This thesis focuses on two areas - the development of miniature plastic lasers that can be powered by LEDs, and the application of these lasers as highly sensitive sensors for vapours of nitroaromatic explosives (e.g. TNT). Polymer lasers are extremely compact visible lasers; the research described in the thesis is groundbreaking, driving forward the technology and physical understanding to allow these lasers to be routinely pumped by a single high-power LED. A notable advance in the work is the demonstration of nanoimprinted polymer lasers, which exhibit the world's lowest pump threshold densities by two orders of magnitude. The thesis also advances the application of these compact, novel lasers as highly sensitive detectors of explosive vapours, demonstrating that rapid detection can be achieved when microporous polymers are used. This work also demonstrates a prototype CMOS-based microsystem sensor for explosive vapours, exploiting a new detection approach.

This book investigates the design of devices, systems, and circuits for medical applications using the two recently established frequency bands: ultra-wideband (3.1-10.6 GHz) and 60 GHz ISM band. These two bands provide the largest bandwidths available for communication technologies and present many attractive opportunities for medical applications. The applications of these bands in healthcare are wireless body area network (WBAN), medical imaging, biomedical sensing, wearable and implantable devices, fast medical device connectivity, video data transmission, and vital signs monitoring. The recent technological advances and developments proposed or used in medicine based on these two bands are covered. The book introduces possible solutions and design techniques to efficiently implement these systems in medical environment. All individual chapters are written by leading experts in their fields. Contributions by authors are on various applications of ultra-wideband and the 60 GHz ISM band including circuit implementation, UWB and 60 GHz signal transmission around and in- body, antenna design solution, hardware implementation of body sensors, UWB transceiver design, 60 GHz transceiver design, UWB radar for contactless respiratory monitoring, and ultra-wideband based medical Imaging. The book will be a key resource for medical professionals, bio-medical engineers, and graduate and senior undergraduate students in computer, electrical, electronic and biomedical engineering disciplines.

The aim of this book is to serve as a design reference for students and as an up-to-date reference for researchers. It also acts as an excellent introduction for newcomers to the field and offers established rf/microwave engineers a comprehensive refresher. The content is roughly classified into two - the first two chapters provide the necessary fundamentals, while the last three chapters focus on design and applications. Chapter 2 covers detailed treatment of transmission lines. The Smith chart is utilized in this chapter as an important tool in the synthesis of matching networks for microwave amplifiers. Chapter 3 contains an exhaustive review of microstrip circuits, culled from various references. Chapter 4 offers practical design information on solid state amplifiers, while Chapter 5 contains topics on the design of modern planar filters, some of which were seldom published previously. A set of problems at the end of each chapter provides the readers with exercises which are compiled from actual university exam questions. An extensive list of references is available at the end of each chapter to enable readers to obtain further information on the topics covered.

This book describes and illustrates the application of several asymptotic methods that have proved useful in the authors' research in electromagnetics and antennas. We first define asymptotic approximations and expansions and explain these concepts in detail. We then develop certain prerequisites from complex analysis such as power series, multivalued functions (including the concepts of branch points and branch cuts), and the all-important gamma function. Of particular importance is the idea of analytic continuation (of functions of a single complex variable); our discussions here include some recent, direct applications to antennas and computational electromagnetics. Then, specific methods are discussed. These include integration by parts and the Riemann-Lebesgue lemma, the use of contour integration in conjunction with other methods, techniques related to Laplace's method and Watson's lemma, the asymptotic behavior of certain Fourier sine and cosine transforms, and the Poisson summation formula (including its version for finite sums). Often underutilized in the literature are asymptotic techniques based on the Mellin transform; our treatment of this subject complements the techniques presented in our recent Synthesis Lecture on the exact (not asymptotic) evaluation of integrals.

Recently, there has been interest by regulators, the public and the manufacturers of wireless devices in the issues relating to the safety of radio frequency (RF) energy. These issues require an understanding of the scientific underpinnings of both physics of RF energy and cellular biology. This book is designed to provide precisely such cross-functional expertise. The editors of this book intend to provide a reliable source for a sound scientific understanding of the issues and to stimulate future scientific advances in this area. Therefore, the audience for this book includes such diverse groups as scientists, governmental policy-makers and regulatory bodies, representatives of industry and the public at large.

This book unites two different technologies: parasitic antenna arrays driven via analogue circuits that control the electromagnetic waves generated by the antenna array; and MIMO technology for multi-antenna arrays, typically driven by digital techniques in the baseband domain. The combination of these two technologies has revealed a novel functionality that breaks through the conventional MIMO paradigm, allowing MIMO transmission over the air with the use of antenna arrays that may consist of only a single active element, that is surrounded by a number of passive neighboring antennas. The contributions in the book show the capability of such systems to also perform MIMO transmission. This fact holds the potential of revolutionizing the way small-form wireless terminals operate and seems to set the scene for a win-win situation, achieving MIMO transmission with very small and cheap antenna arrays. The book is structured to provide a well-rounded treatment of the various facets of this newly discovered wireless communication capability. All relevant technical angles, ranging from information theoretic to electromagnetic considerations; from analogue circuit to digital baseband control for signal generation; and from channel modeling to communication theoretic aspects are taken into account. A good balance between theory, practical considerations and over-the-air experimentation is proposed and reflected in the chapter outline. Finally, a discussion and early evidence related to potential applications as well as the relevance to current and upcoming wireless standards is provided.

A frequency synthesizer is one of the most critical building blocks in any wireless transceiver system. Its design is getting more and more challenging as the demand for low-voltage low-power high-frequency wireless systems continuously grows. As the supply voltage is decreased, many existing design techniques are no longer applicable. This book provides the reader with architectures and design techniques to enable CMOS frequency synthesizers to operate at low supply voltage at high frequency with good phase noise and low power consumption. In addition to updating the reader on many of these techniques in depth, this book will also introduce useful guidelines and step-by-step procedure on behaviour simulations of frequency synthesizers. Finally, three successfully demonstrated CMOS synthesizer prototypes with detailed design consideration and description will be elaborated to illustrate potential applications of the architectures and design techniques described. For engineers, managers and researchers working in radio-frequency integrated-circuit design for wireless applications.

Machine vision technology has revolutionised the process of automated inspection in manufacturing. The specialist techniques required for inspection of natural products, such as food, leather, textiles and stone is still a challenging area of research. Topological variations make image processing algorithm development, system integration and mechanical handling issues much more complex. The practical issues of making machine vision systems operate robustly in often hostile environments together with the latest technological advancements are reviewed in this volume. Features: - Case studies based on real-world problems to demonstrate the practical application of machine vision systems. - In-depth description of system components including image processing, illumination, real-time hardware, mechanical handling, sensing and on-line testing. - Systems-level integration of constituent technologies for bespoke applications across a variety of industries. - A diverse range of example applications that a system may be required to handle from live fish to ceramic tiles. Machine Vision for the Inspection of Natural Products will be a valuable resource for researchers developing innovative machine vision systems in collaboration with food technology, textile and agriculture sectors. It will also appeal to practising engineers and managers in industries where the application of machine vision can enhance product safety and process efficiency.

The book consists of two Volumes. The first (the preceding volume) is devoted to the general nonlinear theory of the hierarchical dynamic oscillative-wave systems. This theory has been called the theory of hi- archical oscillations and waves. Here two aspects of the proposed theory are discussed. The first aspects concern the fundamental nature and the basic c- cepts and ideas of a new hierarchical approach to studying hierarchical dynamic systems. A new hierarchical paradigm is proposed as a - sis of a new point of view of such types of systems. In turn, a set of hierarchical principles is formulated as the fundamental basis of this paradigm. Therein the self-resemblance (holographic) principle plays a key role here. An adequate mathematic description (factorization) of the proposed paradigm is carried out. The concepts of structural and dynamic (functional) operators are put into the basis of this descr- tion. Electrodynamics is chosen as a convenient basis for an obvious demonstration of some key points of the proposed new theory. The second aspect has a purely mathematical nature. It is related to the form of factorization (i.e., mathematical description) of hier- chical types of dynamic models, and discussion of the methods of their mathematical analysis. A set of the hierarchical asymptotic analytical- numerical methods is given as an evidence of the practical effectiveness of the proposed version of hierarchical theory.

Everybody is current in a world surrounded by computer. Computers determine our professional activity and penetrate increasingly deeper into our everyday life. Therein we also need increasingly refined c- puter technology. Sometimes we think that the next generation of c- puter will satisfy all our dreams, giving us hope that most of our urgent problems will be solved very soon. However, the future comes and il- sions dissipate. This phenomenon occurs and vanishes sporadically, and, possibly, is a fundamental law of our life. Experience shows that indeed 'systematically remaining' problems are mainly of a complex tech- logical nature (the creation of new generation of especially perfect - croschemes, elements of memory, etc. ). But let us note that amongst these problems there are always ones solved by our purely intellectual efforts alone. Progress in this direction does not require the invention of any 'superchip' or other similar elements. It is important to note that the results obtained in this way very often turn out to be more significant than the 'fruits' of relevant technological progress. The hierarchical asymptotic analytical-numerical methods can be - garded as results of such 'purely intellectual efforts'. Their application allows us to simplify essentially computer calculational procedures and, consequently, to reduce the calculational time required. It is obvious that this circumstance is very attractive to any computer user.

Microwave Integrated Circuits provides a comprehensive overview of analysis and design methods for integrated circuits and devices in microwave systems. Passive and active devices, and linear and non-linear circuits are covered with a final chapter detailing measurement and test techniques.

This volume contains the proceedings of the first ICASE/LaRC Work shop on Computational Electromagnetics and Its Applications conducted by the Institute for Computer Applications in Science and Engineering and NASA Langley Research Center. We had several goals in mind when we decided, jointly with the Elec tromagnetics Research Branch, to organize this workshop on Computa tional Electromagnetics ( CEM). Among our goals were a desire to obtain an overview of the current state of CEM, covering both algorithms and ap plications and their effect on NASA's activities in this area. In addition, we wanted to provide an attractive setting for computational scientists with expertise in other fields, especially computational fluid dynamics (CFD), to observe the algorithms and tools of CEM at work. Our expectation was that scientists from both fields would discover mutually beneficial inter connections and relationships. Another goal was to learn of progress in solution algorithms for electromagnetic optimization and design problems; such problems make extensive use of field solvers and computational effi ciency is at a premium. To achieve these goals we assembled the renowned group of speakers from academia and industry whose talks are contained in this volume. The papers are printed in the same order in which the talks were pre sented at the meeting. The first paper is an overview of work currently being performed in the Electromagnetic Research Branch at the Langley Research Center."

Rectenna Solar Cells discusses antenna-coupled diode solar cells, an emerging technology that has the potential to provide ultra-high efficiency, low-cost solar energy conversion. This book will provide an overview of solar rectennas, and provide thorough descriptions of the two main components: the diode, and the optical antenna. The editors discuss the science, design, modeling, and manufacturing of the antennas coupled with the diodes. The book will provide concepts to understanding the challenges, fabrication technologies, and materials required to develop rectenna structures. Written by experts in their specialized fields.

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.

This book describes the characterization of liquid crystal materials at microwave frequencies and the usage of these materials in reconfigurable planar antennas and in their electrical tunable components. It reports for the first time the realization of a two-dimensional electronic beam steering antenna and polarization agile planar antennas with liquid crystal display technology. It gives a detailed description of all the theoretical analyses, modeling and design methods that were involved in the realization of these devices as well as their validation using measurement of demonstrative prototypes. This book also shows that low profile, low cost, high gain, electronic beam steering and polarization agile antennas can be fabricated in larger sizes by using existing automated liquid crystal display manufacturing techniques. The innovative ideas and method described in this work represent a considerable advancement in the field of electronically reconfigurable antennas based on liquid crystal technology and are expected to draw significant interest in the future. Such antennas may become important, for example, in mobile terminals integrated into the body of laptops (in the cover) or of automobiles (in the rooftop), ships or boats, for which flat, low-profile and low-cost antennas are required.

The main theme of this book is the interaction of electrons with electromagnetic waves in the presence of periodic and quasi-periodic structures in vacuum, in view of applications in the design and operation of particle accelerators. The first part of the book is concerned with the textbook-like presentation of the basic material, in particular reviewing elementary electromagnetic phenomena and electron dynamics. The second part of the book describes the current models for beam-wave interactions with periodic and quasi-periodic structures. This is the basis for introducing, in the last part of the book, a number of particle and radiation sources that rest on these principles, in particular the free-electron laser, wake-field acceleration schemes and a number of other advanced particle accelerator concepts. This second edition brings this fundamental text up-to-date in view of the enormous advances that have been made over the last decade since the first edition was published. All chapters, as well as the bibliography, have been significantly revised and extended, and the number of end-of-chapter exercises has been further increased to enhance this book's usefulness for teaching specialized graduate courses.

This book provides a comprehensive synthesis of the theory and practice of photonic devices for networks-on-chip. It outlines the issues in designing photonic network-on-chip architectures for future many-core high performance chip multiprocessors. The discussion is built from the bottom up: starting with the design and implementation of key photonic devices and building blocks, reviewing networking and network-on-chip theory and existing research, and finishing with describing various architectures, their characteristics, and the impact they will have on a computing system. After acquainting the reader with all the issues in the design space, the discussion concludes with design automation techniques, supplemented by provided software.

Transformation electromagnetics is a systematic design technique for optical and electromagnetic devices that enables novel wave-material interaction properties. The associated metamaterials technology for designing and realizing optical and electromagnetic devices can control the behavior of light and electromagnetic waves in ways that have not been conventionally possible. The technique is credited with numerous novel device designs, most notably the invisibility cloaks, perfect lenses and a host of other remarkable devices. Transformation Electromagnetics and Metamaterials: Fundamental Principles and Applications presents a comprehensive treatment of the rapidly growing area of transformation electromagnetics and related metamaterial technology with contributions on the subject provided by a collection of leading experts from around the world. On the theoretical side, the following questions will be addressed: "Where does transformation electromagnetics come from?," "What are the general material properties for different classes of coordinate transformations?," "What are the limitations and challenges of device realizations?," and "What theoretical tools are available to make the coordinate transformation-based designs more amenable to fabrication using currently available techniques?" The comprehensive theoretical treatment will be complemented by device designs and/or realizations in various frequency regimes and applications including acoustic, radio frequency, terahertz, infrared, and the visible spectrum. The applications encompass invisibility cloaks, gradient-index lenses in the microwave and optical regimes, negative-index superlenses for sub-wavelength resolution focusing, flat lenses that produce highly collimated beams from an embedded antenna or optical source, beam concentrators, polarization rotators and splitters, perfect electromagnetic absorbers, and many others. This book will serve as the authoritative reference for students and researchers alike to the fast-evolving and exciting research area of transformation electromagnetics/optics, its application to the design of revolutionary new devices, and their associated metamaterial realizations.

The purpose of the package is to answer the question 'What is the radio field strength at a certain point?' when power is radiated from a transmit ting source. Because of the complexity of the question in general, it can only be answered at present in certain idealized situations. Nevertheless it is valuable to have quantitative data available for these situations. The package is divided into two parts. In the first of these, propagation in free space and over a flat earth are dealt with. In the second, propagation over a spherical earth is considered. In the free-space situation the power density of the signal in a given direction will fall as the inverse square of the distance from the source. For propagation from a transmitting source at an arbitrary height above a perfecdy conducting flat earth, the field strength at large distances can be 3 dB higher than in free space. With a finite conduc tivity earth, the field strength will be lower than this because of the power dissipation in the earth.

Do you need to know what signal type to select for a wireless application? Quickly develop a useful expertise in digital modulation with this practical guide, based on the author's experience of over thirty years in industrial design. You will understand the physical meaning behind the mathematics of wireless signals and learn the intricacies and tradeoffs in signal selection and design. Six modulation families and twelve modulation types are covered in depth, together with a quantitative ranking of relative cost incurred to implement any of twelve modulation types. Extensive discussions of the Shannon Limit, Nyquist filtering, efficiency measures and signal-to-noise measures are provided, radio wave propagation and antennas, multiple access techniques, and signal coding principles are all covered, and spread spectrum and wireless system operation requirements are presented.

The Advanced Study Institute on "Theoretical Aspects and New Developments in Magneto-Optics" was held at the University of Antwerpen (R.U.C.A.), from July 16 to July 28, 1979. The Institute was sponsored by NATO. Co-sponsors were: Agfa-Gevaert (Belgium), A.S.L.K. (Belgium), Bell Telephone Mfg. CO. (Belgium), Esso Belgium, Generale Bankmaatschappij (Belgium), General Motors (Belgium), I.B.M. (Belgium), Kredietbank (Belgium), Metallurgie Hoboken-Over pelt (Belgium), National Science Foundation (U.S.A). A total of 60 lecturers and participants attended the Institute. Scope of the Institute The magneto-optic phenomena are due to the change of the polarizability of a substance as a result of the splitting of the quantized energy bands. Most of these phenomena were discovered during the second half of this century. The understanding of the magneto-optical effects of all kinds, however, was brought by the advent of quantum mechanics, and since then important progress has been made in many fields of experimental methods and techniques.

This volume collects a a number of contributions on spontaneous symmetry breaking. Current studies in this general field are going ahead at a full speed. The book present review chapters which give an overview on the major break throughs of recent years. It covers a number of different physical settings which are introduced when a nonlinearity is added to the underlying symmetric problems and its strength exceeds a certain critical value. The corresponding loss of symmetry, called spontaneous symmetry breaking, alias self-trapping into asymmetric states is extensively discussed in this book.
The book presents both active theoretical studies of spontaneous symmetry breaking effects as well as experimental findings, chiefly for Bose-Einstein-Condensates with the self-repulsive nonlinearity, and also for photorefractive media in optics.

In the last decade, optically functionalized materials have developed rapidly, from bulk matters to structured forms. Now we have a rich variety of attractive advanced materials. They are applied to optical and electrical devices that support the information communication technology in the mid 21-th century. Accordingly, it is quite important to have a broad knowledge of the optical properties of advanced materials for students, scientists and engineers working in optics and related fields. This book is designed to teach fundamental optical properties of such advanced materials effectively. These materials have their own peculiarities which are very interesting in modern optical physics and also for applications because the concepts of optical properties are quite different from those in conventional optical materials. Hence each chapter starts to review the basic concepts of the materials briefly and proceeds to the practical use. The important topics covered in this book include: quantum structures of semiconductors, spintronics, photonic crystals, surface plasmons in metallic nanostructures, photonic metamaterials, liquid crystal materials, organic LED materials and magnet-optics.

This book is dedicated to the adoption of broadband microwave reflectometry (BMR)-based methods for diagnostics and monitoring applications. This electromagnetic technique has established as a powerful tool for monitoring purposes; in fact, it can balance several contrasting requirements, such as the versatility of the system, low implementation cost, real-time response, possibility of remote control, reliability, and adequate measurement accuracy. Starting from an extensive survey of the state of the art and from a clear and concise overview of the theoretical background, throughout the book, the different approaches of BMR are considered (i.e., time domain reflectometry - TDR, frequency domain reflectometry - FDR, and the TDR/FDR combined approach) and several applications are thoroughly investigated. The applications considered herein are very diverse from each other and cover different fields. In all the described procedures and methods, the ultimate goal is to endow them with a significant performance enhancement in terms of measurement accuracy, low cost, versatility, and practical implementation possibility, so as to unlock the strong potential of BMR.

Light emitting diodes (LEDs) are already used in traffic signals, signage lighting, and automotive applications. However, its ultimate goal is to replace traditional illumination through LED lamps since LED lighting significantly reduces energy consumption and cuts down on carbon-dioxide emission. Despite dramatic advances in LED technologies (e.g., growth, doping and processing technologies), however, there remain critical issues for further improvements yet to be achieved for the realization of solid-state lighting. This book aims to provide the readers with some contemporary LED issues, which have not been comprehensively discussed in the published books and, on which the performance of LEDs is seriously dependent. For example, most importantly, there must be a breakthrough in the growth of high-quality nitride semiconductor epitaxial layers with a low density of dislocations, in particular, in the growth of Al-rich and and In-rich GaN-based semiconductors. The materials quality is directly dependent on the substrates used, such as sapphire, Si, etc. In addition, efficiency droop, growth on different orientations and polarization are also important. Chip processing and packaging technologies are key issues. This book presents a comprehensive review of contemporary LED issues. Given the interest and importance of future research in nitride semiconducting materials and solid state lighting applications, the contents are very timely. The book is composed of chapters written by leading researchers in III-nitride semiconducting materials and device technology. This book will be of interest to scientists and engineers working on LEDs for lighting applications. Postgraduate researchers working on LEDs will also benefit from the issues this book provides.