Download or read book Active Frequency Selective Surfaces for Antenna Applications Electronically to Control Phase Distribution and Reflective Transmissive Amplification written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A planar dipole grid antenna is described deposited on an active frequency selective (FSS) or polarization sensitive surface (PSS) electronically tuneable to control the spatial phase distribution and reflective/transmissive amplification. Such dipole grids can be used, for example, in reflector antenna systems composed of multiple reflective and/or transmissive subsystems to achieve and serve highly cost-effective multi-purpose applications. It is discussed how the resonant frequency or/and the type of polarization can be tuned just by varying the steering voltage or current of electronically tunable components such as varactor diodes or YIG films, respectively, implemented and integrated with each of the radiating dipole elements. The theoretical analysis for this paper is based upon a specific Floquet theory approach for single/double/triple periodic antenna structures. The resulting system of coupled vector integral equations for the unknown electric and magnetic current distribution is numerically solved by applying the method of moments supported by Galerkin s process of weighting. The experimental investigations were performed by developing a waveguide simulation technique in the frequency range of 7 to 16 GHz. Results of selected measurements are presented for quantities such as: the spatially dependent reflection/transmission coefficients (magnitude, phase) as a function of signal frequency; the intrinsic input impedance / matching of the various dipole elements involved, etc.; and in addition to that - the resulting electronically achievable phase advance/delay and amplification of the active antenna system as well. A one/two-dimensional enlarged planar dipole grid of about 40 mm x 25 mm in aperture size was deposited inside an adequately tapered waveguide to reduce tolerance problems and to suppress higher order modes.

Download or read book Handbook of Metamaterial Derived Frequency Selective Surfaces written by Shiv Narayan and published by Springer Nature. This book was released on 2023-01-02 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a consolidated reference for the applications of frequency selective surfaces (FSS) technology in different sectors such as wireless communications, smart buildings, microwave and medical industries. It covers all aspects of metamaterial FSS technology starting from theoretical simulation, fabrication and measurement all the way to actual hardware implementation. Also included are in-depth discussions on the design methodologies of metamaterial FSS structures and their practical implementation in devices and components. It will be of interest to researchers and engineers working on developing metamaterial-FSS technology.

Download or read book Newsletter written by and published by . This book was released on 2004 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1961-05 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.

Download or read book Spectrally Selective Surfaces for Heating and Cooling Applications written by Claes G. Granqvist and published by SPIE Press. This book was released on 1989 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Tutorial Text covers coatings and surface treatments for energy-efficient windows of many different kinds, for solar collectors, and for radiative coolers. The desired spectral properties of these surfaces are introduced through a discussion of the radiation that prevails in our natural ambience. Emphasized are materials options, coating techniques, experimental data on optical properties, theoretical models for pertinent materials, and optimization studies with regard to practical applications. The book should be of interest to people working R&D in industry, universities, and national and international institutions who are engaged in issues related to energy efficiency and solar energy utilization.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multi Band Frequency Selective Surfaces Analysis written by and published by . This book was released on 2008 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Present trends in antenna development go toward the integration on the same antenna aperture of more functions operating in separate frequency bands. In view of this, the necessity to look at new Frequency Selective Surface (FSS) concepts becomes evident. These structures should have pass-bands corresponding to the antenna operational frequencies sandwiched between sharp stop-bands. An advanced tool has been developed at TNO for the analysis and design of multi-layer FSSs. In the frame of Phase I of the Multiband Frequency Selective Surface project defined within the ITM programme, the tool has been upgraded with new features that allow handling new complex geometries. The tool has been equipped with a triangular mesh and the electric and magnetic currents on the FSS elements have been discretised in terms of Rao Wilton Olisson functions. Moreover, the application of the bitmapping design technique requires considering completely metallised unit cells and therefore ensuring the continuity of the currents across adjacent cells. A further upgrade in this direction has been introduced in the tool. The new implementations have been tested against results available in the open literature and the obtained agreement is very good.

Download or read book Application of Frequency Selective Surfaces in Circular Polarization Antenna Technologies written by Robert Mervyn Orr and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Design of Transmitarray Antennas written by Ahmed H. Abdelrahman and published by Morgan & Claypool Publishers. This book was released on 2017-01-18 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, transmitarray antennas have attracted growing interest with many antenna researchers. Transmitarrays combines both optical and antenna array theory, leading to a low profile design with high gain, high radiation efficiency, and versatile radiation performance for many wireless communication systems. In this book, comprehensive analysis, new methodologies, and novel designs of transmitarray antennas are presented. Detailed analysis for the design of planar space-fed array antennas is presented. The basics of aperture field distribution and the analysis of the array elements are described. The radiation performances (directivity and gain) are discussed using array theory approach, and the impacts of element phase errors are demonstrated. The performance of transmitarray design using multilayer frequency selective surfaces (M-FSS) approach is carefully studied, and the transmission phase limit which are generally independent from the selection of a specific element shape is revealed. The maximum transmission phase range is determined based on the number of layers, substrate permittivity, and the separations between layers. In order to reduce the transmitarray design complexity and cost, three different methods have been investigated. As a result, one design is performed using quad-layer cross-slot elements with no dielectric material and another using triple-layer spiral dipole elements. Both designs were fabricated and tested at X-Band for deep space communications. Furthermore, the radiation pattern characteristics were studied under different feed polarization conditions and oblique angles of incident field from the feed. New design methodologies are proposed to improve the bandwidth of transmitarray antennas through the control of the transmission phase range of the elements. These design techniques are validated through the fabrication and testing of two quad-layer transmitarray antennas at Ku-band. A single-feed quad-beam transmitarray antenna with 50 degrees elevation separation between the beams is investigated, designed, fabricated, and tested at Ku-band. In summary, various challenges in the analysis and design of transmitarray antennas are addressed in this book. New methodologies to improve the bandwidth of transmitarray antennas have been demonstrated. Several prototypes have been fabricated and tested, demonstrating the desirable features and potential new applications of transmitarray antennas.

Download or read book Frequency Selective Surfaces written by Luisa Deias and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1967 with total page 1206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling and Design of Frequency Selective Surfaces for Reflector Antennas written by C. K. Lee and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Selective Surface and Grid Array written by T. K. Wu and published by Wiley-Interscience. This book was released on 1995-07-31 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new addition to the prestigious Wiley Series in Microwave and Optical Engineering presents the first comprehensive coverage of Frequency Selective Surfaces (FSS) and active grid arrays, the two-dimensional periodically arranged array elements which may be etched on, or imbedded in, one or multiple layers of dielectric laminates. Because of its filtering frequency properties, this technology, which has attracted much interest over the past two decades, is being used to create filtering devices in microwave and higher frequency bands. With Frequency Selective Surface and Grid Array, it is no longer necessary to sift through a multitude of research papers and reports. Here, in one self-contained volume, is a thorough and up-to-date treatment of the concept, theory, applications, design, and fabrication techniques for periodic arrays. Furthermore, the book provides a complete reference for the technological advances in FSS, including the recent technology of active grid arrays. The first part of the book is devoted to the fundamentals and analytical techniques pertaining to FSS and grid arrays, including the advanced analyses of the conjugate gradient method and the generalized mode-matching technique with multiple dielectrics or nonsimilar grid arrays. In the second part, the book deals with implementation and application, describing the numerous applications of this technology, from the reflector antenna system used in satellite and spacecraft communications and bandpass radome to solar energy grids. The expert contributions to this volume make it useful both as a tutorial and as a reference for project and system/design engineers working with antennas, optics, millimeter waves, microwaves, radar, and low observable radomes. A comprehensive and self-contained reference for FSS and grid array technology Frequency Selective Surfaces (FSS), the two-dimensional periodic array elements with frequency filtering properties, have made important advances over the past two decades. They provide filtering devices in microwave and higher frequency bands with applications ranging from bandpass radome to solar energy grids—including satellite and spacecraft communications. Written by experts in the field and edited by Dr. T. K. Wu, an internationally recognized researcher in electromagnetics, Frequency Selective Surface and Grid Array provides the first comprehensive look at the theory, measurements, manufacturing, and applications of FSS and grid array technology. This publication brings together a wealth of information previously not available in book form, as well as material that has not been published anywhere, including: Passive and active grid design concepts and analysis, as well as FSS materials and fabrication techniques Practical design of frequency selective surface, high-performance bandpass radome, and active grid array Detailed equations for the reaction integrals Three computer codes to get readers started in the design of FSS and grid array (disk included) Case studies of FSS applications to multiband communication antenna systems Tables, figures, references, and numerous examples of practical FSS and grid array designs A tutorial analysis that includes the multilayer grid and dielectrics Frequency Selective Surface and Grid Array is an invaluable planning and design resource for research engineers and scientists dealing with FSS and grid array, as well as a handy reference for students and professionals entering the field.

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1972 with total page 1248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Selective Surfaces written by Ben A. Munk and published by John Wiley & Sons. This book was released on 2005-03-11 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: "...Ben has been the world-wide guru of this technology, providing support to applications of all types. His genius lies in handling the extremely complex mathematics, while at the same time seeing the practical matters involved in applying the results. As this book clearly shows, Ben is able to relate to novices interested in using frequency selective surfaces and to explain technical details in an understandable way, liberally spiced with his special brand of humor... Ben Munk has written a book that represents the epitome of practical understanding of Frequency Selective Surfaces. He deserves all honors that might befall him for this achievement." -William F. Bahret. Mr. W. Bahret was with the United States Air Force but is now retired. From the early 50s he sponsored numerous projects concerning Radar Cross Section of airborne platforms in particular antennas and absorbers. Under his leadership grew many of the concepts used extensively today, as for example the metallic radome. In fact, he is by many considered to be the father of stealth technology. "This book compiles under one cover most of Munk's research over the past three decades. It is woven with the physical insight that he has gained and further developed as his career has grown. Ben uses mathematics to whatever extent is needed, and only as needed. This material is written so that it should be useful to engineers with a background in electromagnetics. I strongly recommend this book to any engineer with any interest in phased arrays and/or frequency selective surfaces. The physical insight that may be gained from this book will enhance their ability to treat additional array problems of their own." -Leon Peters, Jr. Professor Leon Peters, Jr., was a professor at the Ohio State University but is now retired. From the early sixties he worked on, among many other things, RCS problems involving antennas and absorbers. This book presents the complete derivation of the Periodic Method of Moments, which enables the reader to calculate quickly and efficiently the transmission and reflection properties of multi-layered Frequency Selective Surfaces comprised of either wire and/or slot elements of arbitrary shape and located in a stratified medium. However, it also gives the reader the tools to analyze multi-layered FSS's leading to specific designs of the very important Hybrid Radome, which is characterized by constant band width with angle of incidence and polarization. Further, it investigates in great detail bandstop filters with large as well as narrow bandwidth (dichroic surfaces). It also discusses for the first time, lossy elements used in producing Circuit Analog absorbers. Finally, the last chapter deals with power breakdown of FSS's when exposed to pulsed signals with high peak power. The approach followed by most other presentations simply consists of expanding the fields around the FSS, matching the boundary conditions and writing a computer program. While this enables the user to obtain calculated results, it gives very little physical insight and no help in how to design actual multi-layered FSS's. In contrast, the approach used in this title analyzes all curves of desired shapes. In particular, it discusses in great detail how to produce radomes made of FSS's located in a stratified medium (Hybrid Radomes), with constant band width for all angles of incidence and polarizations. Numerous examples are given of great practical interest. More specifically, Chapter 7 deals with the theory and design of bandpass radomes with constant bandwidth and flat tops. Examples are given for mono-, bi- and tri-planar designs. Chapter 8 deals with bandstop filters with broad as well as narrow bandwidth. Chapter 9 deals with multi-layered FSS of lossy elements, namely the so-called Circuit Analog Absorbers, designed to yield outstanding absorption with more than a decade of bandwidth. Features material previously labeled as classified by the United States Air Force.

Download or read book Distributed Power Amplifiers for RF and Microwave Communications written by Narendra Kumar and published by Artech House. This book was released on 2015-06-01 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new resource presents readers with all relevant information and comprehensive design methodology of wideband amplifiers. This book specifically focuses on distributed amplifiers and their main components, and presents numerous RF and microwave applications including well-known historical and recent architectures, theoretical approaches, circuit simulation, and practical implementation techniques. A great resource for practicing designers and engineers, this book contains numerous well-known and novel practical circuits, architectures, and theoretical approaches with detailed description of their operational principles.

Download or read book Proceedings of the IRE written by Institute of Radio Engineers and published by . This book was released on 1962 with total page 1206 pages. Available in PDF, EPUB and Kindle. Book excerpt: