power (TRP) characterization, an exposure index referred to as the SAROTA index was previously proposed to predict the real-life exposure due to mobile phones which would also serve as a metric to compare individual phones. In order to experimentally determine the real-life RF exposure, various software modified phones (SMP) are utilized for the study. These phones contain an embedded software capable of recording the network parameters. The study is undertaken in the following order: (a) Characterization of the available tools and resources for performing targeted measurements/experiments, (b) identifying the important radio resource parameters and metrics to perform the targeted measurements, (c) investigation of the actual implementation of the power control mechanism in a live network for various received signal level and received quality environments, (d) investigating the correlation of the over-the-air performance of the mobile phones and the extent of actual power control realization, (e) comparing the actual exposure and the real-life exposure as predicted by the SAROTA index. Based on the logistical and technical challenges encountered, the experiments were restricted to indoor environments to enable repeatability. During the first phase of the study, the stability of the indoor environment was evaluated. During the second phase, the influence of hand phantom on the SAR and TRP of the mobile phones and the capability of the SAROTA index to predict the exposure was investigated. Further developing on the insights from the hand phantom experiments, in the third phase, a set of identical software modified phones were externally modified to alter the TRP performance and the methodology to determine the real-life exposure and also verify the capability of the SAROTA index to predict the exposure levels was investigated. The experiments demonstrate that the SAROTA index is capable of predicting the real-life exposure and comparing the mobile phones.
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