Download or read book Ground Loss Reduction at High Frequencies Through the Use of Antenna Arrays written by C. M. De Santis and published by . This book was released on 1971 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: High frequency antenna arrays are shown to reduce the effect of conduction losses normally associated with an antenna operating on or in proximity to the surface of the earth. It is demonstrated that the normal directivity gain as a function of array element spacing is modified by the presence of the finite conducting earth, and that at the lower frequencies in the HF range the gain of the array increases rapidly as the element spacing is increased from zero (single dipole) to about 1/10 of a wavelength. At this spacing, the gain approaches a limit which for low conductivities is close to a theoretical upper bound equal to the number of elements in the array. (Author).

Download or read book Experimental Investigation of High Frequency Antenna Arrays Having Reduced Ground Losses written by D. V. Campbell and published by . This book was released on 1972 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact, high frequency antennas have been combined to form efficient, closely-spaced arrays having greatly reduced ground losses. Under ideal circumstances, an array of N elements would reduce the ground loss by the factor 1/N. Experiments prove that only a small area is needed to erect an omnidirectional antenna array having significantly increased efficiency. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Radar Cross Section HIS Based Phased Array written by Hema Singh and published by CRC Press. This book was released on 2020-08-17 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and development of low radar cross section (RCS) phased array has been a challenging subject in stealth technology. The frequency selective surface elements act as absorbers in specific frequency band and facilitate gain enhancement and reduction of antenna RCS. This book presents a comprehensive EM design and analysis of such low-profile patch arrays with high impedance surface-based ground plane. It explains how to determine radiation mode RCS of low-profile antenna arrays with arbitrary configurations. Detailed descriptions of design, workflow of determining radiation and scattering behavior of antenna arrays have been supported with schematics, tables, and illustrations. Aimed at engineers and researchers for RCS, antenna engineers and graduate students in electrical engineering and electromagnetics, it • Discusses both radiation and scattering features of both planar and conformal HIS-based low profile antennas • Describes the theoretical background, design, simulations and analysis of low RCS phased array in detail • Presents the physics behind the resultant radiation and scattering characteristics of designed antenna array • Helps readers understand design and analysis of low RCS antenna array without any degradation in its radiation performance • Includes figures, schematics and illustrations to provide comprehensive descriptions of both radiation and scattering characteristics of phased arrays of different configurations

Download or read book Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications written by Yingjie Jay Guo and published by John Wiley & Sons. This book was released on 2021-10-26 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications Reviews advances in the design and deployment of antenna arrays for future generations of wireless communication systems, offering new solutions for the telecommunications industry Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications addresses the challenges in designing and deploying antennas and antenna arrays which deliver 6G and beyond performance with high energy efficiency and possess the capability of being immune to interference caused by different systems mounted on the same platforms. This timely and authoritative volume presents innovative solutions for developing integrated communications networks of high-gain, individually-scannable, multi-beam antennas that are reconfigurable and conformable to all platforms, thus enabling the evolving integrated land, air and space communications networks. The text begins with an up-to-date discussion of the engineering issues facing future wireless communications systems, followed by a detailed discussion of different beamforming networks for multi-beam antennas. Subsequent chapters address problems of 4G/5G antenna collocation, discuss differentially-fed antenna arrays, explore conformal transmit arrays for airborne platforms, and present latest results on fixed frequency beam scanning leaky wave antennas as well as various analogue beam synthesizing strategies. Based primarily on the authors’ extensive work in the field, including original research never before published, this important new volume: Reviews multi-beam feed networks, array decoupling and de-scattering methods Provides a systematic study on differentially fed antenna arrays that are resistant to interference caused by future multifunctional/multi-generation systems Features previously unpublished material on conformal transmit arrays based on Huygen’s metasufaces and reconfigurable leaky wave antennas Includes novel algorithms for synthesizing and optimizing thinned massive arrays, conformal arrays, frequency invariant arrays, and other future arrays Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications is an invaluable resource for antenna engineers and researchers, as well as graduate and senior undergraduate students in the field.

Download or read book Influence of Non Homogeneous Earth on the Performance of High Frequency Receiving Arrays with Electrically Small Ground Planes written by and published by . This book was released on 1991 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of ground-based frequency (HF) antenna arrays is reduced when the array elements have electrically-small ground planes. Performance degradations include: (1) a decrease in directive gain near the horizon (caused by earth multipath), (2) a decrease in radiation efficiency and an increase in internal noise (caused by ground losses), (3) an array RMS phase error (caused by exterior currents on element feed cables), and (4) an array rms phase error and beam pointing errors (caused by non-uniform Fresnel reflection RMS from a non-homogeneous earth). This paper models the degradation described in (4) above. Numerical results are presented for cases of randomly-distributed and systematically-distributed earth non-homogeneities where one-half of vertically-polarized array elements are located in proximity to one type of earth and the remaining half are located in proximity to a second type of earth. The maximum rms phase errors, for the cases examined, are 18 degrees and 9 degrees for randomly-distributed and systematically-distributed non-homogeneities, respectively. The maximum beam pointing errors are 0 and 0.3 beamwidths for randomly-distributed and systematically-distributed non-homogeneities, respectively.

Download or read book Terahertz Planar Antennas for Next Generation Communication written by Kumud Ranjan Jha and published by Springer Science & Business Media. This book was released on 2014-01-10 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes various methods to enhance the directivity of planar antennas, enabling the next generation of high frequency, wireless communication. The authors discuss various applications to the terahertz regime of the electromagnetic spectrum, with an emphasis on gain enhancement mechanisms. The numerical models of these antennas are presented and the analytical results are supported, using commercial simulators. The multilayer substrate microstrip transmission line at terahertz frequency is also explored and a method to obtain the various parameters of this interconnect at high frequency is described. This book will be a valuable resource for anyone needing to explore the terahertz band gap for future wireless communication, in an effort to solve the bandwidth (spectrum scarcity) problem.

Download or read book Monopole Antennas written by Melvin M. Weiner and published by CRC Press. This book was released on 2003-04-22 with total page 733 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides discussion of the modelling, testing and application of monopole antennas in free space and in proximity to flat earth, including topics on propagation, tuning stability, antenna range design, noise, ground-based high-frequency arrays, and electrically small antennas.

Download or read book The Telecommunications and Data Acquisition Progress Report written by and published by . This book was released on 1994-10 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Newnes Communications Technology Handbook written by Geoff Lewis and published by Elsevier. This book was released on 2013-10-22 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: Newnes Communications Technology Handbook provides a discussion on different topics relevant to communications technology. The book is comprised of 39 chapters that tackle a wide variety of concern in communications technology. The coverage of the text includes technologies, such as analog digital communications systems, radio frequency receiver, and satellite systems. The book also discusses some methods and techniques used in communications technology, including mixer signal processing, modulation and demodulation, and spread spectrum techniques. The text will be of great use to engineers, technicians, and professionals involved in telecommunications.

Download or read book Handbook of Metrology and Applications written by Dinesh K. Aswal and published by Springer Nature. This book was released on 2023-08-23 with total page 2504 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This handbook provides comprehensive and up-to-date information on the topic of scientific, industrial and legal metrology. It discusses the state-of-art review of various metrological aspects pertaining to redefinition of SI Units and their implications, applications of time and frequency metrology, certified reference materials, industrial metrology, industry 4.0, metrology in additive manufacturing, digital transformations in metrology, soft metrology and cyber security, optics in metrology, nano-metrology, metrology for advanced communication, environmental metrology, metrology in biomedical engineering, legal metrology and global trade, ionizing radiation metrology, advanced techniques in evaluation of measurement uncertainty, etc. The book has contributed chapters from world’s leading metrologists and experts on the diversified metrological theme. The internationally recognized team of editors adopt a consistent and systematic approach and writing style, including ample cross reference among topics, offering readers a user-friendly knowledgebase greater than the sum of its parts, perfect for frequent consultation. Moreover, the content of this volume is highly interdisciplinary in nature, with insights from not only metrology but also mechanical/material science, optics, physics, chemistry, biomedical and more. This handbook is ideal for academic and professional readers in the traditional and emerging areas of metrology and related fields.

Download or read book Future Trends in 5G and 6G written by Mangesh M. Ghonge and published by CRC Press. This book was released on 2021-12-30 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive overview of basic communication and networking technologies. It focuses on emerging technologies, such as Software-Defined Network (SDN)-based ad hoc networks, 5G, Machine Learning, and Deep Learning solutions for communication and networking, Cloud Computing, etc. It also includes discussions on practical and innovative applications, including Network Security, Smart Cities, e-health, and Intelligent Systems. Future Trends in 5G and 6G: Challenges, Architecture, and Applications addresses several key issues in SDN energy-efficient systems, the Internet of Things, Big Data, Cloud Computing and Virtualization, Machine Learning, Deep Learning, Cryptography, and 6G wireless technology and its future. It provides students, researchers, and practicing engineers with an expert guide to the fundamental concepts, challenges, architecture, applications, and state-of-the-art developments in communication and networking.

Download or read book An Introduction to Hard Ferrites written by Gagan Kumar Bhargava and published by Materials Research Forum LLC. This book was released on 2023-03-05 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their excellent magnetic characteristics, hard ferrites have many high-tech applications in such areas as permanent magnets, storage devices, HF Antenna and Spin Transmission. The present book reviews the present knowledge of these materials; their processing, characterization and potential applications. The book is also useful as an introductory text for students at the postgraduate research level. Keywords: Hard Ferrites, Synthesis, BaFe12O19, SrFe12O19, Magnetization, Miniaturization, EMI Shielding, Ferrofluids, Nanomaterials, Nano-Floating Gate, Permanent Magnets, Recording Media, High-Frequency Antenna, Radar Applications, Memory Devices. Spin Transmission, Spinel Model, Synthesis Methods.

Download or read book Government Reports Announcements written by and published by . This book was released on 1974 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metamaterial written by Xun-Ya Jiang and published by BoD – Books on Demand. This book was released on 2012-05-16 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: In-depth analysis of the theory, properties and description of the most potential technological applications of metamaterials for the realization of novel devices such as subwavelength lenses, invisibility cloaks, dipole and reflector antennas, high frequency telecommunications, new designs of bandpass filters, absorbers and concentrators of EM waves etc. In order to create a new devices it is necessary to know the main electrodynamical characteristics of metamaterial structures on the basis of which the device is supposed to be created. The electromagnetic wave scattering surfaces built with metamaterials are primarily based on the ability of metamaterials to control the surrounded electromagnetic fields by varying their permeability and permittivity characteristics. The book covers some solutions for microwave wavelength scales as well as exploitation of nanoscale EM wavelength such as visible specter using recent advances of nanotechnology, for instance in the field of nanowires, nanopolymers, carbon nanotubes and graphene. Metamaterial is suitable for scholars from extremely large scientific domain and therefore given to engineers, scientists, graduates and other interested professionals from photonics to nanoscience and from material science to antenna engineering as a comprehensive reference on this artificial materials of tomorrow.

Download or read book Array Beamforming Enabled Wireless Communications written by Zhenyu Xiao and published by CRC Press. This book was released on 2023-04-25 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates the most advanced theories and methodologies of array beamforming, with a focus on antenna array enabled wireless communication technology. Combining with the current development needs and trends of wireless communication technology around the world, the authors explore the potentials and challenges of large-scale antenna array beamforming technology in next-generation mobile communication and some important emerging application scenarios. The book first introduces the basic structure of antenna array hierarchical codebook and channel estimation with high dimensionality, with which the time cost of searching the channel information can be effectively reduced. It then explicates high-efficiency beamforming transmission methods for point-to-point transmission, full-duplex point-to-point transmission, and point-to-multipoint transmission where array beamforming enabled non-orthogonal multiple access (NOMA) technologies for typical two-user systems and general multi-user systems are emphasized. The book also discusses array beamforming enabled unmanned aerial vehicle (UAV) communications and array beamforming enabled space/air/ground communications, with the uniqueness and relative solutions for single UAV systems and multi-UAV networks being analyzed. This will be a vital reference for researchers, students, and professionals interested in wireless communications, array beamforming, and millimeter-wave communications.

Download or read book Aviation Electronics Technician 1 C written by United States. Bureau of Naval Personnel and published by . This book was released on 1968 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: