Download or read book Design of Uwb and Multiple Band Monopole Antennas for Body Centric Wireless Communications written by Yiye Sun and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Design of UWB and Multiple-band Monopole Antennas for Body-centric Wireless Communications" by Yiye, Sun, 孫憶業, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: This thesis presents the designs of Ultra-wideband (UWB) monopole antennas, textile monopole antennas and transparent UWB textile antennas using planar technology for body-centric wireless communications (BCWC). A planar antenna designed using offset-fed and slotted ground plane to extend the operating bandwidth for the industrial, scientific and medical (ISM)band and UWB is proposed. Results show that the antenna can achieve a bandwidth from 2.38 to 14.5 GHz with omni-directional radiation patterns in the E-plane. Agroup of nine planar UWB monopole antennas using different radiator shapes such as triangle, rectangle, square, annual ring, circle, horizontal ellipse, vertical ellipse, pentagon and hexagon for BCWC is studied using computer simulation and measurement. Results show that the monopole antenna having a vertical-elliptical-shape radiator has a relatively better performance than other monopole antennas. Three textile antennas fabricated on fabric materials are studied. The first design is a triple-band textile antenna for wireless-local-area network (WLAN) and worldwide interoperability for microwave access (WiMAX) wireless communication applications. The radiator is composed of two branches and a short stub to generate the resonances at about 2.45, 3.5 and 5.5 GHz, respectively. Simulated and measured results show that the three frequency bands can be set independently. The second design is an UWB antenna consisting of a circular radiator, a tapered feed line and a slotted ground plane. Results show that the antenna can achieve a bandwidth of 3 to 12 GHz. The third design is a compact belt-loop UWB antenna with microstrip-fed. The antenna has a simple elliptical-shaped radiator, a three-step staircase on both sides of the feed line and a slot on the ground plane. It has a very compactsize of 1140=440 mm2and can still achieve a bandwidth of 3.1 to 12.8 GHz. To emulate the on-body conditions, the two UWB antennas are studied in the bending and crumpling conditions due to the curvature of human body. Results show that both UWB textile antennas have quite stable performances throughout the UWB band. The two UWB textile antennas are re-designed using a transparent conductive film (TCF)as the radiator and ground plane on fabric substrate. Results show that the measured reflection coefficients of transparent antennas agree well with the simulated results. However, the measured radiation patterns have large discrepancies with the simulated results, which are mainly due to the uncertain electric properties of TCF in radio frequency. Results show that the antennas have a better performance, in terms ofbandwidth, peak gain and radiation efficiency, than those of other transparent antennas studied before, making our proposed antennas suitable for body-centric wireless communications. DOI: 10.5353/th_b5334879 Subjects: Ultra-wideband antennas Human-computer interaction Wireless communication systems - Equipment and supplies - Design and construction

Download or read book Design of UWB and Multiple band Monopole Antennas for Body centric Wireless Communications written by 孫憶業 and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Antennas and Propagation for Body Centric Wireless Communications Second Edition written by Peter S. Hall and published by Artech House. This book was released on 2012 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Now in a newly updated and revised edition, this timely resource provides you with complete and current details on the theory, design, and applications of wireless antennas for on-body electronic systems. The Second Edition offers readers brand new material on advances in physical phantom design and production, recent developments in simulation methods and numerical phantoms, descriptions of methods for simulation of moving bodies, and the use of the body as a transmission channel. You also find a completely revised chapter on channel characterization and antenna design at microwave frequencies. This cutting-edge volume brings you the state-of-the-art in existing applications like Bluetooth headsets together with detailed treatment of techniques, tools, and challenges in developing on-body antennas for an array of medical, emergency response, law enforcement, personal entertainment, and military applications on the horizon. The book briefs you on energy propagation around and into the body and how to estimate performance of on-body wireless links, and then dives into the nuts-and-bolts of designing antenna systems that deliver the goods. It covers on-body communication channels at microwave frequency bands and at low frequency bands, as well as ultra wideband systems for WPANs and WBANs. You get details on body-centric UWB antennas and channels, as well as advances in wearable mobile, EBG, and smart fabricù antennas for cellular and WLAN communications. Chapters on telemedicine applications, such as remote diagnoses, and implantable medical devices cover crucial propagation issues and other obstacles that need to be addressed. Rounding out the coverage is a section on antenna design for body-sensor networks and their emerging military and space applications. Packed with hands-on guidance from noted experts, this volume will be indispensable for your efforts in designing and improving body-centric communication systems.

Download or read book Ultra Wideband Antennas and Propagation written by Ben Allen and published by John Wiley & Sons. This book was released on 2006-11-02 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing up-to-date material for UWB antennas and propagation as used in a wide variety of applications, "Ultra-wideband Antennas and Propagation for Communications, Radar and Imaging" includes fundamental theory, practical design information and extensive discussion of UWB applications from biomedical imaging, through to radar and wireless communications. An in-depth treatment of ultra-wideband signals in practical environments is given, including interference, coexistence and diversity considerations. The text includes antennas and propagation in biological media in addition to more conventional environments. The topics covered are approached with the aim of helping practising engineers to view the subject from a different angle, and to consider items as variables that were treated as constants in narrowband and wideband systems. Features tables of propagation data, photographs of antenna systems and graphs of results (e.g. radiation patterns, propagation characteristics) Covers the fundamentals of antennas and propagation, as well as offering an in-depth treatment of antenna elements and arrays for UWB systems, and UWB propagation models Provides a description of the underlying concepts for the design of antennas and arrays for conventional as well as ultra-wideband systems Draws together UWB theory by using case-studies to show applications of antennas and propagation in communication, radar and imaging systems The book highlights the unique design issues of using ultra-wideband and will serve both as an introductory text and a reference guide for designers and students alike.

Download or read book Wideband Multiband and Smart Reconfigurable Antennas for Modern Wireless Communications written by Matin, Mohammad A. and published by IGI Global. This book was released on 2015-08-26 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern society thrives on communication that is instant and available at all times, a constant exchange of information that encompasses everything from video streaming to GPS navigation. Experts even suggest that in the near future everything from our cars to our kitchen appliances will be connected to the internet, a feat that would not be possible without advanced wireless technology. Wideband, Multiband, and Smart Reconfigurable Antennas for Modern Wireless Communications showcases current trends and novel approaches in the design and analysis of the antennas that make wireless applications possible, while also identifying unique integration opportunities for antennas and wireless applications to work together. By featuring both theoretical and experimental approaches to integration, this book highlights specific design issues to assist a wide-range of readers including students, researchers, academics, and industry practitioners. This publication features chapters on a broad scope of topics including algorithms and antenna optimization, wireless infrastructure development, wireless applications of intelligent algorithms, antenna architecture, and antenna reconfiguration techniques.

Download or read book Ultrawideband Antennas written by Daniel Valderas and published by World Scientific. This book was released on 2011 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrawideband (UWB) technology, positioned as the cutting edge of research and development, paves the way to meet the emerging demands set by broadband wireless applications, such as high-speed data transmission, medical imaging, short-range radars, electromagnetic testing, etc. This breathtaking resource builds upon the basics of UWB technology to provide a complete compilation of figures of merit along with a vital state-of-the-art of the different antenna alternatives that are to be employed according to the specific application. Without excessive recourse to mathematics, this volume emphasizes on the UWB antenna design and equips readers with practical prediction techniques based on simple formulas and models. The big picture of UWB antenna technology would not be complete without addressing its applications, and this will serve to provide consultants with key clues for slot market searching. Containing over 150 supporting illustrations and figures, this comprehensive overview of UWB technology, antenna design and applications is a vital source of information and reference for R&D organizations, researchers, practitioners, consultants, RF professionals and communication engineers.

Download or read book Ultra Wideband Communications written by Mohammad Abdul Matin and published by BoD – Books on Demand. This book was released on 2011-08-09 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores both the state-of-the-art and the latest achievements in UWB antennas and propagation. It has taken a theoretical and experimental approach to some extent, which is more useful to the reader. The book highlights the unique design issues which put the reader in good pace to be able to understand more advanced research.

Download or read book Multifunctional Ultrawideband Antennas written by Chinmoy Saha and published by CRC Press. This book was released on 2019-03-19 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multifunctional Antennas (MFA) are comparatively a new area for antenna research and finds applications in various modern wireless radios, like Cognitive Radio (CR) in Software Defined Radio (SDR) technology and MIMO technology. This book is first attempt and an invaluable resource which deals with the design and realization of various kinds of multifunctional antennas. After clearly explaining the exclusive features of MFAs, the book presents various designs of such antennas considering versatile modern and upcoming applications. Written by three internationally known researchers, Multi-Functional Ultra Wideband Antennas: Trends, Techniques and Applications: Provides a lucid introduction on UWB systems, historical perspective and discusses various applications of such systems Discusses fundamentals of antennas and its characterization in time and frequency domains, primarily aimed for the beginners in the area Revisits the design and realization of various classical UWB antennas Discusses various techniques of designing frequency-notched UWB antennas and provide detailed comparison of the techniques Deals with the techniques of deriving multiple antenna functionalities from a single antenna Incorporates exclusive discussions on modern reconfigurable antennas and printed and dielectric resonator based MIMO antennas with clear focus on recent and upcoming technological requirements With Multi-Functional Ultra Wideband Antennas: Trends, Techniques and Applications, antenna engineers, communication system engineers, graduate students, academic/industry researchers will gain a thorough knowledge on design of such antennas with clear physical insight and understanding. Chinmoy Saha, PHD, is an associate Professor in the Department of Avionics at Indian Institute of Space Science and Technology, Thiruvananthapuram, Kerala, India. His current research interest includes Microwave Circuits, Engineered Materials, Metamaterial Inspired Antennas and Circuits, reconfigurable and multi-functional antennas for modern wireless applications, Dielectric Resonator antennas, THz antennas and wireless power transfer. He is the author or coauthor of several books, scientific journals and recipient of several prestigious awards. Jawad Yaseen Siddiqui, PHD, is an associate Professor in the Department of Radio Physics and Electronics at University of Calcutta, Kolkata, India. His current research interest includes ultra-wideband antennas, frequency reconfigurable antennas, tapered slot antennas and multi-functional antennas for cognitive radio application. He is the author or coauthor of several books, scientific journals and recipient of prestigious awards. He is a Co-Principal Investigator on Stratosphere Troposphere (ST) Radar Project at the University of Calcutta, Kolkata, India. Yahia M.M. Antar, PHD, is a Professor in the Department of Department of Electrical and Computer Engineering at the Royal Military College of Canada, Kingston, ON, Canada. He is the author or coauthor of several books, scientific journals and recipient of prestigious awards which includes IEEE-Antennas and Propagation Society prestigious Chen-To-Tai Distinguished Educator Award for 2017, 2015 IEEE Canada J. M. Ham outstanding Engineering Education Award, 2014 IEEE Canada RA Fessenden Silver Medal, 2012 Queen’s Diamond Jubilee Medal from the Governor General of Canada and many more.

Download or read book Ultra Wideband Antennas written by Giselle M. Galvan-Tejada and published by CRC Press. This book was released on 2017-12-19 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book: Discusses the developed theory for UWB antennas in frequency and time domains Delivers a brief exposition of numerical methods for electromagnetics oriented to antennas Describes solid-planar equivalence, which allows flat structures to be implemented instead of volumetric antennas Examines the impedance matching, phase linearity, and radiation patterns as design objectives for omnidirectional and directional antennas Addresses the time domain signal analysis for UWB antennas, from which the distortion phenomenon can be modeled Includes illustrative examples, design equations, CST MICROWAVE STUDIO® simulations, and MATLAB® plot generations Compares the performance of different UWB antennas, supplying useful insight into particular tendencies and unresolved problems Ultra Wideband Antennas: Design, Methodologies, and Performance provides a valuable reference for the scientific community, as UWB antennas have a variety of applications in body area networks, radar, imaging, spectrum monitoring, electronic warfare, wireless sensor networks, and more.

Download or read book Ultra wideband Antennas and Components for Wireless Communication Systems written by Osama Mohamed Haraz Ahmed and published by . This book was released on 2011 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-wideband (UWB) technology is rapidly developing as a high speed, and high data rate wireless communication mode. There are many challenges in dealing with this new emerging technology. One of these challenges is how to design an antenna ele-ment that can operate effectively in the entire UWB frequency range. Another big chal-lenge is to design UWB antenna beamforming systems including suitable UWB compo-nents such as feed networks, transitions, crossovers, hybrid couplers and phase shifters to meet the UWB requirements. This thesis is primarily focused on designing UWB antenna elements and other microwave components for UWB wireless communications applications. The thesis starts with designing and implementing different new UWB disc monopole and hybrid anten-nas with discussions covering their operation, electrical behavior and performance. An-tennas are developed using microstrip technology to achieve low profile and compatibil-ity with printed circuit board (PCB) technology. Different techniques for obtaining a bandstop function in the 5.0-6.0 GHz frequency band to avoid interference with other ex-isting wireless local area network (WLAN) systems are numerically and experimentally presented. A UWB feed network prototype based on a modified two-section Wilkinson power divider is then developed. The designed feed network has been used in construct-ing two-element and four-element antenna arrays. The two-element antenna array has a total directive gain of about 5.5--8.5 dBi within the whole UWB frequency band while for the four-element antenna array, the achieved total directive gain is about 7.5--11.5 dBi. Two different UWB slot-coupled microstrip-to-microstrip vertical transitions are also addressed. The proposed transitions utilize trapezoidal- and butterfly-shaped mi-crostrip patches at the top and bottom layers. The broadside coupling between microstrip-coupled patches is achieved by cutting a rectangular-shaped slot in the mid-layer ground plane. The designed transitions are used to develop 3dB/90° hybrid couplers with good return loss, insertion loss, coupling and isolation characteristics across the desired fre-quency range. Then two different 45° phase shifters are developed to be used in building 4 x 4 Butler matrices for UWB beamforming applications. Finally, two compact and inexpensive multiple beamforming network (M-BFN) prototypes are developed. The developed microwave components using multi-layer mi-crostrip PCB technology are used to design 4 x 4 Butler matrices. These matrices avoid using any crossing lines or crossovers and exhibit large bandwidth for UWB applications. To validate the proposed design, experimental prototypes of the proposed 4 x 4 matrices are designed, fabricated and tested. A four patch antenna array is connected to these ma-trices to form multiple beamforming array systems. Simulations are carried out on these beamforming systems and the obtained radiation characteristics are also presented and discussed.

Download or read book The Art and Science of Ultrawideband Antennas Second Edition written by Hans G. Schantz and published by Artech House. This book was released on 2015-06-01 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive treatment of ultrawideband (UWB) antennas and time-domain microwave engineering serves as an invaluable practical reference for anyone involved in antenna and RF design work. This authoritative volume enables readers to select the proper UWB antennas for their applications, design and analyze UWB antennas, and integrate these antennas in an RF system. By applying time-domain thinking to problems of practical interest, the reader will not only learn how to build and analyze antennas, but also understand them at the most fundamental level. This second edition is updated and expanded throughout, providing readers with a history of antennas, numerous new problem sets and worked examples, along with new information on plotting time-domain field lines, time-domain reflectometry, matching techniques, and more. This book also addresses system issues like spectral control and antenna efficiency.

Download or read book Band Notch Characteristics in Ultra Wideband Antennas written by Taimoor Khan and published by CRC Press. This book was released on 2021-06-08 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprehensively reviews ultra-wideband (UWB) and UWB multi-input multi-output (MIMO) antennas with band-notched characteristics, with a focus on interference cancellation functionality. The book is organized into seven chapters that cover single band, dual band, and multi band-notched UWB antennas, followed by band-notched characteristics in UWB (MIMO) antennas. Further, it explains the mechanism of reconfigurability and tunability in band-notched UWB antennas, including advanced applications of UWB systems. Overall, it covers different techniques of canceling the electromagnetic interference in UWB in a concise volume. Features Provides a comprehensive presentation of avoiding interference in UWB systems Reviews state of the art literature related to UWB antennas, filtennas, and various reconfigurable technologies Explains different techniques for producing band-notch characteristics in UWB systems Includes discussion on historical perspectives of UWB technology Consolidates different research activities carried out on the electromagnetic interference cancellation techniques in the UWB communication systems Band-Notch Characteristics in Ultra-Wideband Antennas is aimed at researchers and graduate students in electrical and antenna engineering. Taimoor Khan has been an Assistant Professor at the Department of Electronics and Communication Engineering, National Institute of Technology Silchar since 2014. In addition to this, Dr. Khan has also worked as a Visiting Assistant Professor at Asian Institute of Technology Bangkok, Thailand during September–December, 2016. His active research interests include Printed Microwave Circuits, Electromagnetic Bandgap Structures, Ultra-wideband Antennas, Dielectric Resonator Antennas, Ambient Microwave Energy Harvesting, and Artificial Intelligence Paradigms in Electromagnetics. Dr. Khan has successfully guided three Ph.D. theses, and is supervising six Ph.D. students. He has published over 75 research articles in well-indexed journals and in world-renowned conference proceedings. Currently, he is executing three funded research projects, including two international collaborative SPARC and VAJRA research projects. In September 2020, Dr. Khan has been awarded a prestigious national IETE-Prof SVC Aiya Memorial Award for the year 2020. Yahia M. M. Antar has been a Professor at the Department of Electrical and Computer Engineering, Royal Military College of Canada since 1990. He served as the Chair of CNC, URSI from 1999 to 2008, Commission B from 1993 to 1999, and has a cross appointment at Queen’s University in Kingston. He has authored and co-authored over 250 journal papers, several books and chapters in books, over 500 refereed conference papers, holds several patents, has chaired several national and international conferences, and has given plenary talks at many conferences. Dr. Antar is a fellow of the Engineering Institute of Canada, the Electromagnetic Academy, and an International Union of Radio Science (URSI). He was elected by the URSI to the Board as the Vice President in 2008 and in 2014, and to the IEEE AP AdCom in 2009. In 2011, he was appointed as a member of the Canadian Defence Advisory Board (DAB) of the Canadian Department of National Defence. He serves as an Associate Editor for many IEEE and IET Journals, and as an IEEE-APS Distinguished Lecturer. Presently, he is working as President-Elect for IEEE Antenna and Propagation Society for the year 2020.

Download or read book Ultra Wideband written by Mohammad Abdul Matin and published by BoD – Books on Demand. This book was released on 2012-10-03 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Multifunctional and Multiband Planar Antennas for Emerging Wireless Applications written by Jayshri Kulkarni and published by CRC Press. This book was released on 2023-12-19 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes designed miniaturized monopole antennas for laptop computers with dual/triple band operations, performance enhancement, wider bandwidth, and increased data rate Explores the design of equivalent circuit diagrams of the proposed antenna. Presents integration of designed antennas into laptop for the validation of desired outcome Identifies and discusses technical challenges and new results related to the design of 5G/WLAN antennas Contains graphical illustration, design steps, detail analysis of each step along with proper justification

Download or read book Compact Planar Uwb Antennas for Wireless Device Applications written by Li Liu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Compact Planar UWB Antennas for Wireless Device Applications" by Li, Liu, 劉荔, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: 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 2628 mm2and 3039.3mm2are 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 2640 〖mm〗 DEGREES2, 2138 〖mm〗 DEGREES2, and 2236 〖mm〗 DEGREES2 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. DOI: 10.5353/th_b5334867 Subjects: Wireless communication systems - Equipment and supplies - Design and construction Ultra-wideband antennas

Download or read book Analysis and Modeling of Multiple Antennas in Ultra Wideband written by Raffaele D'Errico and published by . This book was released on 2008 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra Wide Band (UWB) is a wireless communication technology that employs a huge bandwidth, typically from hundreds of MHz up to several GHz. Research activities in UWB have experienced a continuous growth over the past decade. It is well known that, in traditional narrow-band communications, multiple antenna systems offer attractive aspects in wireless communications by means of Multiple-Input-Multiple-Output (MIMO) techniques, that either give out high channel capacities through spatial multiplexing, or offer an increase of link robustness, by taking advantage of antenna diversity at both ends of the link. A large number of scientific contributions have been published in the last years on UWB communications and narrow-band multiple antenna systems (MAS), but the literature on UWB combined with multiple antennas is still poor, especially on electromagnetic aspects. One of the most challenging issues is size reduction of the MAS. In practical applications, arrays should be compact in order to be incorporated in radio devices. Obviously, by reducing the single antenna size or the inter-antennas distance, it is possible to minimize the overall system dimension. On the other hand, the mutual coupling increases for closely spaced sensors, which can detrimentally modify the system performance. Thus, radiation, and distortion characteristics of the single radiator are altered because of the presence of other antennas. In this thesis we address the issue of the UWB multiple antenna design and assessment, by highlighting the influence of the interaction between close radiators, and by modelling it. In Chapter 1 we present an overview of UWB technology, by focusing on the main aspects of the physical layer. In chapter 2 we present a variety of single UWB antenna designs. We focus on the major features of UWB antenna characterization and the influence of antenna distortion. These antennas will be employed as single element composing the multiple antenna system in the subsequent work. In chapter 3 we present a UWB multiple antenna measurement campaign carried out in a anechoic chamber. The aim is to characterize UWB multiple antennas for different array topologies, inter-elements distances and single element designs. In chapter 4 we present a general method based on the definition of a scattering coefficient to predict the effects of the passive radiators within the multiple antenna system. The method has the advantage to avoid the use of a full electromagnetic simulation (or measurement) of the array. Moreover a statistical model of the scattering within UWB multiple antennas is introduced and presented for a class of UWB monopoles. The model is based on poles extraction of the scattering coefficient by means of the Generalized Matrix Pencil method. In chapter 5 we present a UWB channel measurement campaign in the 2-10 GHz band intended to quantitatively evaluate the improvements obtained through multiple antennas in UWB systems. To this aim an analysis of antenna diversity with previously characterized arrays is presented with emphasis on the differences between virtual real interacting compact arrays. The impact of the signal bandwidth on spatial multiplexing in the case of pulse based physical layer schemes, in the measured multiple antenna channels. This work has been carried out at ENSTA-Paris Tech and the University of Bologna, in the scope of the European FP6 project PULSERS Phase II.

Download or read book Broadband Planar Antennas written by Zhi Ning Chen and published by John Wiley & Sons. This book was released on 2006-05-01 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing demand for wireless communications has revolutionised the lifestyle of today’s society and one of the key components of wireless technology is antenna design. Broadband planar antennas are the newest generation of antennas boasting the attractive features required, such as broad operating bandwidth, low profile, light weight, low cost and ease of integration into arrays or Radio Frequency (RF) circuits, to make them ideal components of modern communications systems. Research into small and broadband antennas has been spurred by the rapid development of portable wireless communication devices such as cell phones, laptops and personal digital assistants. This all-encompassing volume, Broadband Planar Antennas: Design and Applications, systematically describes the techniques for all planar antennas from microstrip patch antennas, suspended plate antennas and planar inverted-L/F antennas to planar dipole antennas. Also discussed are some of the most recent outcomes such as broadband antenna issues in promising ultra-wideband applications. Clearly describes the fundamentals of planar antennas and categorises them according to their radiation characteristics Introduces the advanced progress in broadband planar antennas for modern wireless communications Includes a wealth of case studies, design guidelines, figures and tables This text is essential reading for antenna, RF and microwave engineers and manufacturers within the telecommunications industry. Its highly accessible approach will also appeal to researchers, postgraduate students and academic lecturers.