Adaptive arrays are a radical departure from conventional thinking in antenna design, offering substantial improvements in performance over fixed pattern antennas in environments that include severe interference and jamming. They achieve this because they are designed to steer nulls automatically at noise sources of unknown or variable direction and generally to modify their beampatterns to optimise performance. Adaptive array processing is applicable in most systems that exploit wave propagation; typical uses being radar, active and passive sonar, radio communication links, and radio monitoring. Although sensors and hardware for different applications vary, the same optimality criteria are used throughout and similar algorithms may be employed. This book develops the concepts underlying the design of adaptive arrays from first principles and is directed at research workers and designers whose mathematical background requires refurbishment in the special techniques that have accumulated around the field, often to the obscuration of the simple basic ideas. The topics treated include: single multiple null steering; derivation of the weighting coefficients in an array that maximises signal to noise ratio; online algorithms for achieving these coefficients using gradient methods based on correlators and coefficient peterbation; direct estimation of optimum coefficients by covariance matrix inversion and recursive techniques; prevention of null steering at the desired source and control over the main lobe shape; minimisation of the number of variable coefficients in suboptimal implementations.

This comprehensive and self-contained resource conveniently combines advanced topics in electromagnetic theory, a high level of mathematical detail, and the well-established ubiquitous Method of Moments applied to the solution of practical wave-scattering and antenna problems formulated with surface, volume, and hybrid integral equations. Originating from the graduate-level electrical engineering course that the author taught at the Technical University of Eindhoven (NL) from 2010 to 2017, this well-researched two-volume set is an ideal tool for self-study. The subject matter is presented with clear, engaging prose and explanatory illustrations in logical order. References to specialized texts are meticulously provided for the readers who wish to deepen and expand their mastery of a specific topic. This book will be of great interest to graduate students, doctoral candidates and post-docs in electrical engineering and physics, and to industry professionals working in areas such as design of passive microwave/ optical components or antennas, and development of electromagnetic software. Thanks to the detailed mathematical derivations of all the important theoretical results and the numerous worked examples, readers can expect to build a solid and structured knowledge of the physical, mathematical, and computational aspects of classical electromagnetism. Volume 1 covers fundamental notions and theorems, static electric fields, stationary magnetic fields, properties of electromagnetic fields, electromagnetic waves and finishes with time-varying electromagnetic fields. Volume 2 starts with integral formulas and equivalence principles, then moves on to cover spectral representations of electromagnetic fields, wave propagation in dispersive media, integral equations in electromagnetics and finishes with a comprehensive explanation of the Method of Moments.

Time domain modeling is a fascinating world which brings together several complex phenomena and methods of essential interest to engineers. This book is a reference guide which discusses the most advanced time-domain modeling methods and applications in electromagnetics and electrical engineering.

The book starts by clearly explaining why time-domain modeling may be worth doing; then, it provides guidelines about why some choices must be made among the principal modeling approaches and next guides the reader through the state of the art in time domain modeling, concerning either numerical and analytical methods, and applications. Finally, it highlights areas for future time-domain modeling research.

The book is a collection of chapters written by leading research groups in the fields, following a logical development set out by the editor.

Topics covered include finite element methods in time domain with applications to low-frequency problems; transient analysis of scattering from composite objects using late-time stable TDIEs; the transmission-line modeling method, partial element equivalent circuit method in time-domain; unconditionally stable time-domain methods; time-domain linear macromodeling, analytical techniques for transient analysis; the application of the finite-difference time-domain (FDTD) technique to lightning studies; modeling of lightning and its interaction with overhead conductors; transient behaviour of grounding systems; and statistics of electromagnetic reverberation chambers and their simulation through time domain modeling.

Microwave filters are the basic building blocks of communication systems. These filters, having reliable and scalable filter topologies with and without tunable properties, are capable of controlling different frequency bands as well as their fractional bandwidth to meet different system needs. There have been significant advances in the synthesis and physical realisation of microwave filter networks, and the design and applications for communication systems. This edited book presents recent advances in planar filter design. It covers a wide range of different design types, technologies and applications for wireless, microwave, communications and radar systems. Written by academic professionals from around the world, this book offers a global perspective on the latest developments in this area. Advances in Planar Filters Design is essential reading for R&D engineers, specialists, research students and academics working on the topic of RF/microwave filters and related system applications and other specialists in RF/microwave engineering

Two alternative methods of aperture antenna analysis are described in this book.

Non-metallic materials and composites are now commonplace in modern vehicle construction, and the need to compute scattering and other electromagnetic phenomena in the presence of material structures has led to the development of new simulation techniques. This book describes a variety of methods for the approximate simulation of material surfaces, and provides the first comprehensive treatment of boundary conditions in electromagnetics. The genesis and properties of impedance, resistive sheet, conductive sheet, generalised (or higher order) and absorbing (or non-reflecting) boundary conditions are discussed. Applications to diffraction by numerous canonical geometries and impedance (coated) structures are presented, and accuracy and uniqueness issues are also addressed, high frequency techniques such as the physical and geometrical theories of diffraction are introduced, and more than130 figures illustrate the results, many of which have not appeared previously in the literature. Written by two of the authorities m the field, this graduate-level text should be of interest to all scientists and engineers concerned with the analytical and numerical solution of electromagnetic problems.

Bioelectromagnetics in Healthcare: Advanced sensing and communication applications is a collection of twelve invited chapters from international experts from the UK, Japan, Switzerland, and the United States of America. The book forms a cohesive architecture that covers the state-of-the-art in terms of sensing and communications with relevance to bioelectromagnetics in healthcare. The book provides a valuable insight into the current and future possibilities where electromagnetics engineers will need to keep improving radiofrequency device performance in terms of better efficiency, greater sensitivity, reduced unintended power absorption by the body, smaller size, and lower power consumption.

Topics covered include dielectric measurements, dosimetry for bioelectromagnetics, phantom recipes for implanted and wearable antenna applications, antennas for implants, electromagnetic coupling in biological media, electromagnetic resonators and metamaterials-based structures for chemical and biological sensing in body-centric wireless applications, bone fracture monitoring using implanted antennas, wearable antennas for sensing, epidermal and conformal electronics, radar for healthcare technology, therapeutic applications of electromagnetic waves, and optoelectronic sensing of physiological monitoring.

The book is aimed at electromagnetics engineers and advanced students in electromagnetics working on healthcare and medical applications.

Given that charge acceleration is the cause of all electromagnetic radiation, the question arises about where such acceleration occurs on objects typically modelled and analysed by electromagnetic engineers. Charge acceleration, as the cause of radiation from these typical kinds of objects (antennas, radars etc) is examined in this book on a quantitative basis.

The book describes new ways of modelling the actual distribution of EM radiation waves from its various sources. Unlike other books on EM it focuses on radiation, a fundamental property of electromagnetic fields, it does not follow the usual analytical kind of approach to be found in a book on electromagnetics. Rather than developing and presenting a formal theoretical foundation of electromagnetic theory, this book instead focuses on various aspects of EM radiation from a variety of perspectives.

The goal is to provide the reader with computational tools for determining quantitatively why and where radiation is emitted by antennas and scatterers. This is a unique approach which is of wide interest to the EM theoretical community.

A cognitive radio is a transceiver which is aware of its environment, its own technical capabilities and limitations, and those of the radios with which it may communicate; is capable of acting on that awareness and past experience to configure itself in a way that optimizes its performance; and is capable of learning from experience. In a real sense, a cognitive radio is an intelligent communications system that designs and redesigns itself in real time. Cognitive Radio Engineering is both a text and a reference book about cognitive radio architecture and implementation, intended for readers who want to design and build working cognitive radios. It takes the reader from conceptual block diagrams through the design and evaluation of illustrative prototypes. An important goal is to bridge the divide between radio engineers, who often have little experience with the computational resource and timing issues inherent in cognitive radios, and computer engineers who often are unaware of RF issues like dynamic range, intermodulation products, and acquisition time. Following a brief overview of cognitive radio history and a high-level look at cognitive radio operation, the book presents a detailed study of cognitive engine design and analysis. After treating RF subsystems the book considers computational platforms and computation issues in cognitive radios, followed by system integration, evaluation methods for cognitive radio, and cognitive radio design for networking. The book concludes with coverage of cognitive radio applications in communications.

Corrugated horns are widely used and highly efficient, especially in their use as feeds for microwave reflector antennas. This book is devoted to the theory and design of corrugated horns and scalar feeds and explains why hybrid mode feeds are ideal feeds for reflectors.