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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Research on electrical performance of differential pair design in package substrate

Huang, Chih-yi 18 July 2007 (has links)
Differential signaling is suitable for high speed signal transmission due to lower noise induction and higher common-mode noise rejection compared to its single-ended signaling counterpart. However, for a high performance differential transmission-line pair, excellent symmetry and appropriate design for substrate layer stack-up is necessary. Especially for a practical IC package substrate, differential transmission-line pair is inevitable for asymmetry because of considering the locations of IC pads and solderballs. Furthermore, different differential transmission-line pair architectures are also demanded in consideration of limited substrate floorplan space and substrate layer stack-up structures. In this thesis, several differential pairs have been implemented on the conventional 4-layer laminate package substrate. The consequent high frequency performances are measured using vector network analyzer and then compared by converting into mixed-mode S-parameters.
2

A Highly Abstracted Method of FPGA-Based Development for Secondary Surveillance Radar Transpond Detection

Watt, James Penn 01 June 2009 (has links)
Traditional FPGA-based digital design is based on writing hardware definition language (HDL) code from scratch. Time to market, cost of development, and the level of training required for designers all can be reduced with a simplified and abstracted design strategy. This project intends to demonstrate a graphical user interface (GUI) layer of abstraction on top of existing commercially produced design aids including MATLAB, Simulink, and Xilinx System Generator. This project performs and demonstrates a specific implementation example of a Secondary Surveillance Radar (SSR) message decoder as proof-of-concept for the abstracted design method. The abstracted digital design methods shown in this project can be adapted for use in other areas of development and research including digital signal processing and communications.
3

A study of NRD-guide basic structure and an integrated microstrip to NRD-guide transition

Tsai, Jin-lung 11 July 2004 (has links)
Comparing with other dielectric waveguides, NRD (nonradiative dielectric guides) presents advantages of ease of fabrication, low transmission loss, and absence of radiation from bends and discontinuities, making it suitable for realizing compact and high-performance millimeter wave integrated circuits. First, we study the EM theory of NRD to observe the characteristic affected by NRD geometric parameters and introduce multi-mode parameters to analyze mode coupling phenomena in bend and two-layer NRD structures. In order to promote NRD circuit application and transmission performance, we also study an integrated transition between microstrip line and NRD and mode suppressing technique. Finally, the structures mentioned above are all integrated in circuit application.
4

Automated Traffic Control for Smart Landing Facilities

Florin, Charles Henri 30 December 2002 (has links)
The Small Aircraft Transportation System (SATS) is a partnership between the FAA, the NASA, US aviation companies, universities and state and local aviation officials. The purpose of SATS is to develop a system to handle future increase in Air Traffic, reduce time-travel, develop automation in Air Traffic Control (ATC) and make better use of small aircraft and underused airports. The Smart Landing Facility (SLF) is an important part of the program. The SLF is a small airport upgraded with equipment to support SATS aircraft. Among the SLF equipment, SATS needs new detection equipment, and eventually automation. This thesis investigates different techniques to avoid data collision in aircraft radar responses, and to reduce delays between landings and take offs. First, the paper shows how and when the radar receiver can separate two overlapped radar responses. Second, to avoid transponders responses overlapping, requirements in terms of aircraft safety distance are computed, different conflicts in air traffic around the SLF are examined and a solution is proposed for each case. And finally, the thesis investigates how far SATS can go in developing an automatic ATC system and what the role of future human operator will be in ATC. / Master of Science
5

New Strategies to Improve Multilateration Systems in the Air Traffic Control

Mantilla Gaviria, Iván Antonio 14 June 2013 (has links)
Develop new strategies to design and operate the multilateration systems, used for air traffic control operations, in a more efficient way. The design strategies are based on the utilization of metaheuristic optimization techniques and they are intended to found the optimal spatial distribution of the system ground stations, taking into account the most relevant system operation parameters. The strategies to operate the systems are based on the development of new positioning methods which allow solving the problems of uncertainty position and poor accuracy that the current systems can present. The new strategies can be applied to design, deploy and operate the multilateration systems for airport surface surveillance as well as takeoff-landing, approach and enroute control. An important advance in the current knowledge of air traffic control is expected from the development of these strategies, because they solve several deficiencies that have been made clear, by the international scientific community, in the last years. / Mantilla Gaviria, IA. (2013). New Strategies to Improve Multilateration Systems in the Air Traffic Control [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/29688 / Alfresco
6

Modélisation CEM des équipements aéronautiques : aide à la qualification de l’essai BCI / EMC modeling of aeronautical equipment : support for the qualification of the BCI test

Cheaito, Hassan 06 November 2017 (has links)
L’intégration de l’électronique dans des environnements sévères d’un point de vue électromagnétique a entraîné en contrepartie l’apparition de problèmes de compatibilité électromagnétique (CEM) entre les différents systèmes. Afin d’atteindre un niveau de performance satisfaisant, des tests de sécurité et de certification sont nécessaires. Ces travaux de thèse, réalisés dans le cadre du projet SIMUCEDO (SIMUlation CEM basée sur la norme DO-160), contribuent à la modélisation du test de qualification "Bulk Current Injection" (BCI). Ce test, abordé dans la section 20 dans la norme DO-160 dédiée à l’aéronautique, est désormais obligatoire pour une très grande gamme d’équipements aéronautiques. Parmi les essais de qualification, le test BCI est l’un des plus contraignants et consommateurs du temps. Sa modélisation assure un gain de temps, et une meilleure maîtrise des paramètres qui influencent le passage des tests CEM. La modélisation du test a été décomposée en deux parties : l’équipement sous test (EST) d’une part, et la pince d’injection avec les câbles d’autre part. Dans cette thèse, seul l’EST est pris en compte. Une modélisation "boîte grise" a été proposée en associant un modèle "boîte noire" avec un modèle "extensif". Le modèle boîte noire s’appuie sur la mesure des impédances standards. Son identification se fait avec un modèle en pi. Le modèle extensif permet d’étudier plusieurs configurations de l’EST en ajustant les paramètres physiques. L’assemblage des deux modèles en un modèle boîte grise a été validé sur un convertisseur analogique-numérique (CAN). Une autre approche dénommée approche modale en fonction du mode commun (MC) et du mode différentiel (MD) a été proposée. Elle se base sur les impédances modales du système sous test. Des PCB spécifiques ont été conçus pour valider les équations développées. Une investigation est menée pour définir rigoureusement les impédances modales. Nous avons démontré qu’il y a une divergence entre deux définitions de l’impédance de MC dans la littérature. Ainsi, la conversion de mode (ou rapport Longitudinal Conversion Loss : LCL) a été quantifiée grâce à ces équations. Pour finir, le modèle a été étendu à N-entrées pour représenter un EST de complexité industrielle. Le modèle de l’EST est ensuite associé avec celui de la pince et des câbles travaux réalisés au G2ELAB. Des mesures expérimentales ont été faites pour valider le modèle complet. D’après ces mesures, le courant de MC est impacté par la mise en œuvre des câbles ainsi que celle de l’EST. Il a été montré que la connexion du blindage au plan de masse est le paramètre le plus impactant sur la distribution du courant de MC. / Electronic equipments intended to be integrated in aircrafts are subjected to normative requirements. EMC (Electromagnetic Compatibility) qualification tests became one of the mandatory requirements. This PhD thesis, carried out within the framework of the SIMUCEDO project (SIMulation CEM based on the DO-160 standard), contributes to the modeling of the Bulk Current Injection (BCI) qualification test. Concept, detailed in section 20 in the DO-160 standard, is to generate a noise current via cables using probe injection, then monitor EUT satisfactorily during test. Among the qualification tests, the BCI test is one of the most constraining and time consuming. Thus, its modeling ensures a saving of time, and a better control of the parameters which influence the success of the equipment under test. The modeling of the test was split in two parts : the equipment under test (EUT) on one hand, and the injection probe with the cables on the other hand. This thesis focuses on the EUT modeling. A "gray box" modeling was proposed by associating the "black box" model with the "extensive" model. The gray box is based on the measurement of standard impedances. Its identification is done with a "pi" model. The model, having the advantage of taking into account several configurations of the EUT, has been validated on an analog to digital converter (ADC). Another approach called modal, in function of common mode and differential mode, has been proposed. It takes into account the mode conversion when the EUT is asymmetrical. Specific PCBs were designed to validate the developed equations. An investigation was carried out to rigorously define the modal impedances, in particular the common mode (CM) impedance. We have shown that there is a discrepancy between two definitions of CM impedance in the literature. Furthermore, the mode conversion ratio (or the Longitudinal Conversion Loss : LCL) was quantified using analytical equations based on the modal approach. An N-input model has been extended to include industrial complexity. The EUT model is combined with the clamp and the cables model (made by the G2ELAB laboratory). Experimental measurements have been made to validate the combined model. According to these measurements, the CM current is influenced by the setup of the cables as well as the EUT. It has been shown that the connection of the shield to the ground plane is the most influent parameter on the CM current distribution.
7

Responsabilité sociétale et ancrage territorial d'une entreprise de services urbains : le cas de Lyonnaise des Eaux / Corporate social responsibility and territorial embeddedness of a utilities company : Lyonnaise des Eaux case study

Batisse, Julien 10 July 2015 (has links)
Dans un contexte de réflexions contemporaines sur la durabilité des services urbains d’eau potable, nous nous intéressons à la stratégie de responsabilité sociétale de Lyonnaise des Eaux comme contribution à la mise en mots et mise en œuvre du développement durable dans ce secteur d’activité. L’objectif de ce travail est d’analyser et questionner la stratégie de responsabilité sociétale de l’entreprise (RSE) pour y mettre en lumière d’une part ses causes, processus, finalités, et en comprendre, d’autre part, les impacts sur l’ancrage territorial de l’entreprise. Le mouvement de territorialisation de la RSE s’exprime dans un processus d’interaction global-local aboutissant à la régionalisation de la stratégie RSE de Lyonnaise des Eaux et à son incarnation locale sous la forme de projets développement durable. A partir de l’exemple de la gestion de l’eau potable dans la métropole bordelaise, nous avons étudié et mené deux projets de développement durable au sein de Lyonnaise des Eaux : le premier centré sur la gestion des usagers en situation de précarité hydrique ; le second portant sur l’accompagnement des usagers à la gestion durable de leur consommation d’eau. L’exploration des conditions territoriales de faisabilité de ces projets met en lumière les possibilités offertes à l’entreprise de répondre aux enjeux du territoire en limitant l’impact lié à son activité et de générer les ressources spécifiques nécessaires à son intégration dans des dispositifs locaux d’innovation. L’analyse spatiale de la responsabilité sociétale montre qu’elle est aussi l’interface négociée de l’adaptation et de l’action territorialisée de l’entreprise aux différents échelons. / In a context of contemporary reflections on the sustainability of urban water utilities, we focus on Lyonnaise des Eaux’s corporate social responsibility strategy as a contribution to putting into words and implementing sustainable development in this sector. This work aims at analyzing on the one hand the causes, processes, goals of Lyonnaise des Eaux CSR strategy and understanding on the other hand the impact of these strategies on the company’s territorial embeddedness. CSR's territorial impetus is expressed via a global-local interaction process leading to the regionalization of Lyonnaise des Eaux CSR strategy and, its local embodiment through sustainable development projects. Based on the example of water management in the Bordeaux metropolis, we have studied and conducted two sustainable development projects within the company, one focused on water poverty management and the other focused on sustainable management of domestic water consumption. Exploring the feasibility conditions of these CSR projects highlights the opportunities for the company to meet the challenges of the territory by limiting the impact associated with its business or generate specific resources necessary for its integration into local innovation systems. The territorial approach of corporate responsibility strategy shows that it also appears as a negotiated interface used by Lyonnaise des Eaux for its adaptation and action at different scales.
8

Využití SSR módu S pro řízení pohybů letadel a vozidel po ploše letiště / Exploitation of the Mode S SSR for aerodrome surface movement control of aircraft & vehicles

Drápal, Stanislav January 2015 (has links)
The topic of this thesis relates to the state-of-art technologies and systems used for airport ground movements monitoring and guidance. Emphasis is placed on mode S of SSR, its characteristics, applications and avionics requirements. This thesis further comprises analysis of Brno - Turany Airport and it presents a new multilateration system including economical analysis, which would be used for aerodrome ground movements monitoring.
9

Adaptive Suppression of Interfering Signals in Communication Systems

Pelteku, Altin E. 21 April 2013 (has links)
The growth in the number of wireless devices and applications underscores the need for characterizing and mitigating interference induced problems such as distortion and blocking. A typical interference scenario involves the detection of a small amplitude signal of interest (SOI) in the presence of a large amplitude interfering signal; it is desirable to attenuate the interfering signal while preserving the integrity of SOI and an appropriate dynamic range. If the frequency of the interfering signal varies or is unknown, an adaptive notch function must be applied in order to maintain adequate attenuation. This work explores the performance space of a phase cancellation technique used in implementing the desired notch function for communication systems in the 1-3 GHz frequency range. A system level model constructed with MATLAB and related simulation results assist in building the theoretical foundation for setting performance bounds on the implemented solution and deriving hardware specifications for the RF notch subsystem devices. Simulations and measurements are presented for a Low Noise Amplifer (LNA), voltage variable attenuators, bandpass filters and phase shifters. Ultimately, full system tests provide a measure of merit for this work as well as invaluable lessons learned. The emphasis of this project is the on-wafer LNA measurements, dependence of IC system performance on mismatches and overall system performance tests. Where possible, predictions are plotted alongside measured data. The reasonable match between the two validates system and component models and more than compensates for the painstaking modeling efforts. Most importantly, using the signal to interferer ratio (SIR) as a figure of merit, experimental results demonstrate up to 58 dB of SIR improvement. This number represents a remarkable advancement in interference rejection at RF or microwave frequencies.

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