Download or read book Fresnel Zones for Ground Based Antennas written by J. Bach Andersen and published by . This book was released on 1963 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ordinary Fresnel zone concept is extended to include the influence of finite con ductivity. This is important for ground-based antennas because the influence on the radiation pattern of irregularities near the antenna is determined by the amplitude and phase of the groundwave. Only discontinuities of the elec trical parameters of the ground are considered. Extensive numerical results for the first Fresnel zone are given, and it is shown that the zone is much smaller for a finite conductivity than for an infinite conductivity, especially for small angles of elevation. (Author).
Download or read book Basic Principles of Fresnel Antenna Arrays written by Igor V. Minin and published by Springer Science & Business Media. This book was released on 2008-05-31 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antennas represent a critical technology in any of these wireless systems. Not only do they directly affect the received power of the system, they are also typically the largest and most visible part. Recently, the need for low-cost, low-profile, and lightweight antenna in the frequency range of the microwave/millimeter wave/THz band has regained momentum. "Basic Principles of Fresnel Antenna Arrays" provides us a with the basics of the various Fresnel Antenna approaches, in order to achieve low-cost, low-profile, and lightweight antenna in the microwave/millimeter wave band. A potential solution of the antenna problem lies in using lens technology in an array. The Fresnel zone plate lens (FZPL) antenna is in particular an interesting candidate for the array element. The limiting focusing properties of FZPL including subwave length focus are described in detail. The book further presents a novel hexagonal FZPL antenna which can be more effectively packed in an array due to its shape. Before considering the hexagonal FZPL antenna in an array, the authors investigate two ideas, described as methods to potentially improve the radiation characteristics. The first idea is to change the reference phase of the Fresnel zone radii - a novel free parameter in the usual design of zone plate’s lenses and antennas. To further improve the radiation characteristics of the hexagonal FZPL antenna, a technique involving Fresnel zone rotation is investigated. The book is of interest for designers of optical systems because, taking scaling effects into account, the characteristics of diffractive quasioptical elements are valid for diffractive focusing elements of integrated optics.
Download or read book Radiation Patterns in the Lower Ionosphere and Fresnel Zones for Elevated Antennas Over a Spherical Earth written by R. G. Merrill and published by . This book was released on 1962 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fresnel Zones in Wireless Links Zone Plate Lenses and Antennas written by H. D. Hristov and published by Artech House Publishers. This book was released on 2000 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whether you are an experienced electromagnetics specialist or a newcomer to the field, whether you need practical design guidelines or a clear and concise exposition of the fundamentals, you'll find this book invaluable. Written by an acknowledged expert, the volume includes a detailed description of the application of Fresnel zones to microwave wireless communication links as well as a comprehensive description of the state-of-the-art in newly created zone plate lens and antenna technologies. It also contains an overview of the basic electromagnetic equations for time harmonic fields, and a thorough treatment of the Fresnel-Kirchoff diffraction theory.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1984 with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earth station antenna measurements written by R G. Fitzgerald and published by . This book was released on 1977 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Government Research Reports written by and published by . This book was released on 1964 with total page 1416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Research of the National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1962 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Research written by United States. National Bureau of Standards and published by . This book was released on 1961 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Research of the National Bureau of Standards written by and published by . This book was released on 1961 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography and Index on Vacuum and Low Pressure Measurement written by William George Brombacher and published by . This book was released on 1961 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Monograph written by and published by . This book was released on 1959 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Passive Microwave Remote Sensing of the Earth written by Eugene A. Sharkov and published by Springer Science & Business Media. This book was released on 2003-12-16 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive description of the physical foundations of methods and instruments in the fields of passive remote sensing applied to investigations of the Earth, Solar system bodies and space. Emphasis is placed on the physical aspects necessary to judge the possibilities and limitations of passive remote sensing methods in specific observation cases. Numerous practical applications and illustrations are given referring to airspace up-to-date experiments. Due to the lack in traditional separation on methods and instruments of remote sensing of the Earth and outerterrestrial space this book aims to supply more information in this field.
Download or read book CWNA Certified Wireless Network Administrator Official Study Guide written by David D. Coleman and published by John Wiley & Sons. This book was released on 2009-12-15 with total page 751 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sybex is now the official publisher for CWNP, the certifying vendor for the CWNA program. This valuable guide covers all objectives for the newest version of the PW0-104 exam, including radio technologies; antenna concepts; wireless LAN hardware and software; network design, installation and management; wireless standards and organizations; 802.11 network architecture; wireless LAN security; performing site surveys; and troubleshooting. Also included are hands-on exercises, chapter review questions, a detailed glossary, and a pre-assessment test. The CD-ROM features two bonus exams, over 150 flashcards, and numerous White Papers and demo software. Note: CD-ROM materials for eBook purchases can be downloaded from CWNP’s website at www.cwnp.com/sybex.
Download or read book Digital Microwave Communication written by George Kizer and published by John Wiley & Sons. This book was released on 2013-05-22 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book to cover all engineering aspects of microwave communication path design for the digital age Fixed point-to-point microwave systems provide moderate-capacity digital transmission between well-defined locations. Most popular in situations where fiber optics or satellite communication is impractical, it is commonly used for cellular or PCS site interconnectivity where digital connectivity is needed but not economically available from other sources, and in private networks where reliability is most important. Until now, no book has adequately treated all engineering aspects of microwave communications in the digital age. This important new work provides readers with the depth of knowledge necessary for all the system engineering details associated with fixed point-to-point microwave radio path design: the why, what, and how of microwave transmission; design objectives; engineering methodologies; and design philosophy (in the bid, design, and acceptance phase of the project). Written in an easily accessible format, Digital Microwave Communication features an appendix of specialized engineering details and formulas, and offers up chapter coverage of: A Brief History of Microwave Radio Microwave Radio Overview System Components Hypothetical Reference Circuits Multipath Fading Rain Fading Reflections and Obstructions Network Reliability Calculations Regulation of Microwave Radio Networks Radio Network Performance Objectives Designing and Operating Microwave Systems Antennas Radio Diversity Ducting and Obstruction Fading Digital Receiver Interference Path Performance Calculations Digital Microwave Communication: Engineering Point-to-Point Microwave Systems will be of great interest to engineers and managers who specify, design, or evaluate fixed point-to-point microwave systems associated with communications systems and equipment manufacturers, independent and university research organizations, government agencies, telecommunications services, and other users.
Download or read book Radio Wave Propagation Fundamentals Second Edition written by Artem Saakian and published by Artech House. This book was released on 2020-12-31 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This completely updated second edition of an Artech House classic provides a thorough introduction to the basic principles of electromagnetic wave propagation of radio frequencies in real-world conditions, fully updated by including new achievements in theory and technology. It serves as an invaluable daily reference for practitioners in the field and as a complete, organized text on the subject. This comprehensive resource covers a wide range of essential topics, from the classification of radio waves, electromagnetic wave theory, and antennas for RF radio links, to the impact of the earth surface on the propagation of ground waves, atmospheric affects in radio wave propagation, and radio wave reception. The book explores the propagation of the ground radio waves, namely the waves that propagate in vicinity of the earth's surface (e.g., guided by that interface), without involvement of any atmospheric effects. Specifics of the high-frequency (HF) radio propagation due to reflections from ionospheric layers is studied, based on commonly used models of the ionospheric vertical profiles. Scattering of the radio waves of UHF and higher frequency bands from the random variations of the tropospheric refraction index (from tiny air turbulences) are also considered by using the principles of statistical radio-physics. Analysis of propagation conditions on real propagation paths, including analysis of the power budget of the VHF/UHF link to assure its stability (percentage of availability within observation time frame), terrestrial, broadcast, mobile, and satellite RF links are presented. The engineering design of the cellular networks, including LTE 4G, 5G and upcoming higher generations is explored. HF propagation predictions for extremely long-range links design for commercial and military applications are explained. Packed with examples and problems, this book provides a theoretical background for astrophysical, aeronomy and geophysical instrumentation design.
Download or read book Radio Techniques for Probing the Terrestrial Ionosphere written by Robert D. Hunsucker and published by Springer Science & Business Media. This book was released on 2013-03-07 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the years since the pioneering efforts of Sir Edward Appleton, M. A. F. Barnett, G. Breit, and M. A. Thve, many radio techniques have been employed to investigate the terrestrial ionosphere. The purposes of this book are to exam ine the basic physical interaction process of radio waves with the ionosphere, scrutinize each of the radio techniques currently in use, and describe the elements of each technique, as well as assess their capabilities and limitations. I have included some of the history of each technique, since we often tend to forget the efforts of the "pioneers". The interaction of radio waves with the terrestrial ionosphere has been described in considerable detail in several "classic" treatments, e.g., Ratcliffe (1959), Al'pert (1963), Budden (1961) and Davies (1965), Rishbeth and e.g., Flock (1979), Davies Garriott (1969), and in other more recent books, (1990), Hargreaves (1979), and Budden (1985). A few of the radio techniques have been described by Hargreaves (1979) and a book by Giraud and Petit (1978) has also included discussion of several of the techniques. The "WITS" handbook No. 2 (1989) also contains description of several radio techniques.
