Optimisation of Wire Antennas PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Optimisation of Wire Antennas PDF full book. Access full book title Optimisation of Wire Antennas by F. M. Landstorfer. Download full books in PDF and EPUB format.
Author: F. M. Landstorfer
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 200
Get Book Here
Book Description
After discussing the phenomenon of wave detachment and radiation within the nearfield of wire antennas in terms of fieldlines, instantaneous and time-average energy flow and Poynting vector ellipses, a new equivalent circuit is introduced which helps to describe and optimize short radiators. Numerical methods for shaping wire antennas for maximum performance are given. Parameters to be optimized are, for example, directivity and effective length. Numerous results for single and split-wire antennas with and without reflector, offering directivities ranging from 7 to 16 db, are presented. The results are also discussed in terms of nearfield properties. Methods for optimizing a combination of performance parameters such as directivity, sidelobe level and impedance are then presented, and results given. Arrays of these optimally shaped elements are combined in new backfire, Yagi-uda and LP antennas which offer surprising properties.
Author: F. M. Landstorfer
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 200
Get Book Here
Book Description
After discussing the phenomenon of wave detachment and radiation within the nearfield of wire antennas in terms of fieldlines, instantaneous and time-average energy flow and Poynting vector ellipses, a new equivalent circuit is introduced which helps to describe and optimize short radiators. Numerical methods for shaping wire antennas for maximum performance are given. Parameters to be optimized are, for example, directivity and effective length. Numerous results for single and split-wire antennas with and without reflector, offering directivities ranging from 7 to 16 db, are presented. The results are also discussed in terms of nearfield properties. Methods for optimizing a combination of performance parameters such as directivity, sidelobe level and impedance are then presented, and results given. Arrays of these optimally shaped elements are combined in new backfire, Yagi-uda and LP antennas which offer surprising properties.
Author: Derek Scott Linden
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 150
Get Book Here
Book Description
A Genetic Algorithm (GA) has been used in conjunction with the Numerical Electromagnetics Code, Version 2 (NEC2) to create and optimize atypical wire antenna designs with impressive characteristics. Antenna design parameters are encoded into an ordered series of numbers and/or symbols analogous to a biological chromosome. A cost function that quantifies how well a design meets the engineer's specifications is created. The GA uses these to generate and evaluate a population of designs. The most successful designs are then promoted and mixed through mating and mutation, while poor designs are removed. This process, difficult to trap in local minima, continues until convergence criteria are met, generally yielding excellent designs with no user intervention or initial guesses. Three antennas have been optimized: a monopole loaded with a modified folded dipole, the Yagi antenna, and the crooked-wire genetic antenna. Prior study of the loaded monopole had shown hemispherical coverage was possible. The GA found an asymmetric loaded monopole with an average variation in gain over the hemisphere of only 0.4dB, confirmed by measurement. GA-optimized Yagi antennas surpassed the gain of conventional Yagis by about 1dB, improvement also confirmed by measurement. The GA designed a Yagi with a beamwidth of 50 deg -60 deg, sidelobes nearly 25dB down, and a 14% bandwidth-specifications difficult to achieve using conventional techniques. The crooked-wire genetic antenna is several wires joined in series; locations and lengths are determined by the GA. Optimization for hemispherical coverage with right-hand circular polarization (RHCP) produced highly unusual shapes unrealizable using a conventional approach. RHCP hemispherical coverage was achieved with less than 4dB variation. Measurements verify the results.
Author: Debatosh Guha
Publisher: John Wiley & Sons
ISBN: 1119972981
Category : Technology & Engineering
Languages : en
Pages : 512
Get Book Here
Book Description
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.
Author: Warren L. Stutzman
Publisher: John Wiley & Sons
ISBN: 0470576642
Category : Technology & Engineering
Languages : en
Pages : 848
Get Book Here
Book Description
Stutzman's 3rd edition of Antenna Theory and Design provides a more pedagogical approach with a greater emphasis on computational methods. New features include additional modern material to make the text more exciting and relevant to practicing engineers; new chapters on systems, low-profile elements and base station antennas; organizational changes to improve understanding; more details to selected important topics such as microstrip antennas and arrays; and expanded measurements topic.
Author: Randy L. Haupt
Publisher: John Wiley & Sons
ISBN: 0470106271
Category : Science
Languages : en
Pages : 317
Get Book Here
Book Description
A thorough and insightful introduction to using genetic algorithms to optimize electromagnetic systems Genetic Algorithms in Electromagnetics focuses on optimizing the objective function when a computer algorithm, analytical model, or experimental result describes the performance of an electromagnetic system. It offers expert guidance to optimizing electromagnetic systems using genetic algorithms (GA), which have proven to be tenacious in finding optimal results where traditional techniques fail. Genetic Algorithms in Electromagnetics begins with an introduction to optimization and several commonly used numerical optimization routines, and goes on to feature: Introductions to GA in both binary and continuous variable forms, complete with examples of MATLAB(r) commands Two step-by-step examples of optimizing antenna arrays as well as a comprehensive overview of applications of GA to antenna array design problems Coverage of GA as an adaptive algorithm, including adaptive and smart arrays as well as adaptive reflectors and crossed dipoles Explanations of the optimization of several different wire antennas, starting with the famous "crooked monopole" How to optimize horn, reflector, and microstrip patch antennas, which require significantly more computing power than wire antennas Coverage of GA optimization of scattering, including scattering from frequency selective surfaces and electromagnetic band gap materials Ideas on operator and parameter selection for a GA Detailed explanations of particle swarm optimization and multiple objective optimization An appendix of MATLAB code for experimentation
Author: Andrew Lewis
Publisher: Springer Science & Business Media
ISBN: 3642012612
Category : Mathematics
Languages : en
Pages : 365
Get Book Here
Book Description
This book covers the latest theories, applications and techniques in Biologically-Inspired Optimisation Methods. Many chapters derive from studies presented at workshops and international conferences on e-Science, Grid Computing and Evolutionary computation.
Author: Branko D. Popović
Publisher: Taylor & Francis Group
ISBN:
Category : Computers
Languages : en
Pages : 352
Get Book Here
Book Description
A discourse on the computer-aided design of wire antennas, which provides numerous examples of the scope of CAD processes, including descriptions of the WireZeus-based CAD of antennas and related radiating structures, along with their matching networks.
Author: Matthew N.O. Sadiku
Publisher: CRC Press
ISBN: 1351365096
Category : Technology & Engineering
Languages : en
Pages : 687
Get Book Here
Book Description
This fourth edition of the text reflects the continuing increase in awareness and use of computational electromagnetics and incorporates advances and refinements made in recent years. Most notable among these are the improvements made to the standard algorithm for the finite-difference time-domain (FDTD) method and treatment of absorbing boundary conditions in FDTD, finite element, and transmission-line-matrix methods. It teaches the readers how to pose, numerically analyze, and solve EM problems, to give them the ability to expand their problem-solving skills using a variety of methods, and to prepare them for research in electromagnetism. Includes new homework problems in each chapter. Each chapter is updated with the current trends in CEM. Adds a new appendix on CEM codes, which covers commercial and free codes. Provides updated MATLAB code.
Author: F. M. Landstorfer
Publisher: *Research Studies Press
ISBN: 9780471907169
Category : Technology & Engineering
Languages : en
Pages : 0
Get Book Here
Book Description
This monograph provides the latest results on the nearfield of conventional straight-lined dipoles and monopoles. Shows the capabilities of optimization techniques for synthesizing curvilinear antennas which have unconventional geometries and surprising qualities. Presents applications of these techniques to multiwire structure yields, new types of backfire antennas and Yagi-Uda arrays. The computational methods used have been carefully selected so that effort and computer time are minimized without sacrificing accuracy.
Author: Branko D. Popović
Publisher: IET
ISBN: 9780852968079
Category : Technology & Engineering
Languages : en
Pages : 214
Get Book Here
Book Description
Describes a novel, general entire-domain method for the analysis of metallic antennas and scatterers that enables a very wide range of problems to be solved using computers of relatively modest capability. The conventional approximation approach requires a large amount of computer storage. Of interest to engineers, scientists, and graduate students engaged in the analysis or design of electrically small and medium-sized antennas and scatterers. Distributed by INSPEC. Annotation copyright by Book News, Inc., Portland, OR
