1,133 research outputs found

    UWB implementation and utilization in mPOS device

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    Abstract. This thesis investigates the possible implementation and utilization of ultra-wideband (UWB) technology in a handheld device that serves as a sales system. The basic information of UWB technology based on theory is introduced, such as history, benefits and challenges, current standards, and the most common use cases. The general requirements and the planned use cases for UWB technology are presented to narrow the scope of the thesis. The thesis covers status of the current suppliers of UWB components and reasonings of the selection of a UWB chip and antennas for this thesis. Measurements are performed with the UWB chip, the UWB antennas and the entire UWB system implementation to verify that the requirements are met, and the technology works as designed. Based on theory and measurement results, it is demonstrated that both the implementation and utilization of UWB in the handheld device with the desired characteristics can be done

    An Analysis of Electromagnetic Interference (EMI) of Ultra Wideband(UWB) and IEEE 802.11A Wireless Local Area Network (WLAN) Employing Orthogonal Frequency Division Multiplexing (OFDM)

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    Military communications require the rapid deployment of mobile, high-bandwidth systems. These systems must provide anytime, anywhere capabilities with minimal interference to existing military, private, and commercial communications. Ultra Wideband (UWB) technology is being advanced as the next generation radio technology and has the potential to revolutionize indoor wireless communications. The ability of UWB to mitigate multipath fading, provide high-throughput data rates (e.g., greater than 100 Mbps), provide excellent signal penetration (e.g., through walls), and low implementation costs makes it an ideal technology for a wide range of private and public sector applications. Preliminary UWB studies conducted by The Institute for Telecommunications Science (ITS) and the Defense Advanced Research Projects Agency (DARPA) have discovered that potential exists for harmful interference to occur. While these studies have provided initial performance estimates, the interference effects of UWB transmissions on coexisting spectral users are largely unknown. This research characterizes the electromagnetic interference (EMI) effects of UWB on the throughput performance of an IEEE 802.11a ad-hoc network. Radiated measurements in an anechoic chamber investigate interference performance using three modulation schemes (BPSK, BPPM, and OOK) and four pulse repetition frequencies over two Unlicensed National Information Infrastructure (U-NII) channels. Results indicate that OOK and BPPM can degrade throughput performance by up to 20% at lower pulse repetition frequencies (PRFs) in lower U-NII channels. Minimal performance degradation (less than one percent) due to interference was observed for BPSK at the lower PRFs and higher U-NII channels

    Is re-farming the answer to the spectrum shortage conundrum?

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    Radio spectrum has become one of the engines of economic growth. However, rapid technological change, ever increasing demands for new wireless services and the nature of spectrum as a scarce resource necessitate an urgent re-examination of issues such as congestion and interference. This paper argues that the traditional administrative spectrum management approach is unlikely to overcome these issues, thereby resulting in growing technical and economic inefficiencies. As countries review their spectrum policies - a process that is generically referred to as radio spectrum policy reform - to counter these inefficiencies, modifications to the radio frequency allocations and assignments are beginning to be implemented by way of radio spectrum re-farming? This phenomenon forms the subject matter of this paper

    Ultra Wideband

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    Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

    Design and Implementation of a UWB Radar Sensor for Non-Destructive Application

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    [ES] Debido a la importancia de los campos de aplicación del sensor de radar de banda ultraancha, y también a los requisitos de cada aplicación específica, existe una demanda creciente de diseño compacto, de bajo coste y alta precisión del sensor de radar de banda ultraancha. Para responder a estas exigencias, esta tesis pretende proponer un sensor de radar UWB avanzado. Este trabajo de investigación se centra en el diseño del sensor de radar de banda ultraancha (UWB) para aplicaciones no destructivas (END). Los detalles de diseño incluyen el diseño de un generador de pulsos ultracorto, de alta potencia con un timbre mínimo. El radar desarrollado fue construido con una configuración biestática. El objetivo de este trabajo es medir el rango de distancia y las propiedades eléctricas de un objetivo, por ejemplo, metales y materiales dieléctricos, como el cloruro de polivinilo (PV C). Para lograr este objetivo, se ha desarrollado un novedoso generador de pulsos de alta potencia ultra-corto (pulsador de radar). El nuevo generador de pulsos consiste en un transistor que funciona en modo de avalancha y un circuito de afilado de pulsos que utiliza un nuevo modelo de diodo de recuperación de paso (SRD). Para convertir el pulso gaussiano en un monociclo, se ha añadido una red de formación de monociclo (MFN). El generador de impulsos desarrollado produce un impulso eléctrico con una amplitud de 12 V, un tiempo de subida de 112 ps y un ancho de impulso (FWHM) de 155 ps. Con el fin de aumentar la amplitud de los pulsos, se han propuesto dos técnicas útiles en este trabajo. El primero consiste en agregar dos generadores en paralelo, en este diseño propuesto se tuvo en cuenta alguna especificación para hacer que este circuito funcione. Sin embargo, la segunda técnica adoptada en este trabajo consiste en dos etapas de generadores, ambas técnicas dan lugar a un buen rendimiento; en lugar de un solo módulo de un generador de impulsos, las técnicas propuestas en este trabajo aumentan la amplitud en torno al doble. Ambas técnicas han sido investigadas en detalle. Para transmitir y recibir los impulsos ultracortos generados, se utilizaron dos tipos diferentes de antenas UWB. En primer lugar, una antena Vivaldi con un ancho de banda de unos 5,5 GHz de 600 MHz a 6 GHz. La segunda es una antena Vivaldi con un ancho de banda de 6 GHz de 400 Mhz a 6,2 GHz. Utilizando el sensor de radar de banda ultraancha desarrollado, se realizaron mediciones de prueba. Esto incluye las propiedades eléctricas, así como la medición de la distancia a las placas de metal, madera y PVC. La incertidumbre del sensor de radar es de 14 mm (datos medidos asustados a + 14 mm para un blanco fijo). El diseño y la implementación real que conduce a lograr un excelente prototipo de rendimiento para una aplicación no destructiva.[CA] A causa de la rellevància dels camps d'aplicació del sensor de radar d'ultra banda ampla, i també l'exigència de cada aplicació específica, hi ha una demanda creixent de disseny compacte, de baix cost i alta precisió del sensor de radar d'ultra banda ampla. Amb la intenció d'atendre aquestes demandes, aquesta tesi pretén proposar un sensor avançat de radar UWB. Aquest treball de recerca tracta del disseny del sensor de radar d'ultra-banda ampla (UWB) per a aplicacions no destructives (NDT). Els detalls del disseny inclouen el disseny d'un pols de monocicle amb pols de potència d'alta potència i amb un mínim de timbre. El radar desenvolupat va ser construït en configuració bi-estàtica. L'objectiu d'aquest treball és mesurar el rang de distància i les propietats elèctriques d'un objectiu, per exemple, materials metàl·lics i dielèctrics, com el clorur de polivinil (PV C). Per assolir aquest objectiu, s'ha desenvolupat un nou ultrasò, generador de pols d'alta potència (polsador de radar). El nou generador de pols està format per un transistor que funciona en mode d'allaus i un circuit d'afilat de pols mitjançant un nou model de díode de recuperació de pas (SRD). Per a convertir el pols gaussiano en un monocicle, s'ha afegit una xarxa de formació de monocicles (MFN). El generador de polsos desenvolupat produeix un pols elèctric amb una amplitud de 12 V, un temps d'augment de 112 ps i un ample de pols (FWHM) de 155 ps. Amb l'objectiu d'augmentar l'amplitud dels polsos, s'han proposat dues tècniques útils en aquest treball. El primer consisteix a afegir dos generadors de forma paral·lela, en aquest disseny proposat, cal tenir en compte algunes especificacions per a fer la viabilitat d'aquest circuit. No obstant això, la segona tècnica adoptada en aquest treball consisteix en una doble etapa de generadors, ambdues tècniques donen lloc a una bona actuació; en lloc d'un únic mòdul d'un generador de pols, les tècniques proposades en aquest treball augmenten l'amplitud al voltant del doble. Per transmetre i rebre polsos ultra-curts generats, s'han utilitzat dos tipus diferents d'antenes UWB. En primer lloc, una antena de Vivaldi amb un ample de banda d'uns 5,5 GHz de 600 MHz a 6 GHz. Mentre que la segona és una antena Vivaldi amb un ample de banda de 6 GHz de 400 MHz a 6.2 GHz. Mitjançant el sensor de radar ultra-ampla desenvolupat, es va realitzar la mesura de la prova. Incloïen propietats elèctriques i mesures de distància a les plaques metàl·liques, fusta i PVC. S'ha trobat que la incertesa del sensor de radar és de 14 mm (dades mesurades espantades entre + 14 mm per a un objectiu fix). El disseny i la implementació real condueixen a aconseguir un excel·lent prototip de rendiment per a una aplicació no destructiva.[EN] Due to the relevance of application fields of ultra-wideband radar sensor, and also the requirement of each specific application, there is an increasing demand of compact, low cost and high accuracy design of ultra-wideband radar sensor. With a view to addressing these demands, this thesis aims to propose an advanced UWB radar sensor. This research work deals with the design of the ultra-wideband (UWB) radar sensor for non-destructive (NDT) application. The design details include the design of ultra-short, high power pulse generator monocycle pulse with a minimum of ringing. The developed radar was build in bi-static configuration. The goal of this work is to measure the distance range and electrical properties of a target e.g, metal and dielectric materials, such as Polyvinyl chloride (PV C). To achieve this goal, a novel ultrashort, high power pulse generator (radar pulser) has been developed. The new pulse generator consists of a transistor operating in avalanche mode and a pulse sharpening circuit using a new model of step recovery diode (SRD). In order to converts the Gaussian pulse to a monocycle, a monocycle forming network (MFN) has been added. The developed pulse generator produces an electrical pulse with an amplitude of 12 V, a rise-time of 112 ps and pulse width (FWHM) of 155 ps. For the purpose to increase the amplitude of the pulses, two useful techniques have been proposed in this work. The first one consist of adding two generators in parallel, in this proposed design some specification was be taking into account to making the workability of this circuit. However, the second technic adopted in this work consists of a two-stage of generators, both technics give rise to a good performance; instead of a single module of a pulse generator, the techniques proposed in this work increase the amplitude around the double. In order to transmit and receive the generated ultra-short pulses, two different types of UWB antennas have been used. First, a Vivaldi antenna with a bandwidth of about 5.5 GHz from 600 MHz to 6 GHz. While the second is a Vivaldi antenna with a bandwidth of 6 GHz from 400 Mhz to 6,2 GHz. Using the developed ultra-wideband radar sensor, test measurement was performed. These included electrical properties as well as distance measurement towards metal plates, wood, and PVC. The uncertainty of the radar sensor has been found to be 14 mm (measured data scared within + 14 mm for a fixed target). The design and real implementation leading to achieve excellent performance prototype for a non-destructive application.Ahajjam, Y. (2019). Design and Implementation of a UWB Radar Sensor for Non-Destructive Application [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124057TESI

    Technology Implications of UWB on Wireless Sensor Network-A detailed Survey

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    In today’s high tech “SMART” world sensor based networks are widely used. The main challenge with wireless-based sensor networks is the underneath physical layer. In this survey, we have identified core obstacles of wireless sensor network when UWB is used at PHY layer. This research was done using a systematic approach to assess UWB’s effectiveness (for WSN) based on information taken from various research papers, books, technical surveys and articles. Our aim is to measure the UWB’s effectiveness for WSN and analyze the different obstacles allied with its implementation. Starting from existing solutions to proposed theories. Here we have focused only on the core concerns, e.g. spectrum, interference, synchronization etc.Our research concludes that despite all the bottlenecks and challenges, UWB’s efficient capabilities makes it an attractive PHY layer scheme for the WSN, provided we can control interference and energy problems. This survey gives a fresh start to the researchers and prototype designers to understand the technological concerns associated with UWB’s implementatio

    Wave tomography

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    A Self-organizing Hybrid Sensor System With Distributed Data Fusion For Intruder Tracking And Surveillance

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    A wireless sensor network is a network of distributed nodes each equipped with its own sensors, computational resources and transceivers. These sensors are designed to be able to sense specific phenomenon over a large geographic area and communicate this information to the user. Most sensor networks are designed to be stand-alone systems that can operate without user intervention for long periods of time. While the use of wireless sensor networks have been demonstrated in various military and commercial applications, their full potential has not been realized primarily due to the lack of efficient methods to self organize and cover the entire area of interest. Techniques currently available focus solely on homogeneous wireless sensor networks either in terms of static networks or mobile networks and suffers from device specific inadequacies such as lack of coverage, power and fault tolerance. Failing nodes result in coverage loss and breakage in communication connectivity and hence there is a pressing need for a fault tolerant system to allow replacing of the failed nodes. In this dissertation, a unique hybrid sensor network is demonstrated that includes a host of mobile sensor platforms. It is shown that the coverage area of the static sensor network can be improved by self-organizing the mobile sensor platforms to allow interaction with the static sensor nodes and thereby increase the coverage area. The performance of the hybrid sensor network is analyzed for a set of N mobile sensors to determine and optimize parameters such as the position of the mobile nodes for maximum coverage of the sensing area without loss of signal between the mobile sensors, static nodes and the central control station. A novel approach to tracking dynamic targets is also presented. Unlike other tracking methods that are based on computationally complex methods, the strategy adopted in this work is based on a computationally simple but effective technique of received signal strength indicator measurements. The algorithms developed in this dissertation are based on a number of reasonable assumptions that are easily verified in a densely distributed sensor network and require simple computations that efficiently tracks the target in the sensor field. False alarm rate, probability of detection and latency are computed and compared with other published techniques. The performance analysis of the tracking system is done on an experimental testbed and also through simulation and the improvement in accuracy over other methods is demonstrated

    Radar Technology

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    In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design
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