210 research outputs found

    Wideband and UWB antennas for wireless applications. A comprehensive review

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    A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

    2008 Index IEEE Transactions on Control Systems Technology Vol. 16

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    This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

    2009 Index IEEE Antennas and Wireless Propagation Letters Vol. 8

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    This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

    Novel miniaturized antennas and arrays for implantable, ingestible and body-worn applications

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    University of Technology Sydney. Faculty of Engineering and Information Technology.Implantable medical devices (IMDs) introduced to monitor and transfer physiological information from inside the human body have superb potentials to provide major contributions to disease diagnosis, prevention and therapy. Moreover, minimally invasive biomedical devices helps to reduce the period of long-term hospitalization, so that enhancing the patients’ quality of life. Understanding and developing biotelemetry devices, recording/transmitting data from inside the body to the external base station, requires a multi-disciplinary approach. Such a challenging task merges applied solutions, concepts and models from various fields, including biology, electronics, electromagnetism and package/system engineering. Among the device components, the transmitter antenna plays a key role. Antenna design for biotelemetry applications is extremely challenging due to the effect of the surroundings on the radiator, the essential requirement to miniaturize the antenna structure size, reduced antenna efficiency and the robust effect of multipath losses. More specifically, in this thesis, I design and fabricate several antennas to be integrated in ingestible and implantable devices useful for remote monitoring as well as data biotelemetry. This work also focuses on arrays of body-worn antennas for both wireless endoscope base stations and cancer treatment nearfield microwave systems. Here, my aim is to reduce the physical size of the implantable antennas at specified operating standards frequency bands, while maintaining the antenna electromagnetic performance satisfactory. To achieve this, I introduce and use valuable miniaturization techniques for implantable patch antennas for biotelemetry applications. Additionally, I design and fabricate compact microwave systems for cancer treatment using electromagnetic (EM) energy. Non-Invasive Local Microwave Hyperthermia (NI-LMH), which is my interest in this thesis, is a heat treatment serves to enhance the effectiveness of chemotherapy or radiation therapy and leads to gain remarkable results. The system may directly apply heat to a fairly small specific area such as tumors to destroy the local cancer cells. To achieve this, the heat effect is developed in the target by the transmission of EM energy, using array of antennas, which is adjusted in frequency, time and strength in order to work together to form a focus in the target. This places high demands on the precision of the system. In this thesis, I present different planar antenna array for non-invasive microwave hyperthermia applications. The new Near Field Focused (NFF) arrays operates at ISM 2.45 GHz band and consists of 5 to 25 miniaturized dual slot PIFAs, depends on the array geometry arrangement. The arrays immersed inside a coupling bolus occupies a very small volume of space results in an easy fitting to contoured patient anatomy. These arrays, which are low profile and lightweight, have both superficial and deep focusing properties. The novel NFF body worn arrays are capable to focus on a single target with a high level of accuracy to concentrate the EM energy only on the target. I employ optimized dual slot PIFAs as array elements to reduce the size of the focusing area so that destroying very small tumors and avoid heating up the surrounding healthy cells. I have also introduced size reduced NFF array to simplify the feeding network of the applicator and reduce the system cost, this array configuration satisfies system requirements and can focus on small targets precisely while keep the penetration depth high enough to heat up the deep seated targets. In addition, the performance of both fabricated narrowband and wideband single antennas and array of antennas verified using experimental tissue mimicking phantoms. To validate the dielectric properties of experimental phantoms, over different frequency bands, dielectric probe kit employed, furthermore, optical fibre thermometers employed to confirm specific absorption rate (SAR) values for implanted radiators

    Additive Manufacturing for Antenna Applications

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    This thesis presents methods to make use of additive manufacturing (AM) or 3D printing (3DP) technology for the fabrication of antenna and electromagnetic (EM) structures. A variety of 3DP techniques based on filament, resin, powder and nano-particle inks are applied for the development and fabrication of antennas. Fully and partially metallised 3D printed EM structures are investigated for operation at mainly microwave frequency bands. First, 3D Sierpinski fractal antennas are fabricated using binder jetting printing technique, which is an AM metal powder bed process. It follows with the introduction of a new concept of sensing liquids using and non-planer electromagnetic band gap (EBG) structure is investigated. Such structure can be fabricated with inexpensive fuse filament fabrication (FFF) in combination with conductive paint. As a third method, inkjet printing technology is used for the fabrication of antennas for origami paper applications. The work investigates the feasibility of fabricating foldable antennas for disposable paper drones using low-cost inkjet printing equipment. It then explores the applicability of inkjet printing on a 3D printing substrate through the fabrication of a circularly polarised patch antenna which combines stereolithography (SLA) and inkjet printing technology, both of which use inexpensive machines. Finally, a variety of AM techniques are applied and compared for the production of a diversity WLAN antenna system for customized wrist-worn application

    Design of textile antennas and flexible WBAN sensor systems for body-worn localization using impulse radio ultra-wideband

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    Microwave Devices for Wearable Sensors and IoT

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    The Internet of Things (IoT) paradigm is currently highly demanded in multiple scenarios and in particular plays an important role in solving medical-related challenges. RF and microwave technologies, coupled with wireless energy transfer, are interesting candidates because of their inherent contactless spectrometric capabilities and for the wireless transmission of sensing data. This article reviews some recent achievements in the field of wearable sensors, highlighting the benefits that these solutions introduce in operative contexts, such as indoor localization and microwave sensing. Wireless power transfer is an essential requirement to be fulfilled to allow these sensors to be not only wearable but also compact and lightweight while avoiding bulky batteries. Flexible materials and 3D printing polymers, as well as daily garments, are widely exploited within the presented solutions, allowing comfort and wearability without renouncing the robustness and reliability of the built-in wearable sensor

    Design and development of novel radio frequency identification (RFID) tag structures

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    The objective of the proposed research is to design and develop a series of radio frequency identification (RFID) tag structures that exhibit good performance characteristics with cost optimization and can be realized on flexible substrates such as liquid crystal polymer (LCP), paper-based substrate and magnetic composite material for conformal applications. The demand for flexible RFID tags has recently increased tremendously due to the requirements of automatic identification in various areas. Several major challenges existing in today's RFID technologies need to be addressed before RFID can eventually march into everyone's daily life, such as how to design high performance tag antennas with effective impedance matching for passive RFID IC chips to optimize the power performance, how to fabricate ultra-low-cost RFID tags in order to facilitate mass production, how to integrate sensors with passive RFID tags for pervasive sensing applications, and how to realize battery-free active RFID tags in which changing battery is not longer needed. In this research, different RFID tag designs are realized on flexible substrates. The design techniques presented set the framework for answering these technical challenges for which, the focus will be on RFID tag structure design, characterization and optimization from the perspectives of both costs involved and technical constraints.Ph.D.Committee Chair: Tentzeris, Manos; Committee Member: DeJean, Gerald; Committee Member: Ingram, Mary; Committee Member: Kavadias, Stylianos; Committee Member: Laskar, Jo

    Modelling and characterisation of antennas and propagation for body-centric wireless communication

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    PhDBody-Centric Wireless Communication (BCWC) is a central point in the development of fourth generation mobile communications. The continuous miniaturisation of sensors, in addition to the advancement in wearable electronics, embedded software, digital signal processing and biomedical technologies, have led to a new concept of usercentric networks, where devices can be carried in the user’s pockets, attached to the user’s body or even implanted. Body-centric wireless networks take their place within the personal area networks, body area networks and body sensor networks which are all emerging technologies that have a broad range of applications such as healthcare and personal entertainment. The major difference between BCWC and conventional wireless systems is the radio channel over which the communication takes place. The human body is a hostile environment from radio propagation perspective and it is therefore important to understand and characterise the effect of the human body on the antenna elements, the radio channel parameters and hence the system performance. This is presented and highlighted in the thesis through a combination of experimental and electromagnetic numerical investigations, with a particular emphasis to the numerical analysis based on the finite-difference time-domain technique. The presented research work encapsulates the characteristics of the narrowband (2.4 GHz) and ultra wide-band (3-10 GHz) on-body radio channels with respect to different digital phantoms, body postures, and antenna types hence highlighting the effect of subject-specific modelling, static and dynamic environments and antenna performance on the overall body-centric network. The investigations covered extend further to include in-body communications where the radio channel for telemetry with medical implants is also analysed by considering the effect of different digital phantoms on the radio channel characteristics. The study supports the significance of developing powerful and reliable numerical modelling to be used in conjunction with measurement campaigns for a comprehensive understanding of the radio channel in body-centric wireless communication. It also emphasises the importance of considering subject-specific electromagnetic modelling to provide a reliable prediction of the network performance

    The Design, Fabrication and Practical Evaluation of Body-centric Passive RFID Platforms

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    Passive ultra-high-frequency (UHF) radio-frequency identification (RFID) technology is increasingly being recognized as a compelling approach to utilizing energy- and costefficient wireless platforms for a wireless body area network (WBAN). The development of WBANs has stimulated a lot of research over recent years, as they can offer remarkable benefits for the healthcare and welfare sectors, as well as having innovative sportsrelated applications.This thesis is to evaluate and develop the RFID tags used in an integrated wearable RFID platform working in a realistic environment. Each of the wearable antennas were specifically designed for a target part of the body, such as the back or the hand. The antennas were manufactured in different ways, using copper tape, electro-textiles (Etextile) and embroidered conductive threads. After they had been produced, the tags were subjected to on-body measurement and reliability tests. The reliability tests were performed under tough conditions in which the tags were stretched, for instance, or exposed to high humidity and washing. Our results show that the tags can perform well when worn on-body in a harsh environment.This thesis provides several integrated solutions for wireless wearable devices. By different RFID antenna design and fabrication methods, the RFID tag can be used as the moisture and strain sensor with lightweight, small size, flexible pattern and great dailyuse reliability
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