Download or read book Phased Array Antenna Pattern Optimization with Failed Elements written by B. F Collins (II.) and published by . This book was released on 1987 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses several methods of optimizing the pattern of a phased array antenna. Two methods, the gradient search algorithm method and the null displacement technique were shown to be applicable to optimizing a phased array with failed elements. The results of the study show how the pattern can be optimized depending on the scalar cost function and constraints chosen and what effects varying the complex weight of the array elements has on the pattern.

Download or read book Optimization of the Antenna Pattern of a Phased Array with Failed Elements written by and published by . This book was released on 1986 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using a phased array antenna on a system can add dimensions of flexibility and control. By varying the phase and amplitude of the current exciting each element, the far field antenna pattern can be modified in such a way as to obtain a desired, optimal pattern. The purpose of this thesis is to develop a rapid compensation method for any element failures by varying the currents exciting the remaining elements. Although many methods for optimizing the pattern of a full array are available, this work is unique because it develops methods of finding the optimum pattern of an array which contains failed or missing elements. Optimization methods in the literature which were investigated include thinned array analysis, adaptive array analysis, eigenvalue methods, null displacement techniques, and assorted iterative techniques. Another method discussed in this thesis, the direct technique, originated from the need for a quick optimization method, especially when very large arrays are used. (Thesis).

Download or read book Array Pattern Optimization written by Jafar Ramadhan Mohammed and published by BoD – Books on Demand. This book was released on 2019-03-27 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Array pattern optimization is a very important and necessary issue in the majority of modern communication systems in a variety of applications such as sonar, radar, navigation, wireless communications, and many other engineering fields. Classical methods for array pattern synthesis have worked mainly with analytical models that are linear, local and, thus, their performances were not optimum. They have always been designed with closed-form mathematical models. Unlike these analytical methods, the global optimization methods with powerful computing tools offer optimum solutions. During the last few years, the design of the antenna arrays has been a topic of significant research activity. This book presents recent advances in the field of array pattern optimization. It is targeted primarily toward students and researchers who want to be exposed to a wide variety of antenna array design and optimization. It includes five chapters as well as the introductory chapter. These five chapters are categorized into five different areas depending on the application. These applications are ordered to address interference suppression, electronic toll collection, mmWave and ultra-wideband, integrated antennas, and educational packages for modeling smart antenna for 5G wireless communications. The book has the advantage of providing a collection of applications that are entirely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity.

Download or read book Phased Array Antennas with Optimized Element Patterns written by Sergei P. Skobelev and published by Artech House. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative resource provides you with a detailed description of ideal array element characteristics that help you estimate the quality of development of real-world phased array antennas. You find several approaches to optimum phased array design, allowing you to provide specified array gain in a specific region of scan, using a minimum number of expensive, controlled devices. Moreover, this practical book presents important numerical methods that you can use to model and optimize phased array structure to obtain the best array characteristics that the chosen structure can provide.From arrays with beam-forming networks, arrays of coupled dual-mode waveguides, and arrays with reactively loaded radiators, to waveguide arrays with protruding dielectric elements, and arrays with strip, disk, and wire structures, this comprehensive reference explains a wide range of essential topics to help you with work in this challenging area. The book is supported with over 165 illustrations and more than 566 equations.

Download or read book Optimization of the Antenna Pattern of a Phased Array with Faled Elements written by Bernard F. Collins (CAPT, USAF., II) and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation based Optimization Of Antenna Arrays written by Slawomir Koziel and published by World Scientific. This book was released on 2019-02-13 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book addresses surrogate-assisted design of antenna arrays, in particular, how surrogate models, both data-driven and physics-based, can be utilized to expedite procedures such as parametric optimization, design closure, statistical analysis, or fault detection. Algorithms and design frameworks are illustrated using a large variety of examples including real-world printed-circuit antenna and antenna array structures.This unique compendium contains introductory materials concerning numerical optimization, both conventional (gradient-based and derivative-free, including metaheuristics) and surrogate-based, as well as a considerable selection of customized procedures developed specifically to handle antenna array problems. Recommendations concerning practical aspects of surrogate-assisted multi-objective antenna optimization are also given. The methods presented allow for cost-efficient handling of antenna array design problems (involving CPU-intensive EM models) in the context of design optimization and statistical analysis, which will benefit both researchers, designers and graduate students.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 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.

Download or read book Element Failure Correction of Linear Array Using Hybrid Computing written by Nasir Ammar and published by LAP Lambert Academic Publishing. This book was released on 2015-06-17 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distorted beam pattern in array antenna is due to failure of one are more elements in array. Correction in beam pattern is done either through readjusting the weights of remaining healthy array elements or by readjusting phase. Readjusting phase put restriction beam steering which is unacceptable. We can easily correct faulty array pattern without paying much cost by readjustment of weights by different optimization techniques. In this work a new optimization hybrid technique based on firefly & harmony search algorithm in LAA. This optimization algorithm has provided fast and more accurate result in correction as compare to individual firefly and harmony search. This hybrid algorithm has a firefly algorithm feature of finding local maxima in less time and then finding optimum solution from these local maxima by using harmony search algorithm. It is fast enough to be implemented practically. I am proposing to use this hybrid algorithm in 2-diminsional LAA (circular or rectangular) or other type of array antennas. I am also proposing to check this algorithm in more than one faulty element in Linear Antenna Array.

Download or read book Phased Array Antenna Handbook Third Edition written by Robert J. Mailloux and published by Artech House. This book was released on 2017-11-30 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: This completely revised third edition of an Artech House classic, Phased Array Antenna Handbook, Second Edition, offers an up-to-date and comprehensive treatment of array antennas and systems. This edition provides a wealth of new material, including expanded coverage of phased array and multiple beam antennas. New modern machine learning techniques used for analysis are included. Additional material on wideband antennas and wideband coverage in array antennas are incorporated in this book, including new methods, devices, and technologies that have developed since the second edition. A detailed treatment of antenna system noise, sections on antenna pattern synthesis, developments in subarray technology, and in-depth coverage of array architecture and components are additional new features of this book. The book explores design elements that demonstrate how to size an array system with speed and confidence. Moreover, this resource provides expanded coverage of systems aspects of arrays for radar and communications. Supported with numerous equations and illustrations, this practical book helps evaluate basic antenna parameters such as gain, sidelobe levels, and noise. Readers learn how to compute antenna system noise, design subarray geometries for given bandwidth, scan and sidelobe constraints, and choose array illumination tapers for given sidelobe levels.

Download or read book Analysis and Design of Transmitarray Antennas written by Ahmed H. Abdelrahman and published by Springer Nature. This book was released on 2022-06-01 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, transmitarray antennas have attracted growing interest with many antenna researchers. Transmitarrays combines both optical and antenna array theory, leading to a low profile design with high gain, high radiation efficiency, and versatile radiation performance for many wireless communication systems. In this book, comprehensive analysis, new methodologies, and novel designs of transmitarray antennas are presented. Detailed analysis for the design of planar space-fed array antennas is presented. The basics of aperture field distribution and the analysis of the array elements are described. The radiation performances (directivity and gain) are discussed using array theory approach, and the impacts of element phase errors are demonstrated. The performance of transmitarray design using multilayer frequency selective surfaces (M-FSS) approach is carefully studied, and the transmission phase limit which are generally independent from the selection of a specific element shape is revealed. The maximum transmission phase range is determined based on the number of layers, substrate permittivity, and the separations between layers. In order to reduce the transmitarray design complexity and cost, three different methods have been investigated. As a result, one design is performed using quad-layer cross-slot elements with no dielectric material and another using triple-layer spiral dipole elements. Both designs were fabricated and tested at X-Band for deep space communications. Furthermore, the radiation pattern characteristics were studied under different feed polarization conditions and oblique angles of incident field from the feed. New design methodologies are proposed to improve the bandwidth of transmitarray antennas through the control of the transmission phase range of the elements. These design techniques are validated through the fabrication and testing of two quad-layer transmitarray antennas at Ku-band. A single-feed quad-beam transmitarray antenna with 50 degrees elevation separation between the beams is investigated, designed, fabricated, and tested at Ku-band. In summary, various challenges in the analysis and design of transmitarray antennas are addressed in this book. New methodologies to improve the bandwidth of transmitarray antennas have been demonstrated. Several prototypes have been fabricated and tested, demonstrating the desirable features and potential new applications of transmitarray antennas.

Download or read book Array and Phased Array Antenna Basics written by Hubregt J. Visser and published by John Wiley & Sons. This book was released on 2006-02-03 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting a growing interest in phased array antenna systems, stemming from radar, radio astronomy, mobile communications and satellite broadcasting, Array and Phased Array Antenna Basics introduces the principles of array and phased array antennas. Packed with first-hand practical experience and worked-out examples, this is a valuable learning tool and reference source for those wishing to improve their understanding of basic array antenna systems without relying heavily on a thorough knowledge of electromagnetics or antenna theory. Features a general introduction to antennas and explains the array antenna principle through discussion of the physical characteristics rather than the theory Explores topics often not covered in antenna textbooks, such as active element pattern, array feeding, means of phase changing, array antenna characterisation, sequential rotation techniques and reactively loaded arrays Guides the reader through the necessary mathematics, allowing them to move onto specialist books on array and phased array antennas with a greater understanding of the topic Supported by a companion website on which instructors and lecturers can find electronic versions of the figures An ideal introduction for those without a background in antennas, this clear, concise volume will appeal to technicians, researchers and managers working in academia, government, telecommunications and radio astronomy. It will also be a valuable resource for professionals and postgraduates with some antenna knowledge.

Download or read book Optimization of Antenna Arrays by Simulated Annealing written by Víctor Jaime De la Rosa Pérez and published by . This book was released on 2005 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gain of Phased Array Antennas Under Small Random Errors in Element Placement written by Patrick Marron and published by . This book was released on 2014 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: A phased array is an arrangement of antennas whose emergent radiation pattern is controlled by the relative phases of the signals that are feeding its elements. Within implementation limits, the effective radiation pattern of the array is reinforced in a certain desired direction and repressed in other undesired directions. The pattern can thus be steered by introducing a relative phase shift between its elements so that its radiation adds constructively in a certain direction. This mechanism also means that error in the relative spacing between the elements of an array is likely to result in an error in the phase and a decrease in the gain of the array in the desired direction. The effects of element spacing error in phased array systems have been studied extensively. The approach in most studies was to show rst that errors in the relative spacing of the elements results in error in the relative phase between the elements, then to characterize the distribution of the resulting gain. Often it was assumed that there are many elements in the array, and mathematical limits were used to calculate the radiation pattern under a large array assumption. Like most studies of the subject, we rst quantize how errors in the relative spacing of the elements a ect the error in the relative phase between the elements. We use a small-error assumption that is realistic in planned deterministic phased arrays. However, we do not make the assumption of a large number of elements in the array and our results are applicable to small arrays as well. We show that the gain loss can be approximated by the sum of the squares of the relative phase of each element with a scaling factor. Thus whenever the relative phase of each element is normally distributed with zero mean, the gain loss is distributed as a gamma distribution. Our key result is an expression for the allowed variance in the element position as a function of gain loss, the number of elements of the array, and the probability that this gain loss is realized. Using the expression a designer can specify placement tolerance as a function of the quality (in terms of gain in the desired direction) of the array. We use the expression for the element position variance to study the design of uniform linear arrays, uniform rectangular arrays, and uniform circular arrays. Simulations demonstrate that our derived distribution for the gain loss is very close to the expected distribution.

Download or read book Air University Abstracts of Research Reports written by and published by . This book was released on 1986 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Socio cultural Inspired Metaheuristics written by Anand J. Kulkarni and published by Springer. This book was released on 2019-03-29 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest insights and developments in the field of socio-cultural inspired algorithms. Akin to evolutionary and swarm-based optimization algorithms, socio-cultural algorithms belong to the category of metaheuristics (problem-independent computational methods) and are inspired by natural and social tendencies observed in humans by which they learn from one another through social interactions. This book is an interesting read for engineers, scientists, and students studying/working in the optimization, evolutionary computation, artificial intelligence (AI) and computational intelligence fields.

Download or read book Gain Optimization for Arbitrary Antenna Arrays Subject to Random Fluctuations written by Fung-I. Tseng and published by . This book was released on 1967 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Metaheuristics written by Seyedali Mirjalili and published by Elsevier. This book was released on 2023-01-31 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Metaheuristics: Algorithms and Applications presents the foundational underpinnings of metaheuristics and a broad scope of algorithms and real-world applications across a variety of research fields. The book starts with fundamentals, mathematical prerequisites, and conceptual approaches to provide readers with a solid foundation. After presenting multi-objective optimization, constrained optimization, and problem formation for metaheuristics, world-renowned authors give readers in-depth understanding of the full spectrum of algorithms and techniques. Scientists, researchers, academicians, and practitioners who are interested in optimizing a process or procedure to achieve a goal will benefit from the case studies of real-world applications from different domains. The book takes a much-needed holistic approach, putting the most widely used metaheuristic algorithms together with an in-depth treatise on multi-disciplinary applications of metaheuristics. Each algorithm is thoroughly analyzed to observe its behavior, providing a detailed tutorial on how to solve problems using metaheuristics. New case studies and research problem statements are also discussed, which will help researchers in their application of the concepts. Presented by world-renowned researchers and practitioners in metaheuristics Includes techniques, algorithms, and applications based on real-world case studies Presents the methodology for formulating optimization problems for metaheuristics Provides readers with methods for analyzing and tuning the performance of a metaheuristic, as well as for integrating metaheuristics in other AI techniques Features online complementary source code from the applications and algorithms