Download or read book Near field Phase Transformation for Radiation Performance Enhancement and Beam Steering of Resonant Cavity Antennas written by Muhammad Usman Afzal and published by . This book was released on 2016 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonant-cavity antennas (RCAs) are promising candidates in advanced wireless applications because of their moderate-to-high gain, simple configuration, low and planar profile, and lack of feed networks. This dissertation presents novel mechanisms to enhance directivity and other radiation characteristics and to steer beam of RCAs. Solutions to both challenges are based on near-field phase transformation and have been demonstrated by designing metasurfaces for this transformation. A classical RCA comprising of a patch antenna and an unprinted all-dielectric superstructure is considered as the base antenna to assess the effectiveness of the proposed solutions. To enhance directive radiation characteristics, a near-field phase transformation methodology is developed to improve the uniformity of electric near-field phase distribution. This is realized by designing several phase-correcting structures/ surfaces (PCSs). This novel method employs electromagnetic (EM) simulators to accurately obtain a non-uniform phase distribution on the aperture of RCAs. Two different types of PCSs prototypes were developed. The first proof-of-concept prototype is an all-dielectric varying-height PCS with a stepped geometry, which corrects the phase at discrete points on the RCA aperture. Simulation and measurement results of the classical RCA with the PCS indicate that the PCS increases the peak directivity of the RCA by 9 dB (from 12.5 dBi to 21.2 dBi) and enhances its uniform aperture area by 178%. As an extension to this, a quasi-analytical approach is developed and is utilised to synthesise a continuous PCS for a circularly polarized ( CP) RCA. The performance of the continuous PCS is evaluated through numerical simulations, and predicted results indicate that the improvement in radiation performance is comparable to what was achieved with the former dielectric PCS. The second PCS prototype was a compact, lightweight design, which was implemented using printed phase-shifting elements. The planar PCS prototype is 57% lighter and is only 9% of the maximum height of the all-dielectric PCS prototype. The RCA with the planar PCS has the peak directivity of 20.5 dBi, which is 8 dB higher than that of without PCS. To address beam steering, a mechanism based on the rotation of a sawtooth time-delay (STD) metasurface pair is presented. The metasurface pair is physically located on the aperture of the RCA, in the near-field region for the purpose of phase transformation. Each metasurface was designed to create a STD in the propagating electric field so that the beam is tilted by an angle of 20°. The metasurface pair is rotated concurrently and independently, to move the beam to any direction in a conical region with a 92° vertex angle. As a technical demonstration, only a few angular positions were tested, however, the system is capable of scanning the whole angular space. The peak realized gain of 19.4 dBi was achieved in the broadside direction and the gain was 17.5 dBi when the beam was moved to the farthest elevation angle of 46°. The conspicuous attributes of the proposed beam-steering system are its extremely low-profile, which is 34.6 mm or 1.3;.\0, its passive nature, and its ability to maintain planar geometry during scanning. The proposed solution of near-field phase transformation successfully demonstrates radiation performance enhancements and beam steering of RCAs. Although the methodology was demonstrate for RCAs, this approach is applicable to other planar antennas and arrays.

Download or read book RF Antenna Beam Forming written by Shun-Ping Chen and published by Springer Nature. This book was released on 2023-03-24 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is designed for both the scientific audience, research and development engineers and the university students. The fundamentals of radio frequency antenna beam forming is explained in this book. The principles of beam focusing and beam steering in near field and far field are visualized with 2D and 3D simulations and compared with measurement results. Besides linear and planar antenna arrays, also conformal arrays, i.e. concave and convex antenna arrays, suitable for certain applications, are investigated and presented. Also related applications of radio frequency beam forming like open loop and closed loop large scale antenna arrays or massive MIMO, which is one of the break-through technologies for 5G and future 6G and involves an extremely large number of antenna elements for the multi-user beam forming, as well as thinned antenna arrays with electrically large distances between the antenna elements are discussed.

Download or read book Aperture Antennas for Millimeter and Sub Millimeter Wave Applications written by Artem Boriskin and published by Springer. This book was released on 2017-09-05 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the technology of millimetre waves and Terahertz (THz) antennas. It highlights the importance of moderate and high-gain aperture antennas as key devices for establishing point-to-point and point-to-multipoint radio links for far-field and near-field applications, such as high data-rate communications, intelligent transport, security imaging, exploration and surveillance systems. The book provides a comprehensive overview of the key antenna technologies developed for the mm wave and THz domains, including established ones – such as integrated lens antennas, advanced 2D and 3D horn antennas, transmit and reflect arrays, and Fabry-Perot antennas – as well as emerging metasurface antennas for near-field and far-field applications. It describes the pros and cons of each antenna technology in comparison with other available solutions, a discussion supplemented by practical examples illustrating the step-by-step implementation procedures for each antenna type. The measurement techniques available at these frequency ranges are also presented to close the loop of the antenna development cycle. In closing, the book outlines future trends in various antenna technologies, paving the way for further developments. Presenting content originating from the five-year ESF research networking program ‘Newfocus’ and co-authored by the most active and highly cited research groups in the domain of mm- and sub-mm-wave antenna technologies, the book offers a valuable guide for researchers and engineers in both industry and academia.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 2019 International Conference on Electromagnetics in Advanced Applications ICEAA written by IEEE Staff and published by . This book was released on 2019-09-09 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The 21th edition of the ICEAA is coupled to the 9th edition of the IEEE APWC The two conferences consist of invited and contributed papers, and share a common organization, registration fee, submission site, workshops and short courses, and social events The proceedings of both conferences will be published on IEEE Xplore

Download or read book Microstrip Patch Antennas A Designer s Guide written by Rod Waterhouse and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This useful tool provides the reader with a current overview of where microstrip patch antenna technology is at, and useful information on how to design this form of radiator for their given application and scenario. Practical design cases are provided for each goal.

Download or read book Conformal Array Antenna Theory and Design written by Lars Josefsson and published by John Wiley & Sons. This book was released on 2006-02-10 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first comprehensive treatment of conformal antenna arrays from an engineering perspective. While providing a thorough foundation in theory, the authors of this publication provide a wealth of hands-on instruction for practical analysis and design of conformal antenna arrays. Thus, you get the knowledge you need, alongside the practical know-how to design antennas that are integrated into such structures aircrafts or skyscrapers.

Download or read book Reflectarray Antennas written by Payam Nayeri and published by John Wiley & Sons. This book was released on 2018-02-23 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides engineers with a comprehensive review of the state-of-the-art in reflectarray antenna research and development. The authors describe, in detail, design procedures for a wide range of applications, including broadband, multi-band, multi-beam, contour-beam, beam-scanning, and conformal reflectarray antennas. They provide sufficient coverage of basic reflectarray theory to fully understand reflectarray antenna design and analysis such that the readers can pursue reflectarray research on their own. Throughout the book numerous illustrative design examples including numerical and experimental results are provided. Featuring in-depth theoretical analysis along with practical design examples, em style="mso-bidi-font-style: normal;"Reflectarray Antennas is an excellent text/reference for engineering graduate students, researchers, and engineers in the field of antennas. It belongs on the bookshelves of university libraries, research institutes, and industrial labs and research facilities.

Download or read book Antennas written by Yi Huang and published by John Wiley & Sons. This book was released on 2008-09-15 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical, concise and complete reference for the basics of modern antenna design Antennas: from Theory to Practice discusses the basics of modern antenna design and theory. Developed specifically for engineers and designers who work with radio communications, radar and RF engineering, this book offers practical and hands-on treatment of antenna theory and techniques, and provides its readers the skills to analyse, design and measure various antennas. Key features: Provides thorough coverage on the basics of transmission lines, radio waves and propagation, and antenna analysis and design Discusses industrial standard design software tools, and antenna measurement equipment, facilities and techniques Covers electrically small antennas, mobile antennas, UWB antennas and new materials for antennas Also discusses reconfigurable antennas, RFID antennas, Wide-band and multi-band antennas, radar antennas, and MIMO antennas Design examples of various antennas are provided Written in a practical and concise manner by authors who are experts in antenna design, with experience from both academia and industry This book will be an invaluable resource for engineers and designers working in RF engineering, radar and radio communications, seeking a comprehensive and practical introduction to the basics of antenna design. The book can also be used as a textbook for advanced students entering a profession in this field.

Download or read book Spaceborne Antennas for Planetary Exploration written by William A. Imbriale and published by John Wiley & Sons. This book was released on 2006-08-04 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: JPL spacecraft antennas-from the first Explorer satellite in 1958 to current R & D Spaceborne Antennas for Planetary Exploration covers the development of Jet Propulsion Laboratory (JPL) spacecraft antennas, beginning with the first Explorer satellite in 1958 through current research and development activities aimed at future missions. Readers follow the evolution of all the new designs and technological innovations that were developed to meet the growing demands of deep space exploration. The book focuses on the radio frequency design and performance of antennas, but covers environmental and mechanical considerations as well. There is additionally a thorough treatment of all the analytical and measurement techniques used in design and performance assessment. Each chapter is written by one or more leading experts in the field of antenna technology. The presentation of the history and technology of spaceborne antennas is aided by several features: * Photographs and drawings of JPL spacecraft * Illustrations to help readers visualize concepts and designs * Tables highlighting and comparing the performance of the antennas * Bibliographies at the end of each chapter leading to a variety of primary and secondary source material This book complements Large Antennas of the Deep Space Network (Wiley 2002), which surveys the ground antennas covered in support of spacecraft. Together, these two books completely cover all JPL antenna technology, in keeping with the JPL Deep Space Communications and Navigation Series mission to capture and present the many innovations in deep space telecommunications over the past decades. This book is a fascinating and informative read for all individuals working in or interested in deep space telecommunications.

Download or read book Microstrip Patch Antennas written by Kai Fong Lee and published by World Scientific. This book was released on 2011 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstrip patch antennas have become the favorite of antenna designers because of its versatility and advantages of planar profile, ease of fabrication, compatibility with integrated circuit technology, and conformability with a shaped surface. As there is currently an urgent need for graduate students and practicing engineers to gain an in-depth understanding of this subject, this book was written with this purpose in mind. The authors are IEEE Fellows who have made significant contributions to their fields of expertise. Professor K F Lee was the recipient of the 2009 John Kraus Antenna Award of the IEEE Antennas and Propagation Society.

Download or read book Nonlinear Meta Optics written by Costantino De Angelis and published by CRC Press. This book was released on 2020-05-20 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses fabrication as well as characterization and modeling of semiconductor nanostructures in the optical regime, with a focus on nonlinear effects. The visible range as well as near and far infrared spectral region will be considered with a view to different envisaged applications. The book covers the current key challenges of the research in the area, including: exploiting new material platforms, fully extending the device operation into the nonlinear regime, adding re-configurability to the envisaged devices and proposing new modeling tools to help in conceiving new functionalities. • Explores several topics in the field of semiconductor nonlinear nanophotonics, including fabrication, characterization and modeling of semiconductor nanostructures in the optical regime, with a focus on nonlinear effects • Describes the research challenges in the field of optical metasurfaces in the nonlinear regime • Reviews the use and achievements of all-dielectric nanoantennas for strengthening the nonlinear optical response • Describes both theoretical and experimental aspects of photonic devices based on semiconductor optical nanoantennas and metasurfaces • Gathers contributions from several leading groups in this research field to provide a thorough and complete overview of the current state of the art in the field of semiconductor nonlinear nanophotonics Costantino De Angelis has been full professor of electromagnetic fields at the University of Brescia since 1998. He is an OSA Fellow and has been responsible for several university research contracts in the last 20 years within Europe, the United States, and Italy. His technical interests are in optical antennas and nanophotonics. He is the author of over 150 peer-reviewed scientific journal articles. Giuseppe Leo has been a full professor in physics at Paris Diderot University since 2004, and in charge of the nonlinear devices group of MPQ Laboratory since 2006. His research areas include nonlinear optics, micro- and nano-photonics, and optoelectronics, with a focus on AlGaAs platform. He has coordinated several research programs and coauthored 100 peer-reviewed journal articles, 200 conference papers, 10 book chapters and also has four patents. Dragomir Neshev is a professor in physics and the leader of the experimental photonics group in the Nonlinear Physics Centre at Australian National University (ANU). His activities span over several branches of optics, including nonlinear periodic structures, singular optics, plasmonics, and photonic metamaterials. He has coauthored 200 publications in international peer-reviewed scientific journals.

Download or read book Microstrip and Printed Antennas written by Debatosh Guha and published by John Wiley & Sons. This book was released on 2011-02-02 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on new techniques, analysis, applications and future trends of microstrip and printed antenna technologies, with particular emphasis to recent advances from the last decade Attention is given to fundamental concepts and techniques, their practical applications and the future scope of developments. Several topics, essayed as individual chapters include reconfigurable antenna, ultra-wideband (UWB) antenna, reflectarrays, antennas for RFID systems and also those for body area networks. Also included are antennas using metamaterials and defected ground structures (DGSs). Essential aspects including advanced design, analysis and optimization techniques based on the recent developments have also been addressed. Key Features: Addresses emerging hot topics of research and applications in microstrip and printed antennas Considers the fundamental concepts, techniques, applications and future scope of such technologies Discusses modern applications such as wireless base station to mobile handset, satellite earth station to airborne communication systems, radio frequency identification (RFID) to body area networks, etc. Contributions from highly regarded experts and pioneers from the US, Europe and Asia This book provides a reference for R&D researchers, professors, practicing engineers, and scientists working in these fields. Graduate students studying/working on related subjects will find this book as a comprehensive literature for understanding the present and future trends in microstrip and printed antennas.

Download or read book Information Metamaterials written by Tie Jun Cui and published by Cambridge University Press. This book was released on 2021-02-18 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metamaterials have attracted enormous interests from both physics and engineering communities in the past 20 years, owing to their powerful ability in manipulating electromagnetic waves. However, the functionalities of traditional metamaterials are fixed at the time of fabrication. To control the EM waves dynamically, active components are introduced to the meta-atoms, yielding active metamaterials. Recently, a special kind of active metamaterials, digital coding and programmable metamaterials, are proposed, which can achieve dynamically controllable functionalities using field programmable gate array (FPGA). Most importantly, the digital coding representations of metamaterials set up a bridge between the digital world and physical world, and allow metamaterials to process digital information directly, leading to information metamaterials. In this Element, we review the evolution of information metamaterials, mainly focusing on their basic concepts, design principles, fabrication techniques, experimental measurement and potential applications. Future developments of information metamaterials are also envisioned.

Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1334 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 1974 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.