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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.
51

Filterdesign och hårdvarukonstruktion för FMCW-radar

Eriksson, Oscar January 2007 (has links)
<p>Den här högskoleavhandlingen beskriver designen av ett IF-filter samt hårdvarukonstruktion av en ny 77 GHz FMCW-radar demonstrator. Syftet med demonstratorn är att illustrera hur kisel germanium-, SiGe, teknologi kan användas istället för den mer vedertagna men dyrare gallium arsenik-, GaAs, teknologin. Den gamla radar-prototypen vilken Acreo AB utvecklat är funktionell men behöver konstrueras om för att bättre kunna utvärdera radarprestandan. I avhandlingen presenteras grundläggande radarteori och ekvationer för att underlätta förståelsen av de olika systemblocken. Rapporten beskriver också systemarkitekturen och hur dess funktionalitet kommer att testas. Det omdesignade IF-filtret har simulerats i en PSpice-simulator och ett prototypkort av detta har tillverkats för mätningar. Ett 4-lagers kretskort av hela systemet har tagits fram i Orcad Layout. Slutligen innehåller rapporten förslag på förbättringar till nästa demonstratorversion.</p> / <p>This bachelor thesis describes the design of an IF-filter and the hardware construction of a new version of a 77 GHz FMCW-radar demonstrator. The purpose of the demonstrator is to illustrate how the silicon germanium-, SiGe, technology could be used instead of the more conventional but also much more expensive gallium arsenide-, GaAs, technology. The old radar prototype that Acreo AB has developed is fully functional but needs to be redesigned to be able to evaluate the radar performance in a better way. The thesis presents the basic radar theory and equations to help understanding the construction of the system blocks. The report also describes the system architecture and how its functionality should be tested. The redesigned IF-filter has been simulated in a PSpice simulator and a prototype has been manufactured and measured. A 4-layer PCB-board of the whole system was done in Orcad Layout. Finally the report is concluded with suggestions on improvements for the next demonstrator version.</p>
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52

Optimization of a 50 MHz Frequency Modulated Continuous Wave radar system for the study of auroral E-region coherent backscatter

Perry, Gareth William 24 August 2010
A 50 MHz Frequency Modulated Continuous Wave (FMCW) radar system, developed at the University of Saskatchewan to provide improved spatial and temporal resolution measurements of auroral E-region plasma processes, introduces ambiguous spectral information, due to spectral ghosting, for scattering events in which multiple radar echoes are detected. This thesis identifies two Linearly Frequency Modulated (LFM) radar waveforms used by the FMCW system as the source of the ghosting. An analysis procedure designed to counteract the spectral ghosting problem is developed but is not an ideal solution, and therefore replacement of the LFM waveforms is recommended.<p> A detailed investigation of alternative radar waveforms using the Ambiguity Function and Ambiguity Diagram techniques is performed. A frequency coded continuous wave radar waveform based on a composite Costas sequence is proposed as a successor to the LFM waveforms. The composite Costas radar waveform will conserve the spatial and temporal resolutions extended by the LFM waveforms and preclude any spectral ghosting. Implementing the proposed radar waveform and avoiding receiver saturation issues with the mono-static FMCW radar system in which both the transmitting and receiving antenna arrays are simultaneously and continuously active and geographically co-located is also discussed.<p> In addition to this, two 50 MHz backscatter events are presented in this thesis to demonstrate the effectiveness of the FMCW system, notwithstanding the spectral ghosting complication. The first event from November 21, 2009 is identified as a Type 1 instability and the second from September 13, 2009 is identified as a Type 2 instability which lasted for ~ 16 minutes. Linear plasma fluid theory is used to provide a brief interpretation of both scattering events.
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53

Filterdesign och hårdvarukonstruktion för FMCW-radar

Eriksson, Oscar January 2007 (has links)
Den här högskoleavhandlingen beskriver designen av ett IF-filter samt hårdvarukonstruktion av en ny 77 GHz FMCW-radar demonstrator. Syftet med demonstratorn är att illustrera hur kisel germanium-, SiGe, teknologi kan användas istället för den mer vedertagna men dyrare gallium arsenik-, GaAs, teknologin. Den gamla radar-prototypen vilken Acreo AB utvecklat är funktionell men behöver konstrueras om för att bättre kunna utvärdera radarprestandan. I avhandlingen presenteras grundläggande radarteori och ekvationer för att underlätta förståelsen av de olika systemblocken. Rapporten beskriver också systemarkitekturen och hur dess funktionalitet kommer att testas. Det omdesignade IF-filtret har simulerats i en PSpice-simulator och ett prototypkort av detta har tillverkats för mätningar. Ett 4-lagers kretskort av hela systemet har tagits fram i Orcad Layout. Slutligen innehåller rapporten förslag på förbättringar till nästa demonstratorversion. / This bachelor thesis describes the design of an IF-filter and the hardware construction of a new version of a 77 GHz FMCW-radar demonstrator. The purpose of the demonstrator is to illustrate how the silicon germanium-, SiGe, technology could be used instead of the more conventional but also much more expensive gallium arsenide-, GaAs, technology. The old radar prototype that Acreo AB has developed is fully functional but needs to be redesigned to be able to evaluate the radar performance in a better way. The thesis presents the basic radar theory and equations to help understanding the construction of the system blocks. The report also describes the system architecture and how its functionality should be tested. The redesigned IF-filter has been simulated in a PSpice simulator and a prototype has been manufactured and measured. A 4-layer PCB-board of the whole system was done in Orcad Layout. Finally the report is concluded with suggestions on improvements for the next demonstrator version.
Read more
54

Optimization of a 50 MHz Frequency Modulated Continuous Wave radar system for the study of auroral E-region coherent backscatter

Perry, Gareth William 24 August 2010 (has links)
A 50 MHz Frequency Modulated Continuous Wave (FMCW) radar system, developed at the University of Saskatchewan to provide improved spatial and temporal resolution measurements of auroral E-region plasma processes, introduces ambiguous spectral information, due to spectral ghosting, for scattering events in which multiple radar echoes are detected. This thesis identifies two Linearly Frequency Modulated (LFM) radar waveforms used by the FMCW system as the source of the ghosting. An analysis procedure designed to counteract the spectral ghosting problem is developed but is not an ideal solution, and therefore replacement of the LFM waveforms is recommended.<p> A detailed investigation of alternative radar waveforms using the Ambiguity Function and Ambiguity Diagram techniques is performed. A frequency coded continuous wave radar waveform based on a composite Costas sequence is proposed as a successor to the LFM waveforms. The composite Costas radar waveform will conserve the spatial and temporal resolutions extended by the LFM waveforms and preclude any spectral ghosting. Implementing the proposed radar waveform and avoiding receiver saturation issues with the mono-static FMCW radar system in which both the transmitting and receiving antenna arrays are simultaneously and continuously active and geographically co-located is also discussed.<p> In addition to this, two 50 MHz backscatter events are presented in this thesis to demonstrate the effectiveness of the FMCW system, notwithstanding the spectral ghosting complication. The first event from November 21, 2009 is identified as a Type 1 instability and the second from September 13, 2009 is identified as a Type 2 instability which lasted for ~ 16 minutes. Linear plasma fluid theory is used to provide a brief interpretation of both scattering events.
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55

Target Detection By The Ambiguity Function Technique And The Conventional Fourier Transform Technique In Frequency Coded Continuous Wave Radars

Akangol, Mehmet 01 December 2005 (has links) (PDF)
Continuous Wave (CW) radars are preferred for their low probability of intercept by the other receivers. Frequency modulation techniques, the linear frequency modulation (LFM) technique in particular, are commonly used in CW radars to resolve the range and the radial velocity of the detected targets. The conventional method for target detection in a linear FMCW radar makes use of a mixer followed by a low-pass filter whose output is Fourier transformed to get the range and velocity information. In this thesis, an alternative target detection technique based on the use of the Ambiguity Function (AF) will be investigated in frequency modulated CW radars. Results of the AF-based technique and the conventional Fourier-based technique will be compared for different target detection scenarios.
56

Fusion de capteurs radars et infrarouge pour l'aide au pilotage d'hélicoptère

Mazouni, Karim 02 December 2011 (has links) (PDF)
Cette thèse, effectuée au Laboratoire d'Electronique, Antennes et Télécommunications, a pour objectif la conception d'un système de détection en bande millimétrique dans le cadre de deux projets. Le projet INFRADAR en collaboration avec des partenaires industriels (ATE et Opéra Ergonomie) vise à développer un système d'aide au pilotage d'hélicoptère par la réalisation d'un système anticollision capable de détecter des obstacles comme les lignes à hautes tensions ou les pylônes électriques à longue portée. Le projet Sakura en collaboration avec un institut étranger (Electronic Navigation Research Institute, ENRI, of Tokyo) se focalise sur la détection d'objets et de débris sur piste d'aéroport. Le premier chapitre est un état de l'art des radars et antennes millimétriques. L'antenne retenue pour notre application est un réseau réflecteur(reflectarray). Le deuxième chapitre est consacré à l'étude de cellules élémentaires originales qui permettent la conversion de polarisation et la stabilité en fréquence. Le chapitre trois décrit les 3 réseaux réflecteurs développés avec pour objectif l'obtention d'une polarisation circulaire, d'un réseau réflecteur multi-lobes, d'un réseau réflecteur bas bruit. Le chapitre quatre illustre les différentes campagnes de mesures réalisées à Tokyo et Sendaï lors du Projet Sakura. Les résultats sont confrontés à un modèle théorique afin de comprendre les limites du système. Enfin nous discutons dans le chapitre cinq des mesures réalisées à Aix en Provence et Sophia Antipolis dans le cadre du Projet INFRADAR. Le projet commençant à peine, les premiers résultats présentés permettent d'entrevoir le potentiel de notre système pour l'aide au pilotage.
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57

Design of an Ultra-Wideband Frequency-Modulated Continuous Wave Short Range Radar System for Extending Independent Living

Nguyen, Toai-Chi 01 April 2021 (has links) (PDF)
Falls in the disabled and elderly people have been a cause of concern as they can be immobilized by the fall and have no way to contact others and seek assistance. The proposed frequency modulated continuous wave (FMCW) short range radar (SRR) system, which uses ultra-wideband (UWB) signals can provide immediate assistance by monitoring and detecting fall events. The unique characteristics of this system allow for a frequency-based modulation system to carry out triangulation and sense the location of the fall through the usage of a continuous chirp signal that linearly sweeps frequency. This project focuses on the development, design and simulation of a ring oscillator that exhibits the frequency modulated signal on a single integrated circuit chip. The ring oscillator is controlled by a voltage ramp signal generator and a voltage to current (V-I) converter. The circuit is designed in Cadence using TSMC 180nm process technology and operates in the frequency range of 3.409 GHz to 5.349 GHz with a spectral bandwidth of 1.94 GHz, which meets the Federal Communications Commission’s standards for unlicensed ultra-wideband transmissions.
58

Multi-Dimensional Digital Signal Processing in Radar Signature Extraction

Randeny, Tharindu D. January 2015 (has links)
No description available.
59

Advances in displacement monitoring of the Earth’s surface based on satellite InSAR analysis and development of drone SAR system / 衛星InSAR解析とドローンSARシステム開発による地表変動モニタリングの高度化

Shigemitsu, Yutaro 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第25263号 / 工博第5222号 / 新制||工||1996(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 林 為人, 教授 小池 克明, 講師 石塚 師也, 教授 須崎 純一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
60

Micro-Shivering Detection : Detection of human micro-shivering using a 77 GHz radar

Razzaghi, Elyas, Van Hoek, Arno January 2019 (has links)
Radars have been under steady development to track, identify, image, and classify targets. Modern radar systems, with the help of embedded systems, have additional comprehensive signal processing capabilities. They can extract useful information from very noisy data, e.g. interference from the environment and unwanted echoes which is collectively known as clutter in radar terms. Concerning the healthcare industry, radar applications for detection of vital signs, i.e. breathing and heart rate, have been extensively developed during the last few decades. Modern radar systems are expected to be a large part of non-intrusive monitoring in the coming smart home industry, where vital signs need to be monitored in the currently aging population. The research presented here is to break new ground in the radar-based healthcare technology, enabling detection of cold-induced shivering to such level that the micro-shivering can be clearly identified. To simplify the radar software optimization, a commercially available radar kit with demo application and a muscle model system using a vibration generator is used. The model is quantified through precise measurements. A simulated human body vital sign plus shivering is applied. By optimizing the radar software, the shivering amplitude and frequency are measured.
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