Download or read book Reconfigurable Antennas for High Data Rate Multi Beam Communication Systems written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-04 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.Bernhard, Jennifer T. and Michielssen, EricGlenn Research CenterANTENNA DESIGN; ANTENNA COMPONENTS; MICROSTRIP ANTENNAS; SPIRAL ANTENNAS; ANTENNA ARRAYS; PLANAR STRUCTURES; MICROELECTROMECHANICAL SYSTEMS; SWITCHES; ANTENNA RADIATION PATTERNS

Download or read book Multifunctional Antennas and Arrays for Wireless Communication Systems written by Satish K. Sharma and published by John Wiley & Sons. This book was released on 2021-04-13 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: MULTIFUNCTIONAL ANTENNAS AND ARRAYS FOR WIRELESS COMMUNICATION SYSTEMS Offers an up-to-date discussion of multifunctional antennas and arrays for wireless communication systems Multifunctional Antennas and Arrays for Wireless Communication Systems is a comprehensive reference on state-of-the-art reconfigurable antennas and 4G/5G communication antennas. The book gives a unique perspective while giving a comprehensive overview of the following topics: Frequency reconfigurable antennas Pattern reconfigurable antennas Polarization reconfigurable antennas Reconfigurable antennas using Liquid Metal, Piezoelectric, and RF MEMS MIMO and 4G/5G wireless communication antennas Metamaterials and metasurfaces in reconfigurable antennas Multifunctional antennas for user equipments (UEs) Defense related antennas and applications Flat panel phased array antennas The book is a valuable resource for the practicing engineer as well as for those within the research field. As wireless communications continuously evolves, more and more functionally will be required, and thus multifunctional antennas and RF systems will be necessary. These multifunctional antennas will require a degree of reconfigurability, and this book discusses various methods which enable this. The main topics of frequency, pattern, and polarization reconfigurability is first discussed. Methods utilizing unique materials and devices, both real and artificial are discussed. The book also delves into 4G/5G antennas as it relates to MIMO, and millimeter-wave phased arrays. Finally, there is a section on defense related multifunctional RF antenna systems.

Download or read book Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications written by Yingjie Jay Guo and published by John Wiley & Sons. This book was released on 2021-10-20 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications Reviews advances in the design and deployment of antenna arrays for future generations of wireless communication systems, offering new solutions for the telecommunications industry Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications addresses the challenges in designing and deploying antennas and antenna arrays which deliver 6G and beyond performance with high energy efficiency and possess the capability of being immune to interference caused by different systems mounted on the same platforms. This timely and authoritative volume presents innovative solutions for developing integrated communications networks of high-gain, individually-scannable, multi-beam antennas that are reconfigurable and conformable to all platforms, thus enabling the evolving integrated land, air and space communications networks. The text begins with an up-to-date discussion of the engineering issues facing future wireless communications systems, followed by a detailed discussion of different beamforming networks for multi-beam antennas. Subsequent chapters address problems of 4G/5G antenna collocation, discuss differentially-fed antenna arrays, explore conformal transmit arrays for airborne platforms, and present latest results on fixed frequency beam scanning leaky wave antennas as well as various analogue beam synthesizing strategies. Based primarily on the authors’ extensive work in the field, including original research never before published, this important new volume: Reviews multi-beam feed networks, array decoupling and de-scattering methods Provides a systematic study on differentially fed antenna arrays that are resistant to interference caused by future multifunctional/multi-generation systems Features previously unpublished material on conformal transmit arrays based on Huygen’s metasufaces and reconfigurable leaky wave antennas Includes novel algorithms for synthesizing and optimizing thinned massive arrays, conformal arrays, frequency invariant arrays, and other future arrays Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications is an invaluable resource for antenna engineers and researchers, as well as graduate and senior undergraduate students in the field.

Download or read book Reconfigurable Active and Passive Planar Antennas for Wireless Communication Systems written by Shiban Kishen Koul and published by Springer Nature. This book was released on 2022-10-14 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents state-of-the-art trends in reconfigurable active and passive planar antennas and their applications in wireless communication systems operating in the frequency band 5-6 GHz. Due to various key features such as multifunction antenna design, compactness, planar nature, and low cost, these technologies are becoming popular for current and future wireless applications. This book discusses different novel antenna designs and their working principles in detail. The modern and future wireless systems require wideband antennas to accommodate various channels in a single band or in separate bands. The carrier aggregation (CA) has been introduced in the modern wireless systems such as LTE-advanced systems and 5G./6G. In CA, a device can use several channels for transmission and reception. The used channels can exist in the same frequency band (intra-band CA) or in distinct bands (inter-band CA). To accommodate more channels, more bandwidth is required within the operating band. For portable devices, circularly polarized (CP) antennas are more advantageous over linearly polarized antennas since in CP antennas, there is low risk of misalignment and, hence encountering interference. Circularly polarized antenna also provides higher link reliability for the portable devices. To provide high data rates, more bandwidth is needed to accommodate more channels. Various multifunction, compact, and wideband antennas for plethora of applications are addressed in detail in this book. The scope of developing reconfigurable active antennas for application in beam switching, beam steering, wireless charging, security systems, etc., is described. This book concludes by giving glimpses of antenna requirements for future wireless communication systems.

Download or read book Reconfigurable Antennas written by Jennifer T. Bernhard and published by Morgan & Claypool Publishers. This book was released on 2007 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antennas are necessary and critical components of communication and radar systems. Making antennas reconfigurable so that their behavior can adapt with changing system requirements or environmental conditions can ameliorate or eliminate these restrictions and promises to provide additional levels of functionality for any system. If a single reconfigurable antenna could deliver the same functionality of more than one traditional single-purpose system, significant savings in cost, weight, volume, and maintenance/repair resources may be realizable.Reconfigurable Antennas describes in detail the critical parameters for antenna operation, as well as possible methods for achieving reconfigurability in each of these parameters. It also discusses practical issues surrounding the implementation of reconfigurable antennas, including feed methods, bias line design and implementation, and component selection. Finally, the book offers a view of the future of reconfigurable antennas and their promise to expand and improve system functionality in a range of different operating scenarios.

Download or read book Multifunctional Reconfigurable Antennas and Arrays Operating at 60 Ghz Band written by Abdurazag Mohamed Khalat and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To meet the ever increasing demand of high data rate, millimeter-wave (mm-wave) wireless communication has become an area of intense research due to the capability of offering very broad bandwidth. However, the propagation losses increase as a function of operation frequency. Therefore, there is need for antenna systems with high gain and beam-steering capability at elevated frequencies, which comes at the expense of high cost and increased complexity. This dissertation demonstrates the design, micro-fabrication, and characterization of two different antennas and two different antenna arrays. A broadband patch antenna operating within (57-66) GHz band, which works as a building block to create a multifunctional reconfigurable antenna (MRA) that is capable of beam steering in three directions pertaining to Îı 8́8{-30℗ʻ, 0℗ʻ, 30℗ʻ}; ÎŒ=90℗ʻ. These standalone antennas were then put in a linear formation to create a 2x8 planar array and a 4x1 multifunctional reconfigurable antenna array (MRAA) to increase the gain further and to offer wider bandwidth. The proposed novel MRA and MRAA possess variable element factors, which potentially can feature as the main building blocks of mm-wave reconfigurable wireless communication systems with reduced cost and complexity.

Download or read book Enhancing Multi User Wireless Networks with Pattern Reconfigurable Antennas written by Simon Begashaw and published by . This book was released on 2019 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosive demand for high data rates and the need ubiquitous wireless connectivity has led to the phenomenon of network densification, the deployment of large number of base station within a geographic area. Since the radio spectrum is limited, wireless transmissions need to share a common resource which results in interference. Interference in turn creates a bottleneck on the communication rate. Recently three breakthroughs have been made to increase the capacity of wireless networks while mitigating interference : multiple input multiple output (MIMO) beamforming, interference alignment (IA) and pattern reconfigurable antennas (PRA). While a great deal of progress has been made on understanding each individually, relatively little is known about how to use these techniques in combination to increase system performance. In this dissertation, we analyze and experimentally evaluate how these new technologies can be leveraged to enhance the rate performance of communication networks. Specifically, we address three problems: i) enhancing multi-user MIMO performance with PRA, ii) improving IA performance with PRA-based antenna selection, and iii) enabling practical blind IA with PRA. To understand the impact PRAs on MU-MIMO and IA, it is necessary to evaluate their performance through measurements. Simulation-based studies often reiterate over set of simplistic channel models and unrealistic assumptions. This dissertation focuses on a measurement-based evaluation approach. For each of these problems, a hardware testbed implementation and measurement methodology is developed for evaluating the performance of the aforementioned technologies through efficient and repeatable experiments. The first two major contributions of this dissertation focus on multi-user MIMO (MU-MIMO) and IA. While the theoretical rate gains of MU-MIMO and IA are substantial, the performance gains in practical systems and measured channels have been limited. One of the key limiting factors are spatially correlated user channels. In this work, we propose MU-MIMO and IA transmission schemes that leverage the pattern diversity provided by PRAs to mitigate the effects of spatial correlation in wireless channels. PRAs are capable of dynamically adjusting their radiation pattern, providing an additional degree of freedom that can be exploited to improve MU-MIMO and IA performance by treating the array configuration and radiation characteristics as additional components in the joint optimization of adaptive system parameters. We quantify the benefits of pattern diversity on the rate performance of MU-MIMO and IA systems through extensive measurements. Furthermore, we develop efficient antenna mode selection algorithms to realize those benefits without increasing the system complexity or overhead, making these techniques suitable for practical implementation. The third contribution of this dissertation focuses on a transmission technique known as blind IA. In contrast to MU-MIMO and conventional IA, blind IA is signaling scheme that suppresses interference in multi-user systems, without the knowledge of channel state information at the transmitter (CSIT). The key to performing IA without CSIT is the use of PRAs that are capable of dynamically switching among a fixed number of radiation patterns to introduce artificial fluctuations in the channel. In this dissertation, we develop a novel implementation of a blind IA system on a software defined radio platform where each of the receivers is equipped with a PRA. Our work provides the first experimental evaluation of PRA-based blind IA schemes and demonstrates significant gains in rate and reliability over traditional orthogonal transmission schemes such as TDMA.

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 Reconfigurable Antennas for Public Safety and Wireless Gigabit Alliance Applications written by Hema Swaroop Mopidevi and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this research is to develop a new type of antenna, called reconfigurable antenna, which can replace multiple antennas required to enhance the effectiveness of a robust communication system. A recongurable antenna integrated with switching elements can dynamically change its properties, namely, frequency of operation, radiation pattern (the three-dimensional coverage of antenna), and polarization (the electrical orientation of the antenna). Depending on the requirement, a single antenna can function as multiple an- tennas, therefore, the name Multi-functional Recongurable Antenna (MRA). United States (US) Public Safety (PS) responders (police, re-ghters, emergency medical services, etc.) can eectively respond to human-made or natural catastrophies if they are equipped with robust communication systems supported by MRA. Wireless implementations of computer accessories (wireless HDMI, wireless storage to external hard-drive, etc.) that require high speed data communication are supported by 60 GHz communications. Equipping these devices with MRA could further increase the speed of communication, thereby resulting in a robust communication. In this work, pin-diodes and Micro Electro Mechanical Switches (MEMS) are integrated on the MRAs to reconfigure (dynamically change) its properties namely frequency and radiation pattern. An MRA capable of operating over 220, 470, 800, 4900 MHz PS bands is designed, manufactured, tested, and characterized. Another MRA capable of changing its radiation pattern over 4.94-4.99 GHz band is designed, manufactured, tested, and characterized. The design of radiation pattern recongurable MRA and Multi-functional Reconfigurable Antenna Array (MRAA) for 60 GHz communication is also accomplished. The MRAA is designed in order to enhance the MRA's capability to receive or transmit more power.

Download or read book Antenna Analysis and Design for MIMO Systems with Emphasis on Reconfiguration written by Sahaya Kulandai Raj Joseph and published by Cuvillier Verlag. This book was released on 2012-08-06 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract The MIMO (Multiple Input Multiple Output) technology uses multiple antennas at the transmitter and at the receiver of a wireless communication system to improve the data rate. It exploits the multipath propagation of the signals radiated by the antennas of the transmitter. When the channel gains are correlated, the capacity gains are reduced. In this thesis, spatial correlation between the signals received by the dipole elements which are arranged as a uniform rectangular array is analytically found. It was found that the spatial correlation tends to be lower for certain antenna spacings when the mutual coupling is considered. When the elevation spread and the azimuth spread of the incoming waves decrease, the correlation of the channel gains increases. It has been demonstrated that a MIMO system equipped with reconfigurable antennas as elements can be made to shape the channel in order to obtain a channel conducive for MIMO. Through a ray tracing software, it has shown that the capacity offered by a MIMO system employing reconfigurable antennas is higher than that of omnidirectional antennas. In this context, the thesis proposes three different reconfigurable antennas. A beam reconfigurable three layer antenna was designed, fabricated and characterized. This fabricated antenna works as designed and simulated. As it is based on the Yagi antenna concept, the radiation behavior is explained using the Yagi antenna. This antenna can tilt its beam in the H-plane of the antenna in two directions. The second proposed antenna is a pattern and polarization reconfigurable antenna. This is designed to reconfigure ist beam in four directions. Two of the beams will have the same polarization, while the other two beams will have a polarization orthogonal to that of the former. A simple model involving halfwave dipoles was created to explain the pattern tilt. The model was created by investigating the current distribution on the antennas. The third of the proposed reconfigurable antennas is based on planar dipoles. This antenna is made to tilt the beam in the E-plane of the antenna. As a step forward, the role of switched beam antennas as elements of MIMO was also investigated at 60 GHz. It has been found that the switched beam antennas can indeed provide capacity gains over the unidirectional antennas. For fixed broadband wireless access such as a microwave relay, LOS MIMO (Line Of Sight) has been proposed in the literature for high data rate. A 4 × 4 LOS MIMO technique employing alternatively polarized antennas was analyzed in this thesis using the condition number and the capacity expressions. These expressions were derived in this thesis using fundamental principles. It was found that the antenna spacing required for the alternatively polarization is less than that of the single polarization case Kurzfassung Die MIMO (Multiple Input Multiple Output)-Technologie verwendet mehrere Antennen auf der Sende- und Empfangsseite eines drahtlosen Kommunikationssystems, um die Datenrate zu steigern. Dabei wird die Mehrwegeausbreitung der von den Sendeantennen ausgestrahlten Signale ausgenutzt. Wenn die Kanalgewinne der verschiedenen Ausbreitungswege korreliert sind, ergibt sich nur eine geringe Vergrößerung der Kanalkapazität. Im Rahmen dieser Arbeit wird für die räumliche Korrelation von Signalen, die von Dipol-Elementen in einem rechteckförmigen Array empfangen werden, eine analytische Darstellung abgeleitet. Dabei lässt sich feststellen, dass die räumliche Korrelation für bestimmte Antennenabstände geringer wird, wenn die gegenseitige Verkopplung der Antennen berücksichtigt wird.Wenn die Breiten derWinkelverteilungen der einfallenden Signale in Elevation und Azimut abnehmen, erhöht sich hingegen die Korrelation der Kanalgewinne. In der Arbeit wird demonstriert, dass ein MIMO-System mit Hilfe von rekonfigurierbaren Antennen so ausgelegt werden kann, dass es den Übertragungskanal in einer für MIMO vorteilhaften Weise ausbildet. Mittels Raytracing konnte gezeigt werden, dass die gebotene Kanalkapazität bei einem System, das rekonfigurierbare Antennen einsetzt, höher ist als bei einem System, das omnidirektionale Antennen einsetzt. In diesem Kontext werden drei verschiedene rekonfigurierbare Antennen vorgeschlagen. Eine aus drei Lagen bestehende strahlschwenkende Antenne wurde entworfen, hergestellt und charakterisiert. Die realisierte Antenne verhält sich so, wie es Design und Simulation erwarten lassen. Da sie auf dem Konzept der Yagi-Antenne basiert, wird auch ihre Abstrahlcharakteristik mit Hilfe der Yagi-Antenne beschrieben. Diese Antenne kann ihre Strahlkeule in der H-Ebene in zwei Richtungen schwenken. Bei der zweiten Antenne, die hier vorgeschlagen wird, kann sowohl die Strahlrichtung als auch die Polarisation verändert werden. Diese Antenne wurde so entworfen, dass ihre Strahlkeule in vier Richtungen konfiguriert werden kann. Zwei der Strahlrichtungen weisen dabei gleiche Polarisation auf, während die beiden anderen eine dazu senkrechte Polarisation besitzen. Die Strahlschwenkung wird mit Hilfe eines einfachen Modells auf der Grundlage von Halbwellen-Dipolen erklärt. Dazu wird die Stromverteilung auf den Antennen untersucht. Schließlich wird eine dritte Antenne vorgeschlagen, die auf planaren Dipolen basiert und deren Strahlkeule in der E-Ebene geschwenkt werden kann. In einem weiteren Schritt wird die Rolle von strahlschwenkenden Antennen als Teil eines MIMO-Systems bei 60 GHz untersucht und hierbei gefunden, dass strahlschwenkende Antennen im Vergleich zu unidirektionalen Antennen tatsächlich einen Kanalkapazitätsgewinn bieten. Für Zugangspunkte in festen drahtlosen Breitband-Übertragungssystemen wurde in der Literatur LOS MIMO (Line Of Sight, direkte Sichtverbindung) für hohe Datenraten vorgeschlagen. Ein 4 x 4 LOS-MIMO-Konzept mit unterschiedlich polarisierten Antennen wird in dieser Arbeit analysiert, wobei neben der Übertragungskapazität auch die Konditionierungszahl verwendet wird. Dazu werden diese Größen aus fundamentalen Prinzipien hergeleitet. Es hat sich gezeigt, dass der für die wechselnde Polarisation benötigte Antennenabstand kleiner ist als im Falle lediglich einer Polarisation.

Download or read book Reconfigurable Antenna Design and Analysis written by Mohammod Ali and published by Artech House. This book was released on 2021-05-31 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exciting new book focuses on the analysis and design of reconfigurable antennas for modern wireless communications, sensing, and radar. It presents the definitions of basic antenna parameters, an overview of RF switches and explains how to characterize their insertion loss, isolation, and power handling issues. Basic reconfigurable antenna building blocks, such as dipoles, monopoles, patches and slots are described, followed by presentations on frequency reconfigurable antennas, pattern reconfigurable antennas, and basic scanning antenna arrays. Switch biasing in an electromagnetic environment is discussed, as well as simulation strategies of reconfigurable antennas, and MIMO (Multiple Input Multiple Output) reconfigurable antennas. Performance characterization of reconfigurable antennas is also presented. The book provides information for the technical professional to design frequency reconfigurable, pattern reconfigurable, and MIMO antennas all relevant for modern wireless communication systems. Readers learn how to select switching devices, bias them properly, and understand their role in the overall reconfigurable antenna design. The book presents practical experimental implementation issues, including losses due to switches, materials, and EMI (Electromagnetic Interference) and shows how to address those.

Download or read book Capacity Enhancement by Pattern Reconfigurable Multiple Antenna Systems in Vehicular Applications written by Kowalewski, Jerzy and published by KIT Scientific Publishing. This book was released on 2020-06-08 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Antenna Design for Cognitive Radio written by Youssef Tawk and published by Artech House. This book was released on 2016-06-30 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This one-of-a-kind new resource presents cognitive radio from an antenna design perspective and introduces the concept of cognitive radio as a protocol that benefits from under-utilized regions of the spectrum. This book covers topics that govern the operation of a cognitive radio and discusses the use of reconfigurable antennas, reconfigurable filtennas, and MIMO antennas for cognitive radio. The analysis and design of different antenna systems are presented, compared and evaluated. New approaches to improve spectrum efficiency are explored by demonstrating how to design software controlled cognitive radio antenna systems. This new resource shows how to communicate using either interweave or underlay cognitive radio and demonstrates the benefits of designing appropriate sensing and communicating antennas. The first part of the book introduces the basic concept of cognitive radio and discusses the difference between cognitive radio and software defined radio from the RF system 's perspective. The second part of the book discusses the main antenna design requirements, procedures and challenges for cognitive radio. The third part of the book introduces new trends in cognitive radio implementation such as the implementation of MIMO antennas on cognitive radio, the use of machine learning techniques to optimize the performance of a cognitive radio environment, and the implementation of cognitive radar and cognitive radio in space.

Download or read book Design of Reconfigurable Antennas Using Graph Models written by Joseph Costantine and published by Springer Nature. This book was released on 2022-06-01 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This lecture discusses the use of graph models to represent reconfigurable antennas. The rise of antennas that adapt to their environment and change their operation based on the user's request hasn't been met with clear design guidelines. There is a need to propose some rules for the optimization of any reconfigurable antenna design and performance. Since reconfigurable antennas are seen as a collection of self-organizing parts, graph models can be introduced to relate each possible topology to a corresponding electromagnetic performance in terms of achieving a characteristic frequency of operation, impedance, and polarization. These models help designers understand reconfigurable antenna structures and enhance their functionality since they transform antennas from bulky devices into mathematical and software accessible models. The use of graphs facilitates the software control and cognition ability of reconfigurable antennas while optimizing their performance. This lecture also discusses the reduction of redundancy, complexity and reliability of reconfigurable antennas and reconfigurable antenna arrays. The full analysis of these parameters allows a better reconfigurable antenna implementation in wireless and space communications platforms. The use of graph models to reduce the complexity while preserving the reliability of reconfigurable antennas allow a better incorporation in applications such as cognitive radio, MIMO, satellite communications, and personal communication systems. A swifter response time is achieved with less cost and losses. This lecture is written for individuals who wish to venture into the field of reconfigurable antennas, with a little prior experience in this area, and learn how graph rules and theory, mainly used in the field of computer science, networking, and control systems can be applied to electromagnetic structures. This lecture will walk the reader through a design and analysis process of reconfigurable antennas using graph models with a practical and theoretical outlook.

Download or read book Pattern Diversity Characterization of Reconfigurable Antenna Arrays for Next Generation Wireless Systems written by George Dimanson Sworo and published by . This book was released on 2015 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of multi-antenna technology in wireless radio communications has attracted tremendous attention due to its potential to increase data rates without requiring additional bandwidth and transmission power. This has been driven by the burgeoning demand for high data rates and the need for instantaneous and ubiquitous access to information. It is therefore no surprise that current and future generation wireless standards such as LTE and WiMAX have adopted the use of adaptive multi-antenna systems also known as adaptive Multiple Input and Multiple Output (MIMO) as their de facto transmission technology. In this thesis work, we focus on the design of a smart wireless antenna system, and the study of relevant techniques that enable us to reap the benefits of their deployment in small wireless devices with MIMO capability. Specifically, we employ a new class of adaptive antenna systems known as Reconfigurable Antenna Systems (RAS) for portable devices. These antennas are capable of dynamically changing their electrical and radiation characteristics to suit the conditions of the wireless channel. The changing radiation patterns lead to pattern diversity gains that improve system performance. This is in contrast to conventional non-reconfigurable arrays which depend on signal processing techniques such as antenna grouping and beamforming to achieve performance gains. However, despite the demonstrable system-level performance benefits of RAS in adaptive MIMO, few of these antennas have been adopted and integrated in state-of-the-art wireless standards. Their usage has been partly inhibited by the prohibitive costs of implementation and operation in a real wireless infrastructure. As part of this thesis research effort we attempt to integrate these new antennas into a cost-effective real wireless MIMO testbed for use in current generation technologies. The solution integration is carried-out through the use of readily available software-defined radio frameworks. We first design, analyze and characterize the pattern diversity in RAS antenna arrays that resonate at frequencies suitable for 4G applications. We then study the benefits of pattern diversity obtained from RAS arrays over conventional space diversity approaches such as antenna grouping and beamforming. This dissertation also presents low-complexity adaptive physical layer models and algorithms to exploit the benefits of RAS array integration in MIMO wireless systems. We implement these algorithms in software-defined radio frameworks, experimentally test, and benchmark them against other established approaches in literature. And finally, integrate and test these RAS array design prototypes as part of the MIMO wireless system that leverages a state-of-the-art wireless base station and mobile terminals.

Download or read book Antenna Systems for Modern Wireless Devices written by Shiban K. Koul and published by Springer Nature. This book was released on with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modern Printed Circuit Antennas written by Hussain Al-Rizzo and published by BoD – Books on Demand. This book was released on 2020-10-28 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents in-depth information on a variety of the latest developments in modern printed-circuit antennas written by several prominent authors in the field. This book consists of nine chapters covering a wide range of recent research topics. The topics covered include low-profile metamaterial-based adaptive beamforming techniques, high performance meta-surface antennas, fractal antennas, reconfigurable antennas for 5G systems operating at 60 GHz, radiation pattern synthesis of planar arrays using parasitic patches fed by a small number of active elements, decoupled and de-scattered monopole MIMO antenna arrays with orthogonal radiation patterns, ultra-wide band antennas with defected ground plane and microstrip line fed for Wi-Fi/Wi-Max/DCS/5G/satellite communications, and design, fabrication, and characterization of wearable textile antennas with high body-antenna isolation.