Download or read book A Reactively Loaded Aperture Antenna Array written by John Luzwick and published by . This book was released on 1976 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report considers an array of reactively loaded aperture antennas, specifically, an N element array of closely-spaced waveguide-backed rectangular slots. Only the center waveguide is fed and the other waveguides are short circuited to provide the reactive loads. The positions of the short circuits are chosen to obtain maximum antenna gain in some specified direction. By varying the positions of the short circuits a directive beam can be steered through 180 deg. space. Both seven and nine element arrays are considered explicitly. Feasibility for physical realization of the reactive loading is discussed. A computer program with operating instructions is included. (Author).

Download or read book A Solution for a Wide Aperture Reactively Loaded Antenna Array written by John Luzwick and published by . This book was released on 1977 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report considers an array of wide aperture reactively loaded antennas, specifically, an N element array of closely-spaced waveguide-backed rectangular slots radiating into a half-space region. Only the center slot is fed and the other slots are parasitically excited. The parasitic slots are reactively loaded by short-circuit waveguides. By varying the positions of the short circuits, a directive beam can be steered through 180 deg in space. The solution uses the moment method applied to the integral equation for the equivalent magnetic current in the aperture region and a numerical integration technique. Solutions for seven, nine, and fifteen element aperture arrays are given. A computer subroutine which generates the aperture halfspace admittance matrix is described and listed. (Author).

Download or read book A Study of a Reactively Loaded Finite Planar Rectangular Waveguide Antenna Array written by John Luzwick and published by . This book was released on 1979 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis of a general class of antenna arrays, specifically the reactively loaded parasitically excited waveguide-backed aperture antenna array, is presented. The antenna arrays considered have a single waveguide-fed aperture, no complex feed network to all of the apertures, and one reactive load (shorted waveguide) for each remaining aperture. By varying the position of the short circuits, a directive beam can be steered through 180 deg in space. Only partial control of the array characteristics is possible using this scheme. However, the simplicity of antenna feed design and ease of pattern control makes reactive loading attractive. The antenna arrays investigated have both linear and two dimensional lattices. Each antenna is characterized in terms of power gain, bandwidth, and match. Several examples of magnitude pattern synthesis are presented to show antenna pattern limitations for a given antenna geometry and excitation. In addition, an example using a double-frequency synthesis procedure is given for reshaping gain versus frequency characteristics in the endfire directions. In this direction, gain is higher and bandwidth lower than in other directions. The reactive loading equations for gain and synthesis error are nonlinear equations which normally cannot be solved analytically. Therefore, numerical techniques (optimization algorithms) are used to find reactive loads for both maximum gain in a specified direction and a synthesized pattern.

Download or read book Phased Array Antennas with Optimized Element Patterns written by Sergei P. Skobelev and published by Artech House. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative resource provides you with a detailed description of ideal array element characteristics that help you estimate the quality of development of real-world phased array antennas. You find several approaches to optimum phased array design, allowing you to provide specified array gain in a specific region of scan, using a minimum number of expensive, controlled devices. Moreover, this practical book presents important numerical methods that you can use to model and optimize phased array structure to obtain the best array characteristics that the chosen structure can provide.From arrays with beam-forming networks, arrays of coupled dual-mode waveguides, and arrays with reactively loaded radiators, to waveguide arrays with protruding dielectric elements, and arrays with strip, disk, and wire structures, this comprehensive reference explains a wide range of essential topics to help you with work in this challenging area. The book is supported with over 165 illustrations and more than 566 equations.

Download or read book Fractal Apertures in Waveguides Conducting Screens and Cavities written by Basudeb Ghosh and published by Springer. This book was released on 2014-06-12 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the design and analysis of fractal apertures in waveguides, conducting screens and cavities using numerical electromagnetics and field-solvers. The aim is to obtain design solutions with improved accuracy for a wide range of applications. To achieve this goal, a few diverse problems are considered. The book is organized with adequate space dedicated for the design and analysis of fractal apertures in waveguides, conducting screens and cavities, microwave/millimeter wave applications followed by detailed case-study problems to infuse better insight and understanding of the subject. Finally, summaries and suggestions are given for future work. Fractal geometries were widely used in electromagnetics, specifically for antennas and frequency selective surfaces (FSS). The self-similarity of fractal geometry gives rise to a multiband response, whereas the space-filling nature of the fractal geometries makes it an efficient element in antenna and FSS unit cell miniaturization. Until now, no efforts were made to study the behavior of these fractal geometries for aperture coupling problems. The aperture coupling problem is an important boundary value problem in electromagnetics and used in waveguide filters and power dividers, slotted ground planes, frequency selective surfaces and metamaterials. The present book is intended to initiate a study of the characteristics of fractal apertures in waveguides, conducting screens and cavities. To perform a unified analysis of these entirely dissimilar problems, the “generalized network formulation of the aperture problems” by Mautz and Harrington was extended to multiple-aperture geometry. The authors consider the problem of coupling between two arbitrary regions coupled together via multiple apertures of arbitrary shape. MATLAB codes were developed for the problems and validated with the results available in the literature as well as through simulations on ANSOFT's HFSS.

Download or read book Fundamentals of Aperture Antennas and Arrays written by Trevor S. Bird and published by John Wiley & Sons. This book was released on 2016-01-19 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended as an advanced text for courses in antennas, with a focus on the mature but vital background field of aperture antennas. The book is aimed at final year, MSc, PhD and Post-Doctoral students, as well as readers who are moving from academia into industry, beginning careers as wireless engineers, system designers, in R&D, or for practising engineers. It assumes the reader has undertaken an earlier course of study on Maxwell's equations, fields and waves. Some of these topics are summarised in the early few chapters in order to provide continuity and background for the remaining chapters. The aperture antennas covered include the main types of horns, reflectors and arrays as well as microstrip patches, reflectarrays and lenses. To provide more than a superficial treatment of arrays, the topic of mutual coupling is covered in greater detail than most similar books in the area. Also included is an introduction to arrays on non-planar surfaces, which is of importance for applications that involve curved surfaces such as in aerodynamics or for making aperture antennas unobtrusive. A chapter is included on some modern aperture antennas to illustrate design techniques beyond the most common types of aperture antennas described in the early chapters. This is to show where advances have recently been made and where they could be improved in the future. Also included are selected topics of a practical nature for aperture antennas, namely fabrication and measurement.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parasitic Antenna Arrays for Wireless MIMO Systems written by Antonis Kalis and published by Springer Science & Business Media. This book was released on 2013-10-11 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Ultrawideband Phased Array Antenna Technology for Sensing and Communications Systems written by Alan J. Fenn and published by MIT Press. This book was released on 2015-04-10 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical ultrawideband phased array technology used in airborne and ground-based systems applications. Ultrawideband phased array antennas are an enabling technology for many ground-based and airborne communications and radar systems. This book surveys electromagnetic theory and phased array antenna theory and provides examples of ultrawideband phased array antenna technology. It describes some of the research on ultrawideband phased arrays undertaken by the authors and their colleagues at MIT Lincoln Laboratory over the last ten years. The book focuses on experimental prototype ultrawideband phased array technology developed at Lincoln Laboratory for applications in the VHF and UHF bands from approximately 100 MHz to 1 GHz, and addresses dipole, monopole, loop, and other antenna array elements. It offers examples of antennas for both airborne and ground vehicle applications. Most of the examples are developed in the context of rapid prototyping for quick assessment of communications and radar systems feasibility, with measurements and numerical electromagnetic simulation results provided for many prototype examples. The book is intended primarily for practicing antenna engineers, radar engineers, and communications engineers, and for graduate students and researchers in electrical engineering. Readers need no prior knowledge of ultrawideband antennas, although some background in electromagnetic theory, antennas, radar, and communications would be helpful.

Download or read book Characteristic Modes written by Yikai Chen and published by John Wiley & Sons. This book was released on 2015-05-19 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes how to systematically implement various characteristic mode (CM) theories into designs of practical antenna systems This book examines both theoretical developments of characteristic modes (CMs) and practical developments of CM-based methodologies for a variety of critical antenna designs. The book is divided into six chapters. Chapter 1 provides an introduction and discusses the recent advances of the CM theory and its applications in antenna engineering. Chapter 2 describes the formulation of the characteristic mode theory for perfectly electrically conducting (PEC) bodies and discusses its numerical implementations. Chapter 3 presents the CM theory for PEC structures embedded in multilayered medium and its applications. Chapter 4 covers recent advances in CM theory for dielectric bodies and also their applications. Chapter 5 discusses the CM theory for N-port networks and its applications to the design of antenna arrays. Finally, Chapter 6 discusses the design of platform-integrated antenna systems using characteristic modes. This book features the following: Introduces characteristic mode theories for various electromagnetic structures including PEC bodies, structures in multilayered medium, dielectric bodies, and N-port networks Examines CM applications in electrically small antennas, microstrip patch antennas, dielectric resonator antennas, multiport antennas, antenna arrays, and platform mounted antenna systems Discusses numerical algorithms for the implementation of the characteristic mode theories in computer code Characteristic Modes: Theory and Applications in Antenna Engineering will help antenna researchers, engineers, and students find new solutions for their antenna design challenges.

Download or read book Modern Antenna Handbook written by Constantine A. Balanis and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 1617 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most up-to-date, comprehensive treatment of classical and modern antennas and their related technologies Modern Antenna Handbook represents the most current and complete thinking in the field of antennas. The handbook is edited by one of the most recognizable, prominent, and prolific authors, educators, and researchers on antennas and electromagnetics. Each chapter is authored by one or more leading international experts and includes cover-age of current and future antenna-related technology. The information is of a practical nature and is intended to be useful for researchers as well as practicing engineers. From the fundamental parameters of antennas to antennas for mobile wireless communications and medical applications, Modern Antenna Handbook covers everything professional engineers, consultants, researchers, and students need to know about the recent developments and the future direction of this fast-paced field. In addition to antenna topics, the handbook also covers modern technologies such as metamaterials, microelectromechanical systems (MEMS), frequency selective surfaces (FSS), and radar cross sections (RCS) and their applications to antennas, while five chapters are devoted to advanced numerical/computational methods targeted primarily for the analysis and design of antennas.

Download or read book Reconfigurable Antennas written by Jennifer T. Bernhard and published by Springer Nature. This book was released on 2022-05-31 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: This lecture explores the emerging area of reconfigurable antennas from basic concepts that provide insight into fundamental design approaches to advanced techniques and examples that offer important new capabilities for next-generation applications. Antennas are necessary and critical components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Making antennas reconfigurable so that their behavior can adapt with changing system requirements or environmental conditions can ameliorate or eliminate these restrictions and provide additional levels of functionality for any system. For example, reconfigurable antennas on portable wireless devices can help to improve a noisy connection or redirect transmitted power to conserve battery life. In large phased arrays, reconfigurable antennas could be used to provide additional capabilities that may result in wider instantaneous frequency bandwidths, more extensive scan volumes, and radiation patterns with more desirable side lobe distributions. Written for individuals with a range of experience, from those with only limited prior knowledge of antennas to those working in the field today, this lecture provides both theoretical foundations and practical considerations for those who want to learn more about this exciting subject. Contents: Introduction / Definitions of Critical Parameters for Antenna Operation / Linkage Between Frequency Response and Radiation Characteristics: Implications for Reconfigurable Antennas / Methods for Achieving Frequency Response Reconfigurability / Methods for Achieving Polarization Reconfigurability / Methods for Achieving Radiation Pattern Reconfigurability / Methods for Achieving Compound Reconfigurable Antennas / Practical Issues for Implementing Reconfigurable Antennas / Conclusions and Directions for Future work

Download or read book Switched Parasitic Antennas for Cellular Communications written by David V. Thiel and published by Artech House. This book was released on 2002 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Presenting information typically not found in other books, the authors explore the numerous advantages of these antennas - including high-speed signal acquisition, fixed input impedance, low loss, and small footprint. Professionals find practical design examples, strategies, and optimization methods for designing economical switched parasitic antennas for applications such as direction finding and multibeam communications systems. Cutting-edge technologies and applications such as MEMs RF switches are also discussed."--Jacket.

Download or read book Array and Phased Array Antenna Basics written by Hubregt J. Visser and published by John Wiley & Sons. This book was released on 2006-02-03 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting a growing interest in phased array antenna systems, stemming from radar, radio astronomy, mobile communications and satellite broadcasting, Array and Phased Array Antenna Basics introduces the principles of array and phased array antennas. Packed with first-hand practical experience and worked-out examples, this is a valuable learning tool and reference source for those wishing to improve their understanding of basic array antenna systems without relying heavily on a thorough knowledge of electromagnetics or antenna theory. Features a general introduction to antennas and explains the array antenna principle through discussion of the physical characteristics rather than the theory Explores topics often not covered in antenna textbooks, such as active element pattern, array feeding, means of phase changing, array antenna characterisation, sequential rotation techniques and reactively loaded arrays Guides the reader through the necessary mathematics, allowing them to move onto specialist books on array and phased array antennas with a greater understanding of the topic Supported by a companion website on which instructors and lecturers can find electronic versions of the figures An ideal introduction for those without a background in antennas, this clear, concise volume will appeal to technicians, researchers and managers working in academia, government, telecommunications and radio astronomy. It will also be a valuable resource for professionals and postgraduates with some antenna knowledge.

Download or read book Pattern Magnitude Synthesis for a Reactively Loaded Circular Antenna Array written by John Luzwick and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a method for synthesizing a given radiation field magnitude pattern for a reactively loaded circular dipolar array. The reactively loaded circular dipole array has the center dipole fed and the outer dipoles parasitically excited with reactive loads across their input terminals. Both seven and thirteen element arrays are considered. A Rosenbrock optimization algorithm is applied directly to the synthesis error function to determine the reactive loads required for minimum error. Any arbitrarily shaped magnitude pattern can be treated. The pattern magnitude synthesis results for the reactively loaded array are compared to that of an optimally excited array. A computer program for the optimization algorithm with operating instructions is included. (Author).

Download or read book Phased Arrays for Radio Astronomy Remote Sensing and Satellite Communications written by Karl F. Warnick and published by Cambridge University Press. This book was released on 2018-07-26 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover a modern approach to the analysis, modeling and design of high sensitivity phased arrays. Network theory, numerical methods and computational electromagnetic simulation techniques are uniquely combined to enable full system analysis and design optimization. Beamforming and array signal processing theory are integrated into the treatment from the start. Digital signal processing methods such as polyphase filtering and RFI mitigation are described, along with technologies for real-time hardware implementation. Key concepts from interferometric imaging used in radio telescopes are also considered. A basic development of theory and modeling techniques is accompanied by problem sets that guide readers in developing modeling codes that retain the simplicity of the classical array factor method while incorporating mutual coupling effects and interactions between elements. Combining current research trends with pedagogical material suitable for a first-year graduate course, this is an invaluable resource for students, teachers, researchers, and practicing RF/microwave and antenna design engineers.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1990 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: