Rozprawy doktorskie: „UWB APPLICATIONS”

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Ripoche, Olivier. "Miniaturisation d’antennes en bande VHF pour applications spatiales". Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/11383/1/ripoche_partie_1_sur_2.pdf.

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Le développement de l’électronique embarquée et miniaturisée est pleinement d’actualité de nos jours, dans les domaines tels que l’armement, la médecine, et les télécommunications. La miniaturisation des antennes large-bande, opérationnelles sur plus d’une décade, présentent un défi particulier. Ces travaux de thèse proposent de travailler sur la miniaturisation d’une antenne spirale, afin d’en réduire l’encombrement, à savoir son diamètre, tout en conservant au mieux ses caractéristiques de rayonnement et polarisation intrinsèques. Cette recherche sera appliquée à la bande des Très hautes Fréquence (Very High Frequencies – VHF), allant de 30MHz à 300MHz La géométrie inédite proposée consiste à associer à une antenne spirale un ensemble d’anneaux résonnants, dont le diamètre n’excède pas celui de la spirale, et permettant de diminuer la fréquence basse de fonctionnement. Pour un ensemble de cinq anneaux associé à la spirale, la réduction de la fréquence basse de fonctionnement est de plus de 30%. Pour deux antennes spirales de même fréquence basse de fonctionnement, l’antenne miniaturisée a donc un diamètre réduit de 30%, soit une surface réduite de 50%. Les performances de l’état de l’art d’après lesquelles les réductions sur le diamètre des antennes spirales n’excèdent pas 15% sont donc dépassées. De plus, d’après cet état de l’art, les méthodes de réduction appliquées aux antennes large bande dégradent en général le gain et l’axial ratio dans les bandes basses de fréquences de fonctionnement. La méthode proposée permet de conserver l’efficacité de l’antenne, voire de l’augmenter, dans les fréquences proches de la fréquence basse de fonctionnement. Le rayonnement de l’antenne spirale miniaturisée dans la bande passante de l’antenne sans anneaux n’est pour autant pas modifiée. Ces résultats très encourageant ont été confirmés par la mesure d’antennes spirales miniaturisées, réalisées pour un diamètre de 8cm et de 1m : une réduction de 30% du diamètre sans dégradation du rayonnement a été observée. Les mesures ont par ailleurs donné lieu à l’étude de la réalisation d’une antenne en bande VHF, avec pour implication les problématiques de réalisation (masse, encombrement, résistance mécanique) et de mesure (isolation, effets parasites en VHF avec une longueur d’onde de 4m).

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2

Liu, Li, i 劉荔. "Compact planar UWB antennas for wireless device applications". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/207199.

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The thesis report presents the designs of compact planar ultra-wideband (UWB) antennas for wireless devices applications. Three main designs of UWB antennas are studied, namely, single UWB antennas, UWB multiple-input-multiple-out(MIMO)antennas, and transparent UWB antennas on the screens of mobile phones. For single UWB antennas, the designs of two compact planar monopole antennas with compact sizes of 26×28 mm2and 30×39.3mm2are presented. The UWB operations of the antennas are achieved using a ground slot under the feed line, offsetting the feed line and the radiator from the middle of the ground plane and smoothly transforming the feed line. Simulation and measurement show that the two antennas can achieve an ultra-wide bandwidth with approximately omnidirectional patterns. A deep notch-band in5.1-5.85 GHz is created in one of the UWB antennas by employing two pairs of meander lines (MLs), one pair being close to the feed line and the other pair along the upper edge of the ground plane. At the notch frequency, the simulated efficiency is only 4%. Three compact UWB-MIMO antennas with very compact sizes of 26×40 〖mm〗^2, 21×38 〖mm〗^2, and 22×36 〖mm〗^2 are designed. Each of them is designed using two UWB antenna elements perpendicularly or symmetrically placed. Different techniques such as using ground stubs besides the radiators, cutting inclined slots on the ground, and adding a T-shaped protruding from ground are proposed to lower mutual coupling between the two antenna elements. One of the antennas is designed to generate a notched band in 5.15-5.85 GHz using two ground strips. Simulation and measurement results show that these antennas can cover the entire UWB of 3.1-10.6GHz with mutual coupling of less than -15 dB, and envelope correlation coefficient of less than 0.1. An UWB antenna is designed using a transparent conductive film for applications on mobile phone screens. The effects of a finger touching the screen are studied. Results show that, with the radiator on the bottom side of the screen and a thin film with a thickness of 0.05 mm on the top side to separate the finger and the antenna, the effects of the finger can be minimized. In measurement of monopole antennas with small ground planes, due to the feeding cable used, there are always discrepancies between the simulated and measured results in radiation patterns, efficiencies, and gains at lower frequencies. To verify that the discrepancies in the results of these studies are indeed due to the feeding cable used in measurement, the models of the feeding cables are developed and used for simulation. Results show that, by using the cable model, the simulated and measured results in radiation patterns, efficiencies, and gains agree very well.
published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy

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3

Jose, Sajay. "Design of RF CMOS Power Amplifier for UWB Applications". Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/36391.

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Ever since the FCC allocated 7.5 GHz (from 3.1 GHz to 10.6 GHz) for ultra wideband (UWB) technology, interest has been renewed in both academic and industrial circles to exploit this vast spectrum for short range, high data rate wireless applications. The great potential of UWB lies in the fact that it can co-exist with the already licensed spectrum users and can still pave the way for a wide range of applications. However, this wide bandwidth complicates the circuit level implementation of key RF blocks like the power amplifier (PA), transmit/receive switch, low noise amplifier (LNA) and mixers in an UWB transceiver. Though expensive technologies like SiGe or GaAs have been used for transceiver realizations, the ultimate goal is to have a single-chip, low-cost solution which can only be achieved by using CMOS technology. Nevertheless, some of the inherent limitations of CMOS like lower fT of transistors make the design of UWB circuits in CMOS an extremely challenging task. Two proposals- Multi-Band OFDM and Direct-Sequence CDMA have been put before the IEEE 802.15.3a task group to decide on the industry standard for the commercial deployment of this technology. Though the debate on which standard is better has not been resolved, proponents of both the groups have already begun to develop prototypes of their respective proposals. This thesis describes the design of a key RF block in the UWB transceiver - the Power Amplifier. For the first part of this work, a PA suitable for MB-OFDM specifications was designed and fabricated in TSMC 0.18um CMOS technology. The class-AB PA is able to cover the lower UWB frequency band from 3.1 GHz to 4.75 GHz and delivers an output power of -2 dBm at 4 GHz. Simulated results show a gain of 19Â±2 dB achieved over the entire band and the PA consumes 36.54 mW from a 1.8V supply. In the second part of this work, a PA that meets the DS-CDMA specifications was designed and fabricated. This PA operates in the class-AB regime, delivering an output power of -4.2 dBm with input-1dB compression point at -22 dBm. Complete design and implementation was done using TSMC 0.18um CMOS technology and it consumes a very low power of 25 mW, while realizing a flat gain of 19Â±1 dB across the whole band of operation. All the above mentioned results are from simulations in SpectreRF and measurements are yet to be taken. Additional features like power ON/OFF scheme and output impedance control has also been incorporated in the design.
Master of Science

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Volos, Haris I. "Ultra Wideband Ranging and Link Budget Design for Naval Crane Applications". Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33652.

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In this thesis a UWB-based ranging scheme is designed, simulated, implemented and tested. This system was designed to address the problem of safely unloading cargo crates to ships in the open seas. UWB antennas are placed on the four corners of the cargo crate, providing the information needed to a ranging/positioning algorithm that estimates the orientation and distance of the ship's deck from the crate. Furthermore, the system is successfully tested in a 1/24 scale demonstration. In addition to the UWB ranging application, this thesis evaluates an already proposed modification to the traditional narrowband link budget based on the Friis transmission formula. The proposed modification replaces frequency-domain parameters with time-domain values to handle the wide bandwidth of UWB systems. The proposed approach is shown via measurements to be much more accurate than the traditional technique.
Master of Science

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Morsy, Mohamed Mostafa. "DESIGN AND IMPLEMENTATION OF MICROSTRIP MONOPOLE AND DIELECTRIC RESONATOR ANTENNAS FOR ULTRA WIDEBAND APPLICATIONS". OpenSIUC, 2010. https://opensiuc.lib.siu.edu/dissertations/169.

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Ultra wide-band (UWB) technology is considered one of the very promising wireless technologies in the new millennium. This increases the demand on designing UWB antennas that meet the requirements of different UWB systems. In this dissertation, different UWB antennas are proposed such as an antenna that covers almost the entire UWB bandwidth, 3.5-11 GHz, as defined by the federal communication commission (FCC). This antenna has a size of 50×40×1.5mm3. Miniaturized worldwide UWB antennas are also introduced. Miniaturized worldwide UWB antennas that have compact sizes of (30×20×1.5) mm3, and (15×15×1.5) mm3 are also investigated. The designed worldwide UWB antennas cover the UWB spectrums defined by the electronic communication committee (ECC), 6-8.5 GHz, and the common worldwide UWB spectrum, 7.4-9 GHz. A system consisting of two identical antennas (transmitter and receiver) is built in the Antennas and Propagation Lab at Southern Illinois University Carbondale (SIUC) to test the coupling properties between every two identical antennas. The performance of that system is analyzed under different ii conditions to guarantee that the transmitted signal will be correctly recovered at the receiver end. The designed UWB antennas can be used in many short range applications such as wireless USB. Wireless USB is used in PCs, printers, scanners, laptops, MP3 players, hard disks and flash drives. A new technique is introduced to widen the impedance bandwidth of dielectric resonator antennas (DRAs). DRA features compactness, low losses, and wideband antennas. Different compact UWB DRAs are investigated in this dissertation. The designed DRAs cover a wide range of frequency bands such as, 6.17-24GHz, 4.23-13.51GHz, and 4.5-13.6GHz. The designed DRAs have compact sizes of 1×1×1.5cm3, 0.9×0.9×1.32cm3, 0.6×0.6×1cm3, and 0.6×0.6×0.9cm3; and cover the following frequency bands 4.22-13.51GHz, 4.5-13.6GHz, 6.1-23.75GHz, and 6.68-26.7GHz; respectively. The proposed DRAs may be used for applications in the X, Ku and K bands such as military radars and unmanned airborne vehicles (UAV).

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Gao, Yang. "Robust cooperative positioning using DGPS and UWB for V2X applications". Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/42843/.

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Road transportation injuries, environmental pollution, and traffic congestion have resulted in a considerable cost to society annually. They have led to an increasing demand for a new generation of Intelligent Transportation Systems (ITS) road applications, which promise to tackle these widespread issues. A common element of such applications is the positioning system, and its performance has been highlighted as one of the key enablers. With the rapid expansion of Global Navigation Satellite Systems (GNSS), satellite-based positioning and navigation will continue to be the predominant positioning solution for most of ITS road applications. GNSS positioning systems offer global coverage, they are primarily free of charge, operate in all weather conditions, and are available all day, every day. However, there are challenges for GNSS-based positioning for ITS applications; in particular, the limited availability and degraded performance of GNSS signals in urban canyons. These challenges could impede the adoption of ITS applications, such as collision avoidance systems, lane departure warning systems, connected and autonomous vehicles. There is a gap between the positioning performance of GNSS-based systems and the positioning performance demanded by ITS applications. To bridge this gap, this research considers multi-sensor integration and cooperative positioning based on vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-pedestrian communications (collectively known as V2X communication). In comparison to other radio frequency augmentation techniques, Ultra-Wideband (UWB) is of particular interest for multi-sensor integration due to its fine time resolution and robust performance in high signal multipath environments. In addition to this benefit, Dedicated Short Range Communication (DSRC), as a key enabling communication component in V2X communication, not only allows vehicles to exchange their position information but also to share traffic safety-related information such as real-time congestion, accident and incident details, and variable speed limits. By taking advantage of DSRC, a vehicle in a GNSS hostile environment can calculate its position based on data shared from surrounding road users. This thesis utilises Global Positioning System (GPS) as a representative of GNSS and proposes to augment Differential GPS (DGPS) with UWB ranging observations attained from surrounding vehicles and infrastructure. It is accomplished by tightly integrating double-difference (DD) code pseudo-range GPS observations and UWB ranging observations using a Robust Kalman Filter. The performance of the proposed Robust Cooperative Positioning (RCP) method is evaluated using real and simulated GPS code pseudo-range and UWB ranging observations supported by assumed DSRC transmission. This thesis carries out a thorough assessment of the ranging performance, error sources and positioning performance of the Thales UWB Lock-on Model LD2. The assessment is completed by conducting a series of tests in different static and dynamic situations. In addition to this in-field assessment of the UWB device, the positioning performance of the proposed RCP method is demonstrated in both favourable and hostile GPS environments. The proposed RCP method effectively eliminates the impact of observed outliers, and the integrated RCP solution outperforms the DGPS-only solution, especially when the GPS signal is partially or fully obstructed. The results based on simulated UWB ranging observations and real GPS code pseudo-range observations on the roof of the Nottingham Geospatial Building achieve sub-metre three-dimensional accuracies when three DD code pseudo-ranges and four UWB ranging observations are available.

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Fabbri, Davide <1990&gt. "Energy Autonomous RF Tags for Sensing and UWB Localization Applications". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9610/1/Fabbri_Davide_tesi.pdf.

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In the new scenarios foreseen by the Internet of Things (IoT), billions of smart devices are worldwide spread and connected to each other to provide sensing information or to detect and locate tagged items with high accuracy using cheap, energy autonomous, and disposable tags. In this context, the use of energy harvesting techniques to supply devices, nowadays, plays an important role in order to create energy autonomous systems able to reduce the use of batteries, by containing the infrastructure maintenance costs, for better environmental safeguard. Hence, by considering real scenarios in which tags can be placed, where only few µW are available as input source, low-power design aspects, strategies and policies have to be taken into account during the implementation approach. In order to cover all possible solutions, radio-frequency and light energy harvesting sources are considered to build battery-less nodes. Thus, PV passive tags for indoor and outdoor environments will be presented, which allows the creation of long range Wireless Sensor Networks (WSNs) used for environmental monitoring. In harsh scenarios where the presence of obstacles makes energy scavenging operations more critical, radio-frequency sources can be adopted to build battery-less, individually addressable, UHF tags, featuring high-directive behaviour with single-monopole structures or an orientation-independent usage through double-monopole architectures. UWB circuitry for localization purposes will be introduced in both configurations: transmitting and backscattering tag solutions adopting, in the first case, a customized protocol for the UHF link, while in the second one, a RFID integration compliant with European standard, by making this activity more attractive for the market.

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Zhao, Jun. "Silicon-Based RFIC Multi-band Transmitter Front Ends for Ultra-Wideband Communications and Sensor Applications". Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/28864.

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Fully integrated Ultra-Wideband (UWB) RFIC transmitters are designed in Si-based technologies for applications such as wireless communications or sensor networks. UWB technology offers many unique features such as broad bandwidth, low power, accurate position location capabilities, etc. This research focuses on the RFIC front-end hardware design issues for proposed UWB transmitters. Two different methods of multiband frequency generation ----- using switched capacitor VCO tanks and frequency mixing with single sideband mixers ----- are explored in great detail. To generate the required UWB signals, pulse generators are designed and integrated into the transmitter chips. The first prototype UWB transmitter is designed in Freescale Semiconductor 0.18Î¼m SiGe BiCMOS technology for operation over three 500 MHz bands at center frequencies of 4.6/6.4/8.0 GHz, and generates pulses supporting differential BPSK modulation. The transmitter output frequency is controlled by a two-bit code which sets the state of a switched capacitor tank array for coarse tuning of the VCO. While selecting between the different bands, the transmitter is capable of settling and re-transmitting in less than 0.7Î¼s using an integrated, wide band phase-locked loop (PLL). Various issues such as mismatch/inaccuracy of the pulses and high power consumption of the prescaler were identified during the first design and were addressed in subsequent design revisions. The pulse generator is a critical part of the proposed UWB transmitter. The initial pulse generator design used CMOS delay lines and logic gates to synthesize the required pulse bandwidth; however this approach suffered from inaccurate pulse timing control due to delay time sensitivity to device modelling and process variations. Subsequently, a novel pulse generator design capable of achieving accurate timing control was implemented using digital logic and a fixed oscillator frequency to provide timing information, integrated into a modified transmitter circuit, and subsequently fabricated in Jazz Semiconductor's 0.18Î¼m CA18 RFCMOS process. Experimental results confirm the generation of accurate one-nanosecond pulses. Finally, a new multiband UWB transmitter based on a new single sideband (SSB) resistive mixer with superior linearity and zero static power consumption was also designed and fabricated using Jazz CA13 0.13Î¼m RF CMOS process. This design is based on a fixed frequency phase-locked VCO and generates different bands through frequency mixing. In the prototype design, two additional carrier frequencies are generated from the VCO center frequency (5 GHz) by mixing it with its output divided-by-4 (1.25 GHz). By switching the relative I/Q phases of the LO/IF inputs to this single side band mixer, either the upper side band (6.25 GHz) or lower side band (3.75 GHz) frequency is selected at the mixer output, while the other sideband is rejected. Simulation results show that the transmitter is capable of generating the desired carrier frequencies while suppressing the image component by more than 40 dB. Overall, this work has explored various aspects of UWB transmitter design and implementations in fully integrated silicon chips. The major contributions of this work include: proposed hardware architectures for pulse-based multiband UWB transmitters; implemented a fully integrated multiband UWB transmitter with embedded phase-locked switched-tank VCO capable of wide frequency tuning; demonstrated an all digital pulse generator capable of generating accurate one-nanosecond pulse trains in the presence of various mismatches; and investigated resistive SSB mixer topologies and their implementation in a multiband UWB generation architecture.
Ph. D.

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Rosales, Marc. "Study of SiGe HPT for radio over fiber applications". Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1101/document.

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Ce travail de thèse présente le développement de phototransistors bipolaires à hétérojonction (HPT) SiGe/Si mis en œuvre dans une technologie de processus 80GHz SiGe bipolaire pour des applications de transmission Radio-sur-Fibre. Le cas particuliers d'un réseau domestique sans fil à infrastructure optique est considéré pour lequel le critère de coût est prépondérant. Le fonctionnement des ce HPT SiGe/Si est étudié sous une longueur d'onde optique de 850 nm en exploitant des fibres optique multimode (MMF) suffisantes pour les besoins de bande passante dans un environnement de réseau domestique. Le HPT SiGe/Si est également développé dans l'objectif de permettre une intégration combiné du photorécepteur et circuit intégré monolithiquement, conduisant à des structures de type Opto-electronic Microwave Monolithically Integrated Circuit (OE-MMIC), visant à poursuivre l'intégration et la réduction des cours. Deux topologies ont été explorées principalement: 1) une topologie avec élargissement de la base et du collecteur (xBC HPT) et 2) une topologie avec élargissement des trois régions de base, émetteur et collecteur simultanément (xEBC HPT). Des variations technologies ont été réalisées et analysées en détail, à la fois en terme de couches verticales que de dessin de masque (layout). Les mesures ont démontré la validité technologique de chacune de ces approches, et permis d'isoler l'impact sur les performances statiques et dynamiques de chacune de ces couches. Une solution de type xEBC se montre ainsi préférable pour le cas de composants de petites dimensions inférieure à 50x50µm², dans la bande du GHz. Les phototransistors sont développés dans une configuration à trois terminaux (3T-HPT). Le type de polarisation de la base du HPT influe également sur la responsivité du phototransistor. Une polarisation de courant constant (CC) démontre une plus grande responsivité par rapport au cas d'une polarisation en tension ( CV). Une analyse détaillée montre aussi les différences de responsivité mesurées en continue et celles mesurées en basse fréquence à 50MHz. La connexion de base permet également de varier l'impédance de charge présentée sur celle-ci. La théorie de l'adaptation des phototransistors est rappelée. L'effet de différentes impédances de base sont étudiées par la simulation et la mesure des circuits réalisés technologiquement. L'intégration du phototransistor au sein d'un circuit élémentaire est enfin explorée. Différentes configurations de paires HPT - HBT sont étudiées, formant des circuits élémentaires. Des caractérisations expérimentales permettent de vérifier l'amélioration apportées par ces topologies par rapport au phototransistor unique. Enfin, un phototransistor SiGe en configuraiton 2T-HPT est utilisé et intégré avec succès pour la première fois au sein d'un module de type Receiving Optical Sub Assembly (ROSA) pour la mise au point d'une transmission Radio-sur-Fibre multiGigabit par seconde pour un réseau domestique
This research is focused on the study of silicon germanium based heterojunction bipolar phototransistors (SiGe HPTs) implemented in an 80GHz SiGe Bipolar process technology. It's application in a radio over fiber system for home area networks are investigated. RoF for Home area networks are envisioned to implemented with a minimal system cost. Operation at 850nm is identified as a critical parameter to achieve this goal. Low cost off the shelf optical components are readily available at this wavelength. The use of multi mode fibers (MMF) as opposed to higher cost single mode fiber (SMF) is sufficient for the bandwidth requirements in a home network environment. A monolithically integrated OE receiver chip would help in the overall reduction of the system cost by having the optical detector in the same chip with the electronic circuits. We have designed and implemented three terminal HPT (3T-HPT) structures. The two main groups of the HPT structures are: 1) HPTs with extended Base and Collector regions (xBC HPT) and 2) HPTs with extended Emitter, Base and Collector regions (xEBC HPT). Variations to improve optical coupling the though optimizations in the vertical stack and lateral size of the HPT. The measurements and characterization showed that all the structures are compatible with the process technology. The type of biasing used in the base of the HPT also influences the HPT performance. A constant current (CC) bias has higher extracted DC responsivity as compared to a constant voltage (CV) bias. The effects of the different passive base loads on the HPT responsivity are studied through simulation and measurement of fabricated circuits. The impedance presented on the base has a great influence on the HPT responsivity. The performance of an HPT as circuit component is studied using different HPT-HBT pair configurations. Tests and measurements verify that improvement in the classical transistor pair configurations are also present in the opto microwave response of the HPT-HBT pair. Finally, SiGe hpt is used in the development of a ROSA module for a radio over fiber systems for home area network

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Choudhary, Vipin. "Nondestructive testing and antenna measurements using UWB radar in industrial applications". Licentiate thesis, KTH, Teknisk informationsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291129.

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Many industries are rapidly substituting the manual test operations and move towards automated operations using modern technologies.Modern technologies such as digital cameras, sonic sensors, infrared sensors, and radar and lidar systems are used for non-destructive testingoperations. Among all the different sensors, radar systems have theability to penetrate built structures (dielectric materials), which makes them flexible and suitable for a wide range of industrial and military applications in non-destructive sensing. Such examples are the detection of damages in goods manufacturing, monitoring the health of manystructures, object detection through the wall for security purposes, etc.In particular, ultra-wide-band (UWB) radar systems are beneficial inproviding high measurement accuracy and simultaneously reduced sensitivityto passive interference (such as rain, smoke, mist etc.), immunity to external radiation and noise.The objectives of this thesis are: I) to investigate electrically small concealed structures using synthetic aperture radar (SAR), II) to determinethe complex refractive index of objects using an UWB radar system,and III) to answer to the question how we can reduce the mutual coupling (cross talk) in an UWB radar system with collocated transmitand receive antennae. In objective I, the aim is non-destructive testing of built structures, such as in concrete slab manufacturing or for use in the renovation process. In addition electrically small periodic meshes,and their orientation, could not be distinguished in conventional SAR images. The proposed polarimetric analysis method demonstrates the usefulness of the singular value decomposition (SVD) using back projection algorithm (BPA) in extracting information about shape and for classifying an electrically small object. Further in this thesis for objective II, a new method for determining the complex refractive index (or equivalently the complex relative permittivity) of objects with planar interfaces is presented. The proposed method is relatively insensitive to hardware-impairments such as frequency-dependence of antennas and analog front end. The objects can be finite in size and at a finite distance. The limits in size and distance for the method to be valid are experimentally investigated. Hence, the method is designed for industrial in-line measurements onobjects on conveyor belts. Furthermore, in the following parts of this thesis −objective III− we investigate and show how a microwave metamaterial based absorber can be used to improve the performance of aradar system for short range applications, when positioned between the transmit and receive antennas. As results, the error in estimated target distance is reduced and clutter reduction is improved.
Många branscher ersätter snabbt de manuella testoperationerna och går mot automatiserad drift med modern teknik. Modern teknik såsom digitalkameror, soniska sensorer, infraröda sensorer och radar och lidarsystem används för i icke-förstörande tester. Bland alla olika sensorerhar radarsystem förmågan att tränga igenom byggda strukturer (dielektriskmaterial), vilket gör dem flexibla och lämpliga för ett brettspektrum av industriella och militära applikationer vid icke-förstörande avkänning. Sådana exempel är upptäckt av skador vid tillverkning av varor, övervakning av hälsa hos många strukturer, detektering av objekt genom väggen av säkerhetsskäl etc. Speciellt är radarsystem med ultrabredband (UWB) fördelaktiga då de ger hög mätnoggrannhet och samtidigt minskad känslighet mot passiva störningar (såsom regn, rök,dimma etc.), och immunitet mot yttre strålning och buller. Syftet med denna avhandling är : I) att undersöka elektriskt små dolda struktur med syntetisk bländaradar (SAR), II) att bestämma komplex brytningsindex för objekt som använder UWB radarsystem, ochIII) att svar på frågan hur vi kan minska den ömsesidiga kopplingen(överhörning) i ett UWB radarsystem med sändar- och mottagarantenner nära varandra. I mål I, är målet icke-förstörande provning avbyggda struktures såsom vid tillverkning av betongplattor eller vid renovering. I tillägg kunde inte elektriskt små strukturer och deras inre struktur urskiljas i konventionella SAR-bilder. Den föreslagna polarimetriskaanalysmetoden visar på hur användbar singulärvärdesuppdelning(SVD) med bakåtprojektion (BPA) är för att få information om och för att klassificera elektriskt små objekt.Vidare i denna avhandling visas för mål II en ny metod för att bestämma komplexa brytningsindex (eller motsvarande komplexa relativa permittiviteten) hos objekt med plana ytor. Den föreslagna metoden är relativt okänslig för svagheter hos hårdvaran, såsom frekvensberoende hos antennener och analog front-end. Objekten kan vara av ändlig storlek och på ändligt avstånd. Begränsningarna i storlek och avstånd för metoden att vara giltig undersöktes experimentellt. Sålunda är metoden utformad för industriella mätningar på föremål på transportband. I de följande delarna av avhandlingen - mål III - undersöker och visar vi dessutom hur en absorbator för mikrovågor, baserad på metamaterial, kan användas för att förbättra prestanda hos ett radarsystem för korta avstånd, när absorbatorn placeras mellan sändar- och mottagantenner. Resultatet blir att felet i det bestämda avståndet till målet minskar och undertryckning av klotter ökar.

QC 20210309

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Ahmed, Amr. "Design And Optimization Of Uwb Antenna For Air Coupled Gpr Applications". ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/262.

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This thesis presents a novel antenna structure that satisfies the challenging requirements of an air coupled high speed ground penetrating radar (GPR). The desired GPR system is to achieve high spatial resolution and accurate inspection results while scanning at relatively high speed for highway pavement and bridge deck inspection. This work utilizes the Ultra Wide Band (UWB) antenna design to achieve both physical and electrical requirements imposed. The design procedure starts with a short survey to discuss typical UWB antennas used for GPR applications, and various tradeoffs of each type specifically when used for Air Coupled GPR applications. Our structure anatomy is presented, followed by a theory introduction that mainly focuses on achieving good impedance matching throughout the proposed antenna structure. A proof-of-concept MATLAB model is created to evaluate the preliminary physical dimensions that can achieve minimum reflections at antenna's feed point. These dimensions are then used in SolidWorks to create a 3D model that is imported later in HFSS to obtain accurate electromagnetic characteristics. Furthermore, fine tunings are performed to the antenna structure to optimize both gain and impedance matching. The SolidWorks 3-D structural model is finally used for antenna fabrication. The measurements recorded from the field experiments using the prototypes manufactured are compared to the simulation results confirming our initial findings. Both measurements and simulation results demonstrated very small reflection loss across the 700 MHz ~ 6 GHz frequency band with a very high directed gain and radiation efficiency.

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12

Salmani, Zeeshan. "Design and Implementation of Broad Band and Narrow Band Antennas and Their Applications". Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc84270/.

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The thesis deals with the design and implementation of broadband and narrowband antennas and their applications in practical environment. In this thesis, a new concept for designing the UWB antenna is proposed based on the CRLH metamaterials and this UWB antenna covers a frequency range from 2.45 GHz to 11.6 GHz. Based on the design of the UWB antenna, another antenna is developed that can cover a very wide bandwidth i.e from 0.66 GHz to 120 GHz. This antenna can not only be used for UWB applications but also for other communication systems working below the UWB spectrum such as GSM, GPS, PCS and Bluetooth. The proposed antenna covering the bandwidth from 0.66 GHz to 120 GHz is by far the largest bandwidth antenna developed based on metamaterials. Wide band antennas are not preferred for sensing purpose as it is difficult to differentiate the received signals. A multiband antenna which can be used as a strain sensor for structural health monitoring is proposed. The idea is to correlate the strain applied along the length or width with the multiple resonant frequencies. This gives the advantage of detecting the strain applied along any direction (either length or width), thus increasing the sensing accuracy. Design and application of a narrow-band antenna as a temperature sensor is also presented. This sensor can be used to detect very high temperature changes (>10000C). This sensor does not require a battery, can be probed wirelessly, simple and can be easily fabricated, can withstand harsh environmental conditions.

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13

Nikolaou, Symeon. "Design and implementation of compact reconfigurable antennas for UWB and WLAN applications". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/24802.

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Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Manos M. Tentzeris; Committee Co-Chair: John Papapolymerou; Committee Member: Andrew F. Peterson; Committee Member: Chang-Ho Lee; Committee Member: John D. Cressler; Committee Member: Joy Laskar.

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Barrett, Luke. "UWB radiolocation technology: Applications in relative positioning algorithms for autonomous aerial vehicles". Thesis, Barrett, Luke (2018) UWB radiolocation technology: Applications in relative positioning algorithms for autonomous aerial vehicles. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/41905/.

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This report presents methods and technologies used to investigate the use of commercially available Ultra-Wide Band (UWB) radiolocation technology in the positioning of autonomous vehicles. UWB radio has unique transmission characteristics which make pico-second resolution timing possible, a requirement for centimetre accuracy in positioning applications. Firstly, an investigation into the performance capabilities of UWB positioning infrastructure was undertaken, followed by the development of relative positioning algorithms utilising a relative and decentralised control approach. These algorithms are based on feedback provided by radiolocation data in combination with sensor fusion elements, including inertial (accelerometers), optical (optical flow sensors) and absolute ranging sensors such as Light Detection and Ranging (LIDAR). Performance of the UWB infrastructure was determined utilising static and dynamic measurement techniques to verify overall positioning accuracy and statistical characteristics, with respect to two different ranging algorithms, Time Difference of Arrival (TDOA) and Two Way Ranging (TWR). Data collected from an array of static collection points has shown, in the recommended infrastructure configuration, that commercially available UWB technology has a positional accuracy with an average offset from the real coordinate system of 7.30-15.28%. Logic-based tests using statistical inputs indicate the TDOA algorithm succeeds in more accurate positioning in 79.63%, 58.33% and 85.19% of test cases across twenty-seven points in three vertical planes respectively. Data collected from autonomous flight-path algorithms has provided practical insight into applications of the technology and its dynamic capabilities. Results demonstrate that in a high radio interference environment, performance of the UWB positioning system and drone achieve a 0.11% and 1.23% error on average from the programmed flight path gradient for TDOA and TWR respectively. The results of this investigation suggest that the technology is ready and capable of being implemented on real-world systems, with the recommendation that the technology be coupled with sensor fusion elements in relative positioning applications.

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Dubouloz, Samuel. "Développement d'architectures avancées pour communications ultra large bande (UWB) dans des applications bas débit". Phd thesis, Télécom ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00003907.

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Nombre d'applications nécessitent un lien de communication sans fil présentant une faible consommation électrique, sans requérir de débits élevés. La technologie basée sur la transmission de signaux impulsionnels UWB dispose de bonnes propriétés intrinsèques permettant non seulement d'envisager la mise en œuvre de solutions peu complexes au niveau de l'émetteur-récepteur, mais aussi d'exploiter à des fins de radiolocalisation la résolution temporelle inhérente à la largeur de bande disponible. Cette technologie a d'ailleurs été plébiscitée au sein du groupe IEEE 802.15.4a qui a été chargé de définir une couche physique alternative pour les WPAN bas débit. C'est dans ce contexte de recherche technologique et de normalisation que s'inscrivent ces travaux de thèse, avec pour objectif la définition d'une architecture de récepteur consommant peu, et compatible avec la norme en cours d'élaboration. En premier lieu, nous caractérisons les signaux UWB et développons un modèle d'impulsion prenant en compte les principaux paramètres de la couche physique intervenant dans la puissance rayonnée (largeur de bande, densité spectrale, fréquence de répétition des impulsions, etc.). Nous étudions ensuite l'influence du canal de propagation et modélisons de manière statistique plusieurs grandeurs nécessaires à l'établissement d'un bilan de liaison réaliste (distribution des amplitudes reçues, répartition de l'énergie, etc.). À la lumière de ces études, nous explorons et comparons différentes architectures de réception (performance, complexité, robustesse aux trajets multiples, etc). Enfin, la solution retenue, comprenant également un algorithme de synchronisation, est présentée en détails.

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Zang, Yuzhang. "UWB Motion and Micro-Gesture Detection -Applications to interactive electronic gaming and remote sensing". Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/1241.

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The ultra-wideband (UWB) technology has a vast unlicensed frequency spectrum, which can support precise indoor positioning in orders of centimeters. The features of UWB signals can be utilized for variety of applications. In this project first we present an empirical channel models to analyze the localization accuracy of the UWB technology for interactive electronic gaming (Ping-Pong) in Line-of-Sight (LOS) and Obstructed LOS (OLOS) scenarios. Then we introduce a new concept that we refer to as micro-gesture detection to handle the more refined motions of the hand, such as rotation, while one antenna is held by the user using features of UWB signal. We use four specific features of the UWB signals: time of arrival, power of the first peak, total power, and the Root-Mean Square (RMS) of the delay spread, for this purpose. As the hand rotates the position of the antenna in the hand and the external antenna changes from LOS to OLOS. We demonstrate that features of the UWB signals are more useful than the RSS signal of the Wi-Fi to detect this class of micro-gestures. We foresee this micro-gesture detection capabilities become helpful for the people with limited ability or visually impaired for implementation of simplified sign language to communication with electronic devices located away from a person. We compare gesture detection using multiple features of the UWB signal with traditional gesture detection using the received signal strength (RSS) of the Wi-Fi signal.

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Condict, Nahlah. "EXPERIMENTAL ANALYSIS OF MULTI-PURPOSE UWB RF SYSTEM FOR AD-HOC RADAR SENSOR NETWORK APPLICATIONS". Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1533915320524546.

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18

Sonkki, M. (Marko). "Wideband and multi-element antennas for mobile applications". Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526201085.

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Abstract This dissertation presents wideband and multi-element antennas for mobile applications. It is divided into the following main parts: modal theory, wideband antennas, multi-element antennas, and wideband multi-element antennas. The radiating fields are first studied in terms of spherical scalar and vector modes, and it is shown how these modes correlate with the characteristic current modes on a planar mobile ground plane. The theory part shows how it is possible to excite the same modes on a conventional sphere and a rectangular planar mobile ground plane. The theory refers to the novel wideband antenna structures presented in this dissertation, in terms of current and radiating modes. After studying the modes, the dissertation shows how to excite a radiating antenna mode within a wide frequency bandwidth. To gain this, two main approaches are taken. First, a quasi-complementary antenna (QCA) structure with an electric conductor and magnetic slot is presented, and its characteristics are studied. A QCA UWB antenna, and a QCA element excited with a monopole or a dipole, is presented. The QCA structure compensates for the imaginary part of the input impedance on wide frequency bandwidth, when, at the same time, the fundamental mode is excited to ensure good radiating properties. The second approach uses a symmetrical feeding with two antenna elements to gain a wide frequency bandwidth, the relative -6 dB impedance bandwidth between 37.5–80%. When a field is symmetrically coupled to the conducting ground plane, the excitation avoids the awakening of higher order modes which might disturb the performance of the antenna. It is also shown, by using multiple feeding elements, that the excitation of orthogonal higher order modes on a small radiating ground plane is possible. As the modes are orthogonal to each other, they present a very low correlation. By using this kind of approach, radiation pattern diversity can be obtained in mobile applications within a small volume. On the other hand, when combining two QCA elements to a one multi-element antenna structure, a wideband diversity antenna with an 87.5% relative -6 dB impedance bandwidth, and a wideband MIMO antenna with a 95.0% relative -6 dB impedance bandwidth, are presented with excellent radiation and correlation properties. Also mutual coupling is need to be counted when multi-element antennas are designed. When designing an efficient radiator, it is important to consider an antenna feeding in terms of wideband impedance matching and wideband baluns, not to spoil the antenna performance. The efficient antenna structures and feeding mechanisms are obtained by using commercial 3D electromagnetic simulators to find the desired wideband antenna characteristics. Prototype antennas are measured in most of the presented structures to show their functionality in real. In general, the dissertation presents wideband antenna structures with radiating antenna modes excited on a planar conducting ground plane. The idea is to find structures and feeding mechanisms to excite the fundamental mode, or a certain radiating antenna mode, at a wide frequency bandwidth, by avoiding the excitation of higher order modes which might disturb the antenna performance. It is also shown that, by using multiple feeding elements, it is possible to excite higher order modes on a small antenna
Tiivistelmä Väitöskirjassa esitetään uusia laajakaistaisia ja monielementtiantenneja matkaviestimiin. Väitöskirja koostuu neljästä pääalueesta: pintavirtojen muototeoria, laajakaistaiset antennit, monielementtiantennit sekä laajakaistaiset monielementtiantennit. Teoriaosassa säteilykenttiä on aluksi tutkittu pallon pinnalla sekä skalaaripotentiaaleina että pintavirtavektoreina, jonka jälkeen niitä on verrattu mobiilin laitteen maatason ominaispintavirtojen synnyttämiin säteilykenttiin. Teoriaosassa osoitetaan, että pallon pinnalla sekä tasomaisella suorakaiteen muotoisella pinnalla on mahdollista herättää samat säteilykentät. Myöhemmin väitöskirjassa esitettävien uudenlaisten antennirakenteiden ominaisuuksia verrataan teoriaosassa esitettyihin pintavirtoihin ja säteilykenttiin. Teoriaosuuden jälkeen osoitetaan miten säteilevä sähkömagneettinen kenttä saadaan herätettyä laajalla taajuusalueella. Tähän on otettu kaksi eri lähestymistapaa, joista ensimmäisessä esitellään ja tutkitaan kvasikomplementaarista antennirakennetta (QCA). Kvasikomplementaarisessa antennirakenteessa sisääntuloimpedanssin imaginaariosa kompensoidaan yhdistämällä sähköinen johde ja magneettinen rako samaan antenniin. Samanaikaisesti perusmuoto herätetään laajalla taajuusalueella, jolla varmistetaan antennin hyvät säteilyominaisuudet koko toimintataajuusalueella. Toisessa lähestymistavassa käytetään kahta symmetrisesti asetettua antennielementtiä, joita syötetään symmetrisesti samalla amplitudilla ja vaiheella. Kun sähkömagneettinen kenttä herätetään symmetrisesti, korkeamman kertaluvun muotojen herättäminen voidaan välttää laajalla taajuusalueella. Symmetrisesti syötetyillä antennirakenteilla saavutettu -6 dB suhteellinen impedanssikaistanleveys on 37.5–80 %. Useita syöttöelementtejä käytettäessä voidaan mobiilin laitteen maatasossa herättää yhdellä pistetaajuudella monta toisistaan riippumatonta säteilykenttää. Koska herätetyt kentät ovat toisistaan riippumattomia, on niiden välinen korrelaatio myös pieni. Kyseisellä rakenteella on mahdollista toteuttaa säteilykuviodiversiteetti erittäin pienessä tilassa, kuten matkapuhelimessa. Toisaalta, kun yhdistetään kaksi QCA-elementtiä yhdeksi monielementtiratkaisuksi, voidaan toteuttaa laajakaistainen diversiteettiantenni, jonka suhteellinen -6 dB impedanssikaistanleveys on 87.5 %. Vastaavasti kahdella laajakaistaisella QCA-elementillä toteutetulla MIMO-ratkaisulla päästään 95 % suhteelliseen -6 dB impedanssikaistanleveyteen. Molemmilla ratkaisuilla on erittäin hyvät säteilyominaisuudet sekä alhainen korrelaatio ja pieni keskinäiskytkentä antennielementtien välillä. Suunniteltaessa toimivaa laajakaistaista antennirakennetta, on tärkeää ottaa huomioon antennisyötön impedanssisovitus, jotta antennin suorituskyky ei heikkenisi. Lisäksi balansoidussa rakenteissa tulee olla laajakaistainen baluni, jolla vältetään säteilykuvion vääristyminen. Väitöskirjan syöttöratkaisuissa on käytetty kaupallisia sähkömagneettisia simulaattoreita, joilla antennirakenne voidaan mallintaa kolmiulotteisesti, ja joilla laajakaistainen syöttö saadaan optimoitua haluttuun antenniin. Suurin osa esitellyistä antennirakenteista on simulointien lisäksi myös mitattu, jolloin niiden toimivuus käytännössä pystytään todentamaan rakentamalla prototyyppiantenni. Yleisesti väitöskirjassa esitellään tasomaisia antenniratkaisuja johtavassa maatasossa, joissa säteilevät pintavirrat herätetään mahdollisimman laajalla taajuusalueella. Ideana on löytää laajakaistaisia antenni- ja syöttörakenteita, joilla saadaan herätettyä perusmuoto tai jokin muu haluttu muoto. Ajatuksena on välttää korkeamman kertaluvun muotojen herättäminen, jotka voivat pilata antennin suorituskyvyn. Väitöskirjassa osoitetaan myös, että pienikokoisella antennilla on mahdollista herättää korkeamman kertaluvun muotoja pistetaajuudella käyttämällä useita heräte-elementtejä

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Pardiñas, Mir Jorge Arturo. "Contribution à l'étude de la détection des signaux UWB. Etude et implémentation d'un récepteur ad hoc multicapteurs. Applications indoor de localisation". Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00814663.

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Cette thèse s'inscrit dans le projet de communication à proximité aux départements Electronique et Physique et Communications, Images et Traitement de l'Information de l'Institut Télécom Sud Paris. Le projet comporte la mise au point d'un récepteur basé sur une méthode de détection pseudo-cohérente des signaux Ultra Large Bande à double impulsion (TR-UWB), méthode désignée par Time Delayed Sampling and Correlation (TDSC). La première partie de ce document comporte la réalisation d'une plate-forme modulaire de communication UWB basée sur le système de détection TDSC. Cette plate-forme comporte une puce CMOS 0.35μm conçue précédemment au laboratoire EPH. Elle offre la possibilité d'enregistrer des signaux TR-UWB réels et de réaliser des tests de fonctionnement. La deuxième partie est une étude approfondie du récepteur utilisant la méthode TDSC. La détection des signaux UWB et la procédure de synchronisation sont évalués en utilisant les signaux réels acquis à partir de la plate-forme. Un ensemble de tests ont été menés avec des signaux en bande de base et des signaux transposés en fréquence, dans les deux cas en transmission sur câble puis par radio. Les résultats ont permis de valider la détection et le principe de la synchronisation. La troisième partie est une proposition d'estimation de la distance entre deux dispositifs d'un réseau radio UWB utilisant un récepteur TDSC, pour une localisation en intérieur. L'étude fait la synthèse de plusieurs propositions et expérimentations et conduit à la définition des meilleurs critères pour une mesure du temps d'arrivée (TOA) et son implémentation pratique sur un récepteur TDSC

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20

Pepe, Domenico. "Deep sub-micron RF-CMOS design and applications of modern UWB and millimeter-wave wireless transceivers". Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13815/document.

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L'activité de recherche scientifique effectuée dans le cadre de mon doctorat de sciences s'est déroulée dans le secteur de la conception de circuits intégrés radiofréquences pour des systèmes ultra-wideband (UWB) et aux ondes millimétriques, et s'est articulée comme suit: (i) circuits intégrés radiofréquences pour émetteur-récepteurbasse puissance pour réseaux locaux wireless; (ii) radar UWB complètement intégré pour la surveillance cardio-pulmonaire en technologie 90nm CMOS; (iii) amplificateurs faible bruit (LNA) à 60 GHz en technologie standard 65nm CMOS
The research activity carried out during this PhD consists on the design of radio- frequency integrated circuits, for ultra-wideband (UWB) and millimeter-wave sys- tems, and covers the following topics: (i) radio-frequency integrated circuits for low-power transceivers for wireless local networks; (ii) fully integrated UWB radar for cardio-pulmonary monitoring in 90nm CMOS technology; (iii) 60-GHz low noise amplifer (LNA) in 65nm CMOS technology

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Chirala, Mohan Krishna. "Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2069.

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Shen, Jue. "Interactive RFID for Industrial and Healthcare Applications". Doctoral thesis, KTH, Industriell och Medicinsk Elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174380.

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This thesis introduces the circuit and system design of interactive Radio-Frequency Identification (RFID) for Internet of Things (IoT) applications. IoT has the vision of connectivity for anything, at anytime and anywhere. One of the most important characteristics of IoT is the automatic and massive interaction of real physical world (things and human) with the virtual Internet world.RFID tags integrated with sensors have been considered as one suitable technology for realizing the interaction. However, while it is important to have RFID tags with sensors as the input interaction, it is also important to have RFID tags with displays as the output interaction.Display interfaces vary based on the information and application scenarios. On one side, remote and centralized display interface is more suitable for scenarios such as monitoring and localization. On the other side, tag level display interface is more suitable for scenarios such as object identification and online to offline propagation. For tag level display, though a substantial number of researches have focused on introducing sensing functionalities to low power Ultra-High Frequency (UHF) RFID tags, few works address UHF RFID tags with display interfaces. Power consumption and integration with display of rigid substrate are two main challenges.With the recent emerging of Electronic Paper Display (EPD) technologies, it becomes possible to overcome the two challenges. EPD resembles ordinary ink on paper by characteristics of substrate flexibility, pattern printability and material bi-stability. Average power consumption of display is significantly reduced due to bi-stability, the ability to hold color for certain periods without power supplies. Among different EPD types, Electrochromic (EC) display shows advantage of low driving voltage compatible to chip supply voltage.Therefore this thesis designs a low power UHF RFID tag integrated in 180 nm CMOS process with inkjet-printed EC polyimide display. For applications where refresh rate is ultra-low (such as electronic label in retailing and warehouse), the wireless display tag is passive and supplied by the energy harvested from UHF RF wave. For applications where refresh rate is not ultra-low (such as object identification label in mass customized manufacturing), the wireless display tag is semi-passive and supplied by soft battery. It works at low average power consumption and with out-of-battery alert. For remote and centralized display, the limitations of uplink (from tags to reader) capacity and massive-tag information feedback in IoT scenarios is the main challenge. Compared to conventional UHF RFID backscattering whose data rate is limited within hundreds of kb/s, Ultra-wideband (UWB) transmission have been verified with the performance of Mb/s data rate with several tens of pJ/pulse energy consumption.Therefore, a circuit prototype of UHF/UWB RFID tag replacing UHF backscattering with UWB transmitter is implemented. It also consists of Analog-to-Digital Converter (ADC) and Electrocardiogram (ECG) electrodes for healthcare applications of real-time remote monitoring of multiple patients ECG signals. The ECG electrodes are fabricated on paper substrate by inkjet printing to improve patient comfort. Key contribution of the thesis includes: 1) the power management scheme and circuit design of passive UHF/UWB RFID display tag. The tag sensitivity (the input RF power) is -10.5 dBm for EC display driving, comparable to the performance of conventional passive UHF RFID tags without display functions, and -18.5 dBm for UWB transmission, comparable to the state-of-the-art performance of passive UHF RFID tag. 2) communication flow and circuit design of UHF/UWB RFID tag with ECG sensing. The optimum system throughout is 400 tags/second with 1.5 KHz ECG sampling rate and 10 Mb/s UWB pulse rate.

QC 20151012

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Zhao, Yan. "Numerical Modelling of Material Dispersions for UWB and Metamaterial Applications Using the Finnite-Difference Time-Domain Method". Thesis, Queen Mary, University of London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498165.

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Addepalli, T., A. Desai, Issa T. Elfergani, N. Anveshkumar, J. Kulkarni, C. Zebiri, J. Rodriguez i Raed A. Abd-Alhameed. "8-Port Semi-Circular Arc MIMO Antenna with an Inverted L-Strip Loaded Connected Ground for UWB Applications". MDPI, 2021. http://hdl.handle.net/10454/18536.

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yes
Multiple-input multiple-output (MIMO) antennas with four and eight elements having connected grounds are designed for ultra-wideband applications. Careful optimization of the lines connecting the grounds leads to reduced mutual coupling amongst the radiating patches. The proposed antenna has a modified substrate geometry and comprises a circular arc-shaped conductive element on the top with the modified ground plane geometry. Polarization diversity and isolation are achieved by replicating the elements orthogonally forming a plus shape antenna structure. The modified ground plane consists of an inverted L strip and semi ellipse slot over the partial ground that helps the antenna in achieving effective wide bandwidth spanning from (117.91%) 2.84–11 GHz. Both 4/8-port antenna achieves a size of 0.61 λ × 0.61 λ mm2 (lowest frequency) where 4-port antenna is printed on FR4 substrate. The 4-port UWB MIMO antenna attains wide impedance bandwidth, Omni-directional pattern, isolation >15 dB, ECC 4.5 dB making the MIMO antenna suitable for portable UWB applications. Four element antenna structure is further extended to 8-element configuration with the connected ground where the decent value of IBW, isolation, and ECC is achieved.

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Ripoche, Olivier. "Miniaturisation d'antennes en bande VHF pour applications spatiales". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-00938676.

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Le développement de l'électronique embarquée et miniaturisée est pleinement d'actualité de nos jours, dans les domaines tels que l'armement, la médecine, et les télécommunications. La miniaturisation des antennes large-bande, opérationnelles sur plus d'une décade, présentent un défi particulier. Ces travaux de thèse proposent de travailler sur la miniaturisation d'une antenne spirale, afin d'en réduire l'encombrement, à savoir son diamètre, tout en conservant au mieux ses caractéristiques de rayonnement et polarisation intrinsèques. Cette recherche sera appliquée à la bande des Très hautes Fréquence (Very High Frequencies - VHF), allant de 30MHz (λ = 10m) à 300MHz (λ = 1m). La géométrie inédite proposée consiste à associer à une antenne spirale un ensemble d'anneaux résonnants, dont le diamètre n'excède pas celui de la spirale, et permettant de diminuer la fréquence basse de fonctionnement. Pour un ensemble de cinq anneaux associé à la spirale, la réduction de la fréquence basse de fonctionnement est de plus de 30%. Pour deux antennes spirales de même fréquence basse de fonctionnement, l'antenne miniaturisée a donc un diamètre réduit de 30%, soit une surface réduite de 50%. Les performances de l'état de l'art d'après lesquelles les réductions sur le diamètre des antennes spirales n'excèdent pas 15% sont donc dépassées. De plus, d'après cet état de l'art, les méthodes de réduction appliquées aux antennes large bande dégradent en général le gain et l'axial ratio dans les bandes basses de fréquences de fonctionnement. La méthode proposée permet de conserver l'efficacité de l'antenne, voire de l'augmenter, dans les fréquences proches de la fréquence basse de fonctionnement. Le rayonnement de l'antenne spirale miniaturisée dans la bande passante de l'antenne sans anneaux n'est pour autant pas modifiée. Ces résultats très encourageant ont été confirmés par la mesure d'antennes spirales miniaturisées, réalisées pour un diamètre de 8cm et de 1m : une réduction de 30% du diamètre sans dégradation du rayonnement a été observée. Les mesures ont par ailleurs donné lieu à l'étude de la réalisation d'une antenne en bande VHF, avec pour implication les problématiques de réalisation (masse, encombrement, résistance mécanique) et de mesure (isolation, effets parasites en VHF avec une longueur d'onde de 4m).

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Elfergani, Issa T. "Investigation, design and implementation of frequency tuneable antennas for mobile handset and UWB applications : simulation and measurement of tunable antennas for handheld mobile handsets and UWB system, investigations of frequency tuneable range, antenna radiation performance and antenna design optimisation using parametric studies". Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/13761.

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Park, Yunseo. "Direct Conversion RF Front-End Implementation for Ultra-Wideband (UWB) and GSM/WCDMA Dual-Band Applications in Silicon-Based Technologies". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7563.

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This dissertation focuses on wideband circuit design and implementation issues up to 10GHz based on the direct conversion architecture in the CMOS and SiGe BiCMOS technologies. The dissertation consists of two parts: One, implementation of a RF front-end receiver for an ultra-wideband system and, two, implementation of a local oscillation (LO) signal for a GSM/WCDMA multiband application. For emerging ultra-wideband (UWB) applications, the key active components in the RF front-end receiver were designed and implemented in 0.18um SiGe BiCMOS process. The design of LNA, which is the critical circuit block for both systems, was analyzed in terms of noise, linearity and group delay variation over an extemely wide bandwidth. Measurements are demonstrated for an energy-thrifty UWB receiver based on an MB-OFDM system covering the full FCC-allowed UWB frequency range. For multiband applications such as a GSM/WCDMA dual-band application, the design of wideband VCO and various frequency generation blocks are investigated as alternatives for implementation of direct conversion architecture. In order to reduce DC-offset and LO pulling phenomena that degrade performance in a typical direct conversion scheme, an innovative fractional LO signal generator was implemented in a standard CMOS process. A simple analysis is provided for the loop dynamics and operating range of the design as well as for the measured results of the factional LO signal generator.

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28

Zaikou, Yahor [Verfasser], Reiner [Akademischer Betreuer] Thomä, Dusan Gutachter] Kocur i Uwe [Gutachter] [Pliquett. "Microwave UWB sensors for measurements under non-stationary conditions : detection of human being beneath rubble for rescue applications / Yahor Zaikou ; Gutachter: Dusan Kocur, Uwe Pliquett ; Betreuer: Reiner Thomä". Ilmenau : TU Ilmenau, 2018. http://d-nb.info/1178129004/34.

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Ghavami, Navid. "Ultra-wideband imaging techniques for medical applications". Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6f590d26-ee7c-41d7-a89b-393c864c9d82.

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Ultra-wideband (UWB) radio techniques have long promised good contrast and high resolution for imaging human tissue and tumours; however, to date, this promise has not entirely been realised. In recent years, microwave imaging has been recognised as a promising non-ionising and non-invasive alternative screening technology, gaining its applicability to breast cancer by the significant contrast in the dielectric properties at microwave frequencies of normal and malignant tissues. This thesis deals with the development of two novel imaging methods based on UWB microwave signals. First, the mode-matching (MM) Bessel-functions-based algorithm, which enables the identification of the presence and location of significant scatterers inside cylindrically-shaped objects is introduced. Next, with the aim of investigating more general 3D problems, the Huygens principle (HP) based procedure is presented. Using HP to forward propagate the waves removes the need to apply matrix generation/inversion. Moreover, HP method provides better performance when compared to conventional time-domain approaches; specifically, the signal to clutter ratio reaches 8 dB, which matches the best figures that have been published. In addition to their simplicity, the two proposed methodologies permit the capture of a minimum dielectric contrast of 1:2, the extent to which different tissues, or differing conditions of tissues, can be discriminated in the final image. Moreover, UWB allows all the information in the frequency domain to be utilised, by combining information gathered from the individual frequencies to construct a consistent image with a resolution of approximately one quarter of the shortest wavelength in the dielectric medium. The power levels used and the specific absorption rates are well within safety limits, while the bandwidths satisfy the UWB definition of being at least 20% of the centre frequencies. It follows that the methodologies permit the detection and location of significant scatterers inside a volume. Validation of the techniques through both simulations and measurements have been performed and presented, illustrating the effectiveness of the methods.

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Waqar, Adnan. "Enhancing the capabilities of electronic performance tracking system for applications in sports". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2022. https://ro.ecu.edu.au/theses/2562.

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The success of electronic technologies has sparked interest in sports amongst coaches, athletes and sports scientists. Consequently, the sporting world has witnessed a rapid rise in sports technologies in recent years. In sports, technologies can assist in a variety of ways, ranging from winner selection to athlete injury prevention. In recent years, wearable technologies have become popular in sports. Wearable microtechnology devices, commonly known as electronic performance tracking system (EPTS) in sports, can be used to monitor and improve an athlete's performance. EPTSs can also play an important role in injury prevention. This thesis investigates the performance of wearable EPTSs and presents solutions to improve the accuracy of EPTSs in sports. For an EPTS to capture and accurately quantify important athlete-related parameters, such as speed, distance covered, number and intensity of sprints, change of direction (COD), and positioning and movement, data is of vital importance. Whilst satellite-based positioning systems require a relatively short setup time, their accuracy and reliability are often low. Wearable inertial sensors may be able to track an athlete's movements, but they can also be noisy and their error accumulates over time. Consequently, designing an accurate and wearable EPTS is a complex task and requires critical investigation. This featured as the key motivation for this research, whose findings are presented in this thesis. In this thesis, a new ultra-wide band (UWB)-based positioning system is proposed to increase the accuracy of an EPTS in indoor sports. A close analysis of real-world experiments is presented, and limitations associated with the UWB-based positioning systems are highlighted. In forming an economical hardware solution, geometric and machine learning algorithms are introduced. The accuracy of the developed solution is compared against conventional positioning systems. To mitigate errors in UWB-based indoor positioning systems, a range error reduction technique is introduced. The optimal hardware setup and complexity for implementing the proposed positioning solution are also discussed. In order to track an athlete's movements using real-world data, a multi-sensor data fusion approach is introduced for measuring/tracking athletes' change of direction (COD) detection and quantification. This COD data is then used to reduce divergence errors incurred in state estimation-based particle filter algorithms. The developed solution achieves significant improvements as compared to existing techniques. Overall, the proposed EPTS solution offers higher accuracy in tracking an athlete's position and movement data. Further, the proposed solution enables the use of EPTS in indoor environments.

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Lopez-Castellanos, Victor. "Ultrawideband Time Domain Radar for Time Reversal Applications". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1301040987.

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Guardiola, Garcia Marta. "Multi-antenna multi-frequency microwave imaging systems for biomedical applications". Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/134967.

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Medical imaging refers to several different technologies that are used to view the human body in order to diagnose, monitor, or treat medical conditions. Each type of technology gives different information about the area of the body being studied depending on the radiation used to illuminate de body. Nowadays there are still several lesions that cannot be detected with the current methods in a curable stage of the disease. Moreover they present some drawbacks that limit its use, such as health risk, high price, patient discomfort, etc. In the last decades, active microwave imaging systems are being considered for the internal inspection of light-opaque materials thanks to its capacity to penetrate and differentiate their constituents based on the contrast in dielectric properties with a sub-centimeter resolution. Moreover, they are safe, relatively low-cost and portable. Driven by the promising precedents of microwaves in other fields, an active electromagnetic research branch was focused to medical microwave imaging. The potential in breast cancer detection, or even in the more challenging brain stroke detection application, were recently identified. Both applications will be treated in this Thesis. Intensive research in tomographic methods is now devoted to develop quantitative iterative algorithms based on optimizing schemes. These algorithms face a number of problems when dealing with experimental data due to noise, multi-path or modeling inaccuracies. Primarily focused in robustness, the tomographic algorithm developed and assessed in this thesis proposes a non-iterative and non-quantitative implementation based on a modified Born method. Taking as a reference the efficient, real-time and robust 2D circular tomographic method developed in our department in the late 80s, this thesis proposes a novel implementation providing an update to the current state-of-the-art. The two main contributions of this work are the 3D formulation and the multi-frequency extension, leading to the so-called Magnitude Combined (MC) Tomographic algorithm. First of all, 2D algorithms were only applicable to the reconstruction of objects that can be assumed uniform in the third dimension, such as forearms. For the rest of the cases, a 3D algorithm was required. Secondly, multi-frequency information tends to stabilize the reconstruction removing the frequency selective artifacts while maintaining the resolution of the higher frequency of the band. This thesis covers the formulation of the MC tomographic algorithm and its assessment with medically relevant scenarios in the framework of breast cancer and brain stroke detection. In the numerical validation, realistic models from magnetic resonances performed to real patients have been used. These models are currently the most realistic ones available to the scientific community. Special attention is devoted to the experimental validation, which constitutes the main challenge of the microwave imaging systems. For this reason, breast phantoms using mixtures of chemicals to mimic the dielectric properties of real tissues have been manufactured and an acquisition system to measure these phantoms has been created. The results show that the proposed algorithm is able to provide robust images of medically realistic scenarios and detect a malignant breast lesion and a brain hemorrhage, both at an initial stage.

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Lepage, Anne Claire. "Analyse et optimisation d'antennes tridimensionnelles : applications à la conception d'antennes compactes intégrées dans un système de communication ultra-large bande". Phd thesis, Télécom ParisTech, 2005. http://pastel.archives-ouvertes.fr/pastel-00002238.

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Depuis plusieurs années, le domaine des télécommunications et des nouvelles technologies connaît un véritable essor. On assiste aujourd'hui à un engouement sans précédent du grand public pour les applications de communication multimédia (données, voix, photos, vidéos) et la demande est de plus en plus forte pour un transfert à haut débit entre des équipements communicants mobiles et à encombrement réduit. De plus, que le mode d'utilisation soit nomade ou sédentaire, les technologies radio sans fils (Bluetooth, WiFi, GPRS, UMTS, WiMax) connaissent un grand succès. Pour répondre à ces besoins croissants de communication sans fils à haut débit, les futures générations d'équipements vont faire appel à des antennes de plus en plus performantes. Celles-ci devront fonctionner sur plusieurs bandes de fréquences ou sur une large bande. Mais elles devront aussi, pour des raisons pratiques et esthétiques, être intégrées aux systèmes radio, ce qui requiert la mise au point de structures compactes, discrètes et n'ayant pas de problèmes de compatibilité électromagnétique avec les circuits électroniques environnants. Pour répondre à ces différents objectifs, nous avons axé notre recherche sur les antennes tridimensionnelles qui offrent un grand nombre de degrés de liberté. Mais ces structures sont souvent complexes car elles comportent de nombreux paramètres. Afin de mieux les appréhender, nous proposons dans cette thèse d'élaborer une démarche de conception de ces antennes. Ainsi, nous commençons par l'étude systématique d'une antenne canonique constituée d'un dipôle placé à proximité d'une cavité métallique rectangulaire. L'effet des différents paramètres est analysé afin de mettre en évidence l'importance relative de chacun d'entre eux et de proposer ainsi une démarche de conception pour optimiser la bande passante et le rayonnement de l'antenne. Dans un deuxième temps, nous présentons la conception d'une antenne tridimensionnelle compacte, large bande et directive, l'antenne "sonde en F et triangle", qui offre l'avantage de présenter un diagramme de rayonnement stable en fréquence. Puis, fort de l'expérience acquise sur l'antenne dipôle, nous procédons de nouveau à une étude de l'influence sur l'impédance des différents paramètres de cette antenne complexe. Celle-ci permet d'élaborer une méthodologie de conception simple, rapide, efficace et générale. Nous pouvons ainsi optimiser l'antenne "sonde en F et triangle" et atteindre une bande passante en adaptation comprise entre 3.1 et 6.1 GHz. Le diagramme de rayonnement de cette antenne est stable sur la bande passante et le gain moyen de cette antenne est de 6 dB. Une caractérisation dans le domaine temporel est ensuite proposée afin de connaître le comportement de l'antenne dans une communication UWB. Enfin, l'antenne "sonde en F et triangle" est mise en cavité afin d'étudier ses propriétés lors de l'intégration dans un système radio. Des analogies et différences entre cette antenne complexe et le système {dipôle et cavité} sont également mises en évidence.

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Santhanam, Manisundaram. "UWB technology and its application". Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Data- och elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-16970.

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Despite the fact ultra-wideband (UWB) technology has been around for over 30 years, there is a newfound excitement about its potential for communications. With the advantageous qualities of multipath immunity and low power spectral density, researchers are examining fundamental questions about UWB communication systems. Majorly the whole report gives a complete picture about properties of UWB signal and its advantages and disadvantages, generation of the UWB pulse using various techniques, Modulation scheme, Test bed, applications, UWB regulations. The report mainly concerns with the survey about various techniques and also its comparison of generating UWB pulses using various components. There is a general description on various modulation and demodulation scheme that are relevant to UWB technology and its various applications concerning different fields. This report clearly explains how UWB is far better than RFID and difference between active and passive RFID and its communication protocol, message format. Clear explanation about advantage of higher operating frequencies and low power spectral density. Properties of UWB pulse gives clear idea why we go for UWB and in near future lot of applications will discover. Generation of UWB is a tedious process and in this report readers can understand the various method of generation its advantages and its drawbacks. Modulation and demodulation scheme gives clear idea about how UWB are modulated and demodulated as well as its probability of error and in which situation which modulation is suitable. By using future testbed concept, smaller size UWB chip will be designed and used in various application efficiently. Application gives clear idea about how to take advantage of various properties.

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Elmegri, Fauzi O. M. "Model and design of small compact dielectric resonator and printed antennas for wireless communications applications : model and simulation of dialectric resonator (DR) and printed antennas for wireless applications : investigations of dual band and wideband responses including antenna radiation performance and antenna design optimization using parametric studies". Thesis, University of Bradford, 2015. http://hdl.handle.net/10454/14742.

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Dielectric resonator antenna (DRA) technologies are applicable to a wide variety of mobile wireless communication systems. The principal energy loss mechanism for this type of antenna is the dielectric loss, and then using modern ceramic materials, this may be very low. These antennas are typically of small size, with a high radiation efficiency, often above 95%; they deliver wide bandwidths, and possess a high power handling capability. The principal objectives of this thesis are to investigate and design DRA for low profile personal and nomadic communications applications for a wide variety of spectrum requirements: including DCS, PCS, UMTS, WLAN, UWB applications. X-band and part of Ku band applications are also considered. General and specific techniques for bandwidth expansion, diversity performance and balanced operation have been investigated through detailed simulation models, and physical prototyping. The first major design to be realized is a new broadband DRA operating from 1.15GHz to 6GHz, which has the potential to cover most of the existing mobile service bands. This antenna design employs a printed crescent shaped monopole, and a defected cylindrical DRA. The broad impedance bandwidth of this antenna is achieved by loading the crescent shaped radiator of the monopole with a ceramic material with a permittivity of 81. The antenna volume is 57.0  37.5  5.8 mm3, which in conjunction with the general performance parameters makes this antenna a potential candidate for mobile handset applications. The next class of antenna to be discussed is a novel offset slot-fed broadband DRA assembly. The optimised structure consists of two asymmetrically located cylindrical DRA, with a rectangular slot feed mechanism. Initially, designed for the frequency range from 9GHz to 12GHz, it was found that further spectral improvements were possible, leading to coverage from 8.5GHz to 17GHz. Finally, a new low cost dual-segmented S-slot coupled dielectric resonator antenna design is proposed for wideband applications in the X-band region, covering 7.66GHz to 11.2GHz bandwidth. The effective antenna volume is 30.0 x 25.0 x 0.8 mm3. The DR segments may be located on the same side, or on opposite sides, of the substrate. The end of these configurations results in an improved diversity performance.

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36

Elmegri, Fauzi. "Model and design of small compact dielectric resonator and printed antennas for wireless communications applications. Model and simulation of dialectric resonator (DR) and printed antennas for wireless applications; investigations of dual band and wideband responses including antenna radiation performance and antenna design optimization using parametric studies". Thesis, University of Bradford, 2015. http://hdl.handle.net/10454/14742.

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Dielectric resonator antenna (DRA) technologies are applicable to a wide variety of mobile wireless communication systems. The principal energy loss mechanism for this type of antenna is the dielectric loss, and then using modern ceramic materials, this may be very low. These antennas are typically of small size, with a high radiation efficiency, often above 95%; they deliver wide bandwidths, and possess a high power handling capability. The principal objectives of this thesis are to investigate and design DRA for low profile personal and nomadic communications applications for a wide variety of spectrum requirements: including DCS, PCS, UMTS, WLAN, UWB applications. X-band and part of Ku band applications are also considered. General and specific techniques for bandwidth expansion, diversity performance and balanced operation have been investigated through detailed simulation models, and physical prototyping. The first major design to be realized is a new broadband DRA operating from 1.15GHz to 6GHz, which has the potential to cover most of the existing mobile service bands. This antenna design employs a printed crescent shaped monopole, and a defected cylindrical DRA. The broad impedance bandwidth of this antenna is achieved by loading the crescent shaped radiator of the monopole with a ceramic material with a permittivity of 81. The antenna volume is 57.0  37.5  5.8 mm3, which in conjunction with the general performance parameters makes this antenna a potential candidate for mobile handset applications. The next class of antenna to be discussed is a novel offset slot-fed broadband DRA assembly. The optimised structure consists of two asymmetrically located cylindrical DRA, with a rectangular slot feed mechanism. Initially, designed for the frequency range from 9GHz to 12GHz, it was found that further spectral improvements were possible, leading to coverage from 8.5GHz to 17GHz. Finally, a new low cost dual-segmented S-slot coupled dielectric resonator antenna design is proposed for wideband applications in the X-band region, covering 7.66GHz to 11.2GHz bandwidth. The effective antenna volume is 30.0 x 25.0 x 0.8 mm3. The DR segments may be located on the same side, or on opposite sides, of the substrate. The end of these configurations results in an improved diversity performance.
General Secretariat of Education and Scientific Research Libya

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Tall, Ndiogou. "Etude et réalisation de circuits de récupération d'horloge et de données analogiques et numériques pour des applications bas débit et très faible consommation". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4717.

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Les circuits de récupération d'horloge et de données sont nécessaires au bon fonctionnement de plusieurs systèmes de communication sans fil. Les travaux effectués dans le cadre de cette thèse concernent le développement de ces circuits avec d'une part la réalisation, en technologie HCMOS9 0,13 μm de STMICROELECTRONICS, de circuits CDR analogiques à 1 et 54 Mbit/s, et d'autre part, la mise en œuvre de fonctions CDR numériques programmables à bas débit. Un circuit CDR fonctionnant à plus bas débit (1 Mbit/s) a été conçu dans le cadre de la gestion d'énergie d'un récepteur ULB impulsionnel non cohérent. Ces deux structures ont été réalisées à l'aide de PLL analogiques du 3ème ordre. Un comparateur de phase adapté aux impulsions issues du détecteur d'énergie a été proposé dans cette étude. Les circuits ont ensuite été dimensionnés dans le but d'obtenir de très bonnes performances en termes de jitter et de consommation. En particulier, les performances mesurées (sous pointes) du circuit CDR à 1 Mbit/s permettent d'envisager une gestion d'énergie efficace (réduction de plus de 97% de la consommation du récepteur). Dans le cadre d'une chaîne de télémesure avion vers sol, deux circuits CDR numériques ont également été réalisés durant cette thèse. Une PLL numérique du second degré a été implémentée en vue de fournir des données et une horloge synchrone de celles-ci afin de piloter une chaîne SOQPSK entièrement numérique. Un circuit ELGS a également mis au point pour fonctionner au sein d'un récepteur PCM/FM
Clock and data recovery circuits are required in many wireless communication systems. This thesis is about development of such circuits with: firstly, the realization, in HCMOS9 0.13 μm of STMICROELECTRONICS technology, of 1 and 54 Mb/s analog CDR circuits, and secondly, the implementation of programmable digital circuits at low rates. In the aim of an impulse UWB transceiver dealing with video transmission, a CDR circuit at 54 Mb/s rate has been realized to provide clock signal synchronously with narrow pulses (their duration is about a few nanoseconds) from the energy detector. Another CDR circuit has been built at 1 Mb/s rate in a non-coherent IR- UWB receiver power management context. Both circuits have been implemented as 3rd order analog PLL. In this work, a phase comparator suitable for “RZ low duty cycle” data from the energy detector has been proposed. Circuits have been sized to obtain very good performances in terms of jitter and power consumption. Particularly, measured performances of the 1 Mb/s CDR circuit allow to plan an efficient power management (a decrease of more than 97% of the receiver total power consumption). In the context of a telemetry system from aircraft to ground, two digital CDR circuits have also been implemented. A second order digital PLL has been adopted in order to provide synchronous clock and data to an SOQPSK digital transmitter. Also, a digital ELGS circuit has been proposed to work in a PCM/FM receiver. For both CDR structures, the input signal rate is programmable and varies globally from 1 to 30 Mb/s

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BABIKER, ALADDIN. "DESIGN MIMO ANTENNA FOR UWB APPLICATIONS". Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16817.

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Ultra Wide Band (UWB) technology is rapidly developing area in the field of Wireless Communication. There are many challenges in this field, one of the challenge is to design an antenna which covers the entire UWB frequency range, the another challenge is to design an UWB Multiple input-Multiple output (MIMO) antenna which will increase the channel capacity and will allow several users to access the various services at the same time. The objective of this thesis is to design UWB antenna that operates in the frequency range from 3.1 to 10.6 GHz. Another objective is to design UWB MIMO antenna. The thesis starts with designing and implementing UWB antennas with discussions covering their operation, electrical behavior and performance. UWB antenna was designed and analyzed using microstrip feeding technique to achieve low profile. In Communication systems, Multiple Input–Multiple Output (MIMO) technology, which involves the use of multiple antennas at both the transmitter and receiver, is used to significantly enhance the data transmission performance and channel capacity. Antenna for this system was designed, to ensure that isolation between elements should be less than - 15 dB. The UWB MIMO antenna consists of four elements and designed with substrate FR-4 having the size 43mm x 43mm x 0.8mm. Results the designed antenna has an impedance bandwidth from 2.6GHz to 10.8GHz as well as isolation i.e. S21≤ -18 dB. Radiation efficiency up to 0.95. Envelope correlation coefficient (ECC≤ 0.007 ) , TARC (≤ -34dB) and diversity gain (≥ 9.96 dB).

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WANG, LE-YU, i 王樂彧. "A Study of Antennas for Wireless USB Dongle and UWB Applications". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/up43nq.

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碩士
明志科技大學
電機工程系碩士班
104
In recent years, wireless communication have been a necessary research topic due to get better communication quality, and develop a faster and convenient wireless network.Two antennas have been proposed in the paper, they are triple band suited for USB application and symmetric slot-type UWB antenna. The first one is USB antenna, occupies a area of 10× 10mm2 and its impedance band width covering 2.3-2.69GHz、3.3-3.7GHz and 5.15-5.85GH based on return loss > 10dB. The antenna is designed at a monopole type with branches and etched on a 0.8mm thick FR4 Substrate. By using the monopole design to excite three wide-band, its resonant electrical-lengths are calculated about λ/4 at operating frequencies and to satisfy the working frequency band of our design target. The second antenna, a symmetric slot-type UWB antenna, occupies a area of 28×20mm2 and covers a operating band from 3.1-10.6GHz, To avoiding the interferences resulting existing 3.4-3.7GHz and 5.15-5.85GHz, two notched bands functions are designed. The overall antenna is designed based on a rectangular shape, adopting a back-side substrate to couple each other and reaching our target by using two slots design. The mentioned above two antennas are designed by using a tool of Ansoft HFSS to simulate return loss and impedance characteristics, and then using a precise network analyzer Agilent E8362B and etching machine LPKF E33 to finish two antennas the simulated and tests , and that they are worth of prove commercial values.

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Mandalanka, Anil Kumar. "UWB pulse generation for GPR applications". Thesis, 2013. http://ethesis.nitrkl.ac.in/5020/1/UWB_PULSE_GENERATION_FOR_GPR.pdf.

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In this work, we present a low-complexity, and low cost ultra-wideband (UWB) pulse generators for GPR applications. Here we have implemented two UWB pulse generator circuits. The first pulse generator uses a simple common emitter amplifier followed by RC high-pass filter to generate the Gaussian pulse directly. The circuit provides a Gaussian pulse when activated by a square wave of an external trigger signal and also the pulse width duration tunability by varying the frequency. Using this circuit topology we can achieve 200ns Gaussian pulse. The second UWB pulse generator is based on the avalanche transistor. This pulse generator also provides a Gaussian pulse when activated by a square wave of an external trigger signal. And when activated with 3 kHz square wave, it generates 11ns duration Gaussian pulse.

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41

Elmegri, Fauzi, Chan H. See, Raed A. Abd-Alhameed, Chemseddine Zebiri i Peter S. Excell. "Dielectric resonator antenna design for UWB applications". 2013. http://hdl.handle.net/10454/9648.

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No
A small dielectric resonator antenna has been designed for ultra wideband (UWB) communication system applications. The antenna element is a rectangular low permittivity ceramic block, with a dielectric constant of 9.4, and the modified T-shaped feed network includes a 50 ohm microstrip line to achieve strong coupling, and some bandwidth enhancement. The antenna performance is simulated and measured over a frequency band extending from 3100 MHz to 5500 MHz; the impedance bandwidth over this interval is 55.8% with VSWR <; 2, making the antenna suitable for UWB applications.

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Shah, Akshat, i Kaveesh Sharma. "Design of Rectangular DRA for UWB Applications". Thesis, 2012. http://ethesis.nitrkl.ac.in/3587/1/Final_THESIS.pdf.

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The world has seen difficulty in handling of huge size antennas with high maintenance cost. Dielectric Resonator Antenna (DRA) has some interesting characteristics that provide a solution from its characteristics like small size, high radiation efficiency, low losses, high power handling capacity, increased bandwidth and ease to integrate with existing technologies. Here, a slotted rectangular type of DRA of Ultra-Wide band (UWB) applications is presented. The design combines advantage of small size DRA and thin planar monopole antenna. Antenna size is 15X33 mm2 with 5.08 mm thickness. The Dielectric Resonator is shaped to house excitation feed using microstrip line feed. Air gaps are introduced / enhanced between the line feed and ground to improve the bandwidth. Two slots of (1×1) mm2 dimensions are also introduced in the DR. Proposed antenna results in a better return loss and is below -10 dB within range (3.3296 – 12.536) GHz and resonance frequency 4.811 GHz.The antenna is thin and compact which makes it easily portable. A maximum gain of 3.66 dB achieved at 4.811 GHz frequency. The VSWR parameter was found to be less than 2 within the operating frequency range. It can be used for WLAN, WiMax applications in the frequency range 5.2 to 5.8 GHz.

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Prusty, Abhisek. "GPR applications by using UWB pulse generation". Thesis, 2014. http://ethesis.nitrkl.ac.in/6508/1/E-18.pdf.

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In this work of my last year venture I speak to a low many-sided quality and ease ultra-wideband (UWB) pulse generator for GPR requisitions. Here I have actualized one UWB pulse generator circuit. The UWB pulse generator is based on the avalanche transistor. This pulse generator circuit provides a Gaussian pulse when it is given by a square wave of an external triggered signal. And further more when it is enacted with 3 kHz square wave, it creates 13ns span Gaussian pulse.

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44

連崇哲. "Design and Applications of Band Notched UWB Antenna". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/51688514045360424932.

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碩士
逢甲大學
電機工程學系
101
This paper presents five monopole antennas with three-tier small semicircles for ultra-wideband operation. The main configuration of this Ultra-Wide-Band(UWB) antenna is categorized as a kind of rectangular monopole antenna. Analyzing the current distribution and some parameters such as the size, feeding line width, ground width, radiator, taper and slot of antennas, we experimentally and technically discuss how to adequately affect the antenna’s return loss (S11). Ultra-wideband (UWB) applications a bandwidth of 3.1 GHz ~ 10.6 GHz, the return loss is less than -10 dB in the range of 7.5 GHz bandwidth. The monopole antenna with three-tier small semicircles which can get wider bandwidth is done by etching process on the FR4 substrate with 1.6mm in thickness and 4.4 relative permittivity. For designing process is divided into three parts, the 50-ohm impedance feeding line is connected to the larger semicircle which the fundamental mode is 3GHz, firstly. Secondly, considering four, eight and sixteen semicircles with their radius are 1/4, 1/8, 1/16 times greater than the larger semicircle&;#39;s radius, and then place them above the larger semicircle. Finally, the larger rectangle on opposite sides of the FR4 PCB. The S11 frequency response , radiation patterns, power gain, group delay, received pulse response, and phase change are also investigated. The relevant research reports can prove that a monopole antenna with three-tier small semicircles are very suitable for applications in ultra-wideband short-range wireless devices and apply to medical image.

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45

Lashab, Mohamed, Hmeda I. Hraga, Raed A. Abd-Alhameed, Chemseddine Zebiri, F. Benabdelaziz i Steven M. R. Jones. "Horn Antennas Loaded with Metamaterial for UWB Applications". 2011. http://hdl.handle.net/10454/5466.

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Yes
In this paper, a conical horn antenna has been designed for Ultra-Wideband ap-plications by loading its section with a metamaterial. The work aims first to compare results obtained by the wavelet-moment method to a simulation performed using HFSS. Secondly the conical horn is loaded with a very thin layer of metamaterial to enhance the radiation pattern and the bandwidth performance of the conical horn antenna and reduce the size of the antenna. The operating bandwidth of the proposed antenna is in the range of 10{13 GHz. The results obtained from HFSS and moment method are in good agreement.
Electronics and Telecommunications

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46

Ramesh, Vankudothu. "Design of Dielectric Resonator Antennas for UWB Applications". Thesis, 2016. http://ethesis.nitrkl.ac.in/9155/1/2016_MT_VRamesh.pdf.

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Present consequence of communication, all wired ones become as wireless. So, to get capable and affordable communication in wireless technology, compacted and effective radiators are requisite. One of the effective radiators is dielectric resonator antenna (DRA). So the applied power lost in radiated field, to overcome this problem dielectric resonator antenna (DRA) is considered, with this striking feature dielectric resonator antenna become considerable in wireless communication field at microwave frequencies. This thesis shows the design of dielectric resonator antenna (DRA) which consists of parametric studies of the return loss, gain, radiation patterns and directivity for particular wireless application. Dielectric resonator antennas became a very popular in the core sectors of a nation like defense, military, radar and specifically for millimeter wave applications. Due to this elasticity in dielectric resonator antennas, they can be intended with different shapes, handling requirements depending upon the applications in wireless communications. In this, different shapes of DRA’s are designed and these antennas are well suitable for UWB applications. The operating frequency range is 3.1GHz to 10.6GHz. In the first design H-shape DRA is designed, it operates at resonance frequencies 3.3909GHz, 10.1518GHz and gives high return loss. In the second design E-shape DRA is designed, it operates the frequency range from 6.8353GHz to 10.9892GHz and gives bandwidth 47.9%. So based on operating frequency range these two designs suitable for ultra wide band applications. In this rectangular DRA and A-shape DRA’s are designed and compared, based on physical requirements of DRA and characteristics A-shape DRA gives good E-cut radiation pattern, return loss. In the last design omnidirectional U-shaped DRA is investigated. This design operates the frequency range from 3.0083GHz to 10.0532GHz. Based on characteristics and physical requirements these all designs are suitable for ultra wide band applications.

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47

Tai-Shun, Fu, i 傅泰順. "Design of RF Front-end Circuits for UWB Applications". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/11071089027403745453.

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碩士
長庚大學
電子工程研究所
94
Abstract This thesis presents the development of IEEE 802.15.3a UWB RF front-end circuit with TSMC 0.18µm standard CMOS technology. The study is to integrate the transceiver circuit into a single chip to benefit the integration of the base-band circuit and to realize the manufacture of SoC (System on a Chip). Hence, the manufacturing cost can be reduced considerably. This thesis contains three parts, including power amplifier, low noise amplifier and down conversion mixer. Planning the arrangement of the system, the RF frequency range is 3.1 to 10.6 GHz. The supply voltage is 1.8V. The base-band frequency is 100MHz. In this thesis, power amplifier has a gain of 13.5dB and output power of about 12dBm. Input and output return losses are smaller than those of -10dB and -5.4dB, respectively. P1dB and IIP3 are -7dBm and 7.7dBm, respectively. PAE and power consumption are 28%, 40mW, respectively. Low noise amplifier has a gain of 11dB and noise figure is smaller than 4.5dB. Input and output return losses are smaller than -10dB and -11.5dB, respectively. P1dB and IIP3 are -12dBm and -7.4dBm, respectively. Power consumption is 13mW. Down conversion mixer has a conversion gain of 5dB and single-sideband noise figure is smaller than 13dB. Return loss of RF Port is smaller than -8.3dB. Return loss of IF port is -18.6dB. P1dB and IIP3 are -11dBm and -8dBm, respectively. Power consumption is 29.16mW. The circuits are simulated by Advanced Design System (ADS) and TSMC 0.18µm 1P6M CMOS process.

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48

Kianpour, Iman. "Design of a low power transmitter for UWB applications". Doctoral thesis, 2019. https://hdl.handle.net/10216/123604.

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49

Ku, Kuang Yuan, i 古光原. "Small open slot antenna for WLAN/WiMAX/UWB applications". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/51129656783883170937.

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碩士
南台科技大學
電子工程系
95
In this thesis, we proposed open slot antenna designs, including band-rejected and enhance bandwidth for WLAN, WiMAX and UWB applications. In practical applications, broadband antenna must use filter to suppress dispensable bands lead to increase cost. First, the broadband characteristic (2.3~6.1GHz) of open slot antenna design with small size is proposed. Then, by inserting strip on printed open slot of the broadband antenna to reject dispensable bands, a dual-broadband design of the open slot antenna with small size is obtained for WLAN applications in the 2.4/5GHz bands. Furthermore, inserting two strips of different length on open slot antenna to rejected dual-band, a three-band antenna is achieved. By adjusting the dimension of two strips on open slot antenna, a three operating modes frequencies at 2.5/3.5/5.5 GHz for WiMAX (Worldwide Interoperability for Microwave Access) application has been obtained. Finally, a novel open slot antenna for bandwidth enhancement is presented. The bandwidth enhancement of the proposed antenna is achieved by cutting two notches along the invert-L shape open slot in the ground plane. The frequency range of the proposed antenna is from 2.3 to 10.9 GHz, which can cover UWB frequency range (3.1~10.6 GHz).

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50

Chen, Wei-Chih, i 陳韋志. "The Research of Antenna for WLAN/ WiMax / UWB Applications". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/31273920560392101394.

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碩士
崑山科技大學
電腦與通訊研究所
100
The main proposal for this thesis is three antenna types, one of which is the asymmetric monopole antenna. This antenna structure is to create the broadband impedance match by feeding it through the middle of a two-tier board. In addition to this is the smaller radiator has been fitted with an open slot to expand the bandwidth of the high frequency oscillation. As a result the entire design of this antenna can achieve the dual-band and broadband characteristics, including the frequency range of 2.31-3.83GHz and 4.88-6.0GHz. This antenna can also be applied to the WLAN and WiMAX systems. The second structure is the monopole antenna, which is connected by the gap between the symmetrical bevel ground and the radiator to create an oscillation broadband. Then through the ground ladder grove it will allow the antenna to achieve Ultra-wideband features, including the frequency range of 2.3-15.28GHz and usable in the WLAN, WiMAX and UWB bands. The third structure is the patch antenna. It is constructed by using the square radiator and a U slot type of the ground. This is due to the box design which allows the antenna field type radiation pattern to go up and high-gain characteristics. It has the frequency range of 2.34-2.52GHZ and it can be used in the WLAN band. In this thesis, these three antenna structures, bandwidth, gain value and the radiation patterns provide comparing results such as simulation and implementation upon discussion.

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