Thin Impedance Vibrators
Thin Impedance Vibrators

Author: Mikhail V. Nesterenko

Publisher: Springer Science & Business Media

Published: 2011-02-01

Total Pages: 234

ISBN-13: 144197850X

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The book is devoted to exploring the foundations of the theory of thin impedance vibrator antennas. The text provides a continuation of the classic theory of thin perfectly conducting vibrators. Many consider impedance conception one of the most universal models in the theory of wave processes, as it informs such a wide spectrum of uses in solving practical problems of electrodynamics. This topic provides an opportunity to further search analytical solutions, allowing a simplification of the mathematical formulation of the boundary problem. The theory strives to widen the boundaries of the impedance vibrator antennas application in complex modern radio-and-electronic systems and devices. The results of much original research conducted by the authors will be useful for practicing engineers and designers of antenna and waveguide systems. The book is written in an academic style, and can be used to teach students and post graduates about radiotechnical and radiophysical specialities. The conclusion of the book lists many actual applied problems, which can provide inspiration for several potential PhD projects. Topics covered in this book are: •general questions of the theory of impedance vibrators in the spatial-frequency representation •electromagnetic waves radiation by impedance vibrators in free space and material mediums •electromagnetic waves radiation by impedance vibrators in material mediums over the perfectly conducting plane •electromagnetic waves scattering by irregular impedance vibrators in free space •generalized method of induced electromotive forces for investigation of the characteristics of impedance vibrators •radiation of electromagnetic waves by radial impedance vibrators on the perfectly conducting sphere •electromagnetic waves scattering by impedance vibrators in the rectangular waveguide

Combined Vibrator-Slot Structures: Theory and Applications
Combined Vibrator-Slot Structures: Theory and Applications

Author: Mikhail V. Nesterenko

Publisher: Springer Nature

Published: 2020-11-27

Total Pages: 337

ISBN-13: 3030601773

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The book presents solutions to a complex of internal and external problems of electromagnetics associated with the development of theory, construction of mathematical models and the development of rigorous methods for calculating the electrodynamic characteristics of combined vibrator-slot structures. The solutions of problems for determining the characteristics of impedance vibrator and slot radiators with arbitrary geometric and electrophysical parameters presented in the monograph were obtained within the framework of the unified methodological approach to construct asymptotic solutions of integral equations on currents and their systems. This approach made it possible to study a number of new combined vibrator-slot structures. The research results reveal the possibilities of using such structures as basic elements in the creation of modern antenna-waveguide devices operating in the ranges from meter to millimeter wavelengths, with new technical characteristics and functional purpose. The book is intended for senior and postgraduate students and researchers working in the fields of radiophysics, radio engineering and antenna-feeder design. The book covers the following topics: • excitation of electromagnetic waves in volumes with coordinate boundaries;• general issues of the theory of thin impedance vibrators and narrow slots in a spatial-frequency representation;• solution of current equations for isolated vibrator and slot scatterers;• combined radiating vibrator-slot structures in rectangular waveguide;• T-junctions of rectangular waveguides with vibrator-slot structures in coupling areas;• waveguide radiation of the combined vibrator-slot structures;• combined vibrator-slot structures located on a perfectly conducting sphere;• combined vibrator-slot Radiators in antenna arrays;• ultrawideband vibrator-slot structures;

Advanced Electromagnetic Waves
Advanced Electromagnetic Waves

Author: Saad Bashir

Publisher: BoD – Books on Demand

Published: 2015-11-18

Total Pages: 280

ISBN-13: 9535122053

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This book endeavors to give the reader a strong base in the advanced theory of electromagnetic waves and its applications, while keeping pace with research in various other disciplines that apply electrostatics/electrodynamics theory. The treatment is highly mathematical, which tends to obscure the principles involved.

Electromagnetic Fields Excited in Volumes with Spherical Boundaries
Electromagnetic Fields Excited in Volumes with Spherical Boundaries

Author: Yuriy M. Penkin

Publisher: Springer

Published: 2018-08-22

Total Pages: 207

ISBN-13: 3319978195

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This book discusses the problem of electromagnetic wave excitation in spatial regions with spherical boundaries and the accurate mathematical modeling based on numerical and analytical methods to significantly reduce the time required for developing new antenna devices. It particularly focuses on elements and systems on mobile objects of complex shape that are made of new technological materials. The experimental development of such devices and systems is an extremely time-consuming, lengthy, and expensive process. The book is intended for senior and postgraduate students and researchers working in the fields of radiophysics, radio engineering and antenna design. The authors assume that readers understand the basics of vector and tensor analysis, as well as the general theory of electrodynamics. The original results presented can be directly used in the development of spherical antennas and antenna systems for the mobile objects. The book addresses problems concerning the construction of Green’s functions for Hertz potentials in electrodynamic volumes with spherical boundaries, and solves these clearly and concisely. It also uses specific examples to analyze areas where the results could potentially be applied. The book covers the following topics: · excitation of electromagnetic fields in coordinate electrodynamic volumes; · Green’s functions for spherical resonators; · Green’s functions for infinite space outside of spherical scatterers; · electromagnetic fields of dipole radiators on spherical scatterers; · electromagnetic fields of thin radial impedance vibrators on perfectly conducting spheres; · electrodynamic characteristics of narrow slots in spherical surfaces; · multi-element and combined vibrator-slot radiators on spherical surfaces.

Antennas
Antennas

Author: Boris Levin

Publisher: CRC Press

Published: 2024-12-26

Total Pages: 537

ISBN-13: 1040302777

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This book describes both known and new results. In the sections devoted to the use of integral equations for the current in a linear metal radiator, the focus is on Leontovich's equation. An advantage of this equation is the simplicity of the solution and the absence of the argument φ in it because the integration over φ already performed. The refined solution makes it possible to determine the total sum of the series for the current, which is close to the known solution including only the first terms. The results of the synthesis of different types of antennas with capacitive loads are presented, which makes it possible to implement Hallen's hypothesis about the usefulness of applying such loads to create an in-phase current distribution in antennas and to obtain required characteristics. New results include the widespread use of the complex potential method in relation to the calculation of capacitive structures in homogeneous and inhomogeneous media, antenna patterns and flows of electrical fields between antenna elements and in the surrounding space. In particular, the analysis of field flows makes it possible to substantiate a rigorous method for analyzing microstrip antennas. The characteristics of antennas in various conditions of their installation are considered and compared. The results of the use of multi-floors structures that provide in the wide frequency range the radiation in direction perpendicular to the antenna axis, and structures that make it possible to reduce the mutual influence of antennas located at different heights on a common mast are described.

Wide-Range Antennas
Wide-Range Antennas

Author: Boris Levin

Publisher: CRC Press

Published: 2019-02-21

Total Pages: 204

ISBN-13: 1351043226

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Expanding the range of antenna frequency is the main objective of this book. Solutions proposed are based on the development of new theoretical methods for analyzing and synthesizing antennas. The book shows that concentrated capacitive loads connected along linear and V-antennas provide a high level of matching with a cable over a wide frequency range and improves directional characteristics of antennas, i.e. increases the communication distance. New theoretical methods are proposed for analysis and synthesis of antennas under consideration: 1) method of calculating directional characteristics of radiators with a given current distribution, and 2) method of electrostatic analogy for calculating mutual and total fields of complex multi-element radiating structures. These methods allow us to obtain optimal directional characteristics for director-type antennas (arrays of Yagi-Uda) and log-periodic antennas with concentrated capacitances and show that use of capacitors makes it possible to extend the frequency range of the director antennas and to decrease dimensions of the log-periodic antennas Multi-element (flat and three-dimensional) self-complementary antennas with different variants of connecting generator poles and cable wires to antenna elements are proposed, which improves the matching with a cable. Characteristics of flat structures are compared with characteristics of volume structures: conical, parabolic, and located on a pyramid edges. The book describes new versions of transparent antennas, antennas for cellular communication, multi-tier and multi-radiator antennas, and much more.

Semiconductor Nanotechnology
Semiconductor Nanotechnology

Author: Stephen M. Goodnick

Publisher: Springer

Published: 2018-07-26

Total Pages: 241

ISBN-13: 3319918966

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This book presents research dedicated to solving scientific and technological problems in many areas of electronics, photonics and renewable energy. Energy and information are interconnected and are essential elements for the development of human society. Transmission, processing and storage of information requires energy consumption, while the efficient use and access to new energy sources requires new information (ideas and expertise) and the design of novel systems such as photovoltaic devices, fuel cells and batteries. Semiconductor physics creates the knowledge base for the development of information (computers, cell phones, etc.) and energy (photovoltaic) technologies. The exchange of ideas and expertise between these two technologies is critical and expands beyond semiconductors. Continued progress in information and renewable energy technologies requires miniaturization of devices and reduction of costs, energy and material consumption. The latest generation of electronic devices is now approaching nanometer scale dimensions, new materials are being introduced into electronics manufacturing at an unprecedented rate, and alternative technologies to mainstream CMOS are evolving. Nanotechnology is widely accepted as a source of potential solutions in securing future progress for information and energy technologies. Semiconductor Nanotechnology features chapters that cover the following areas: atomic scale materials design, bio- and molecular electronics, high frequency electronics, fabrication of nanodevices, magnetic materials and spintronics, materials and processes for integrated and subwave optoelectronics, nanoCMOS, new materials for FETs and other devices, nanoelectronics system architecture, nano optics and lasers, non-silicon materials and devices, chemical and biosensors, quantum effects in devices, nano science and technology applications in the development of novel solar energy devices, and fuel cells and batteries.