Download or read book Overlapped Sub Array Scanning Antenna Study written by G. Ploussios and published by . This book was released on 1979 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report refers to an investigation of new phased array techniques using overlapping multiple beam elements. It is shown that this technique, can be applied to a wide variety of electronically scanned system requirements. Two designs, one for limited scan and the other for wide angle scan with a minimum number of elements and phase shifters were selected for the reported computer analysis. The results indicate extremely low sidelobe levels over most of the angular sector while limiting the close-in sidelobes to no more than -20 dB and grating lobe levels to peak values of about -14 dB for some scan locations. The limited scan design utilizes 18 eight-port Bulter matrices, 18 phase shifters, and 9 SP2T switches to achieve 20 BW's of a + or - 10 deg. scan. The wide-angle design provides 90 BW's of scan + or - 45 deg.) with 26 eight-port matrix elements, 26 phase shifters and 26 SP4T switches. The analysis of the new scan array technique indicates that the array performance can be further improved at the cost of additional elements and element complexity.
Download or read book An Overlapped Sub array for Limited Scan Application written by Robert J. Mailloux and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report describes a new technique for producing an overlapped sub-array pattern by higher order mode coupling between nearest neighbor phased array elements. Theoretical and experimental results are compared, and practical circuits described for one plane of scan. The Appendix presents a circuit for scanning in two planes. (Author).
Download or read book Study of the Radiation Properties of Overlapped Subarrayed Scanning Antennas written by Ronald Louis Fante and published by . This book was released on 1979 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radar systems of the future will require wideband electronically steered antennas, with sidelobes below -40 dB. Because the cost of a fully time-delay steered array is excessive, the concept of overlapped subarray (with time delay controlled at the subarray feed input) is attractive. This concept seems to have originated with Rudge and Whithers, and Tang, and recently studied for limited scan by Borgiotti. In this paper we will study the sidelobe and bandwidth properties of this system for large scan angles. The basic configuration uses a circular lens fed by a hybrid matrix (with fixed time delays at the matrix output for subarray beam collimation). When an input port on the feed is excited, a distinct subarray distribution is produced on the output face of the lens. Therefore different time delays can be applied to each subarray simply by applying different time delays to each input port. The main array has phase shifters to produce a phase tilt that scans the subarray patterns. (Author).
Download or read book Electronically Scanned Arrays written by Robert J. Mailloux and published by Morgan & Claypool Publishers. This book was released on 2007 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a compact but comprehensive treatment of the scanned array, from the underlying basis for array pattern behaviour to the engineering choices leading to successful design. The book describes the scanned array in terms of radiation from apertures and wire antennas and introduces the effects resulting directly from scanning.
Download or read book A Compact Fully Overlapping Subarray Antenna written by P. A. Valentino and published by . This book was released on 1984 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes a new limited scan antenna technique for electronic scanning arrays. The antenna uses a novel coupling network to achieve fully overlapping subarrays with minimal antenna depth. The coupling network is comprised of contraposed input and output ports interconnected through a one wavelength section of radial waveguide. Antenna and network design principles are discussed in detail. Performance parameters are defined and the major features of the design including very low sidelobe and adaptive nulling capabilities are presented. An experimental demonstration antenna is described, and experimental results for the antenna and coupling network demonstrating the capabilities of the design are presented. (Author).
Download or read book An Overlapped Sub array for Limited Scan Application written by Robert J. Mailloux and published by . This book was released on 1973 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report describes a new technique for producing an overlapped sub-array pattern by higher order mode coupling between nearest neighbor phased array elements. Theoretical and experimental results are compared, and practical circuits described for one plane of scan. The Appendix presents a circuit for scanning in two planes. (Author)
Download or read book Improved Sidelobe Performance of Array Antennas with the Use of Overlapping Sub array Architecture written by S. R. Rengarajan and published by . This book was released on 2000 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Array antennas with sub-array architecture are frequently employed in phased array systems. However, the sub-array architecture can introduce severe pattern degradation in the form of higher sidelobes that arise as the frequency is changed or when multiple beams are generated by combining outputs of sub-arrays with a digital beam former. This report presents results of an investigation on the use of overlapping sub-arrays for improving the sidelobe performance.
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 549 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 Design Criteria and Numerical Simulation of an Antenna System for One dimensional Limited Scan written by Giorgio V. Borgiotti and published by . This book was released on 1975 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical and numerical study was performed on a novel design scheme for an antenna for limited one-dimensional scan. The system has a number of control elements approximately equal to the minimum that are theoretically compatible with the aperture size and field of view (FOV). The radiating structure consists of a 'boot lace' lens with linear outer and circular inner profiles. This geometry plays a basic role in determining excellent scan performance over a moderate frequency band. A linear array whose size depends critically upon scan requirements and the lens focal length is located on the focal plane and is focussed onto the inner lens profile. The array is fed by a Hybrid Network (HN) performing a spatial Fourier transformation. The input ports of the HN are fed by the output ports of a Beam Forming Network (BFN) through a set of variable phase shifters. The BFN has separate input ports for the sum and difference patterns controlled independently. The system works as follows. The antenna illumination is synthesized as the weighted superposition of components illuminations or 'overlapping subarrays', each of which is due to the excitation of one of the ports of the HN. The amplitudes of the subarray excitations are fixed and determined by the power divisions provided by the BFN. Their phases are controlled by the set of variable phase shifters. A desirable feature of the scheme is that for fixed phase shifter settings, neither the beam scans nor the width changes for a moderate frequency variation.
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronically Scanned Arrays written by Robert J. Mailloux and published by Morgan & Claypool Publishers. This book was released on 2007-12-01 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scanning arrays present the radar or communications engineer with the ultimate in antenna flexibility. They also present a multitude of new opportunities and new challenges that need to be addressed. In order to describe the needs for scanned array development, this book begins with a brief discussion of the history that led to present array antennas. This text is a compact but comprehensive treatment of the scanned array, from the underlying basis for array pattern behavior to the engineering choices leading to successful design. The book describes the scanned array in terms of radiation from apertures and wire antennas and introduces the effects resulting directly from scanning, including beam broadening, impedance mismatch and gain reduction and pattern squint and those effects of array periodicity including grating and quantization lobes and array blindness. The text also presents the engineering tools for improving pattern control and array efficiency including lattice selection, subarrray technology and pattern synthesis. Equations and figurers quantify the phenomena being described and provide the reader with the tools to tradeoff various performance features. The discussions proceed beyond the introductory material and to the state of the art in modern array design. Contents: Basic Principles and Applications of Array Antennas / Element Coupling Effects in Array Antennas / Array Pattern Synthesis / Subarray Techniques for Limited Field of View and Wide Band Applications
Download or read book Array Techniques for Limited Scan Application written by Robert J. Mailloux and published by . This book was released on 1972 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of techniques are described which allow the use of large array elements or sub-arrays for limited scan application. Some of these techniques are new and so are described in sufficient detail to predict their performance. Emphasis is placed mainly on the method called odd-mode-scanning; the treatment of other techniques are included to add background for evaluating this new method. (Author).
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 Overlapped Subarraying Techniques written by Paul R. Caron and published by . This book was released on 1980 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: In applications of phased array antennas for limited scan, sub-array schemes prove to be useful in reducing costs and space. An investigation of two such techniques, namely the space fed lens and a constrained feed system were conducted. Radiation patterns for a flat space-fed lens have been obtained and it has been shown that this system compares favorably in performance with the spherical lens, the latter being more difficult and expensive to construct in a space environment. Results on the effects of surface perturbations in the lens and on techniques for phase correcting at the feed for these are presented. (Author).
Download or read book A Limited scan Antenna Comprised of a Microwave Lens and Phased array Feed written by Robert V. McGahan and published by . This book was released on 1975 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Limited-scan antennas are finding increasing use in satellite communications and airport approach radars. Earlier attempts to achieve limited scan involved the use of parabolic lenses, zoning, and movable or dual-focus feeds. In the method described here, the main beam is scanned electronically by using a circular-arc phased array. The microwave lens is designed so that its back face satisfies the scanning condition. The beam is focused by shaping the front face of the lens to meet the required focusing condition and by varying the phase propagation of the lens. Two of the lenses studied were dielectric-loaded. A waveguide lens designed to scan in one dimension yielded experimental results that were good agreement with the theoretical predictions. Representative plots, and computer-generated farfield patterns of two topographically unique cases, are given.
Download or read book Basic Radar Analysis Second Edition written by Mervin C. Budge and published by Artech House. This book was released on 2020-04-30 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highly-anticipated second edition of an Artech House classic covers several key radar analysis areas: the radar range equation, detection theory, ambiguity functions, waveforms, antennas, active arrays, receivers and signal processors, CFAR and chaff analysis. Readers will be able to predict the detection performance of a radar system using the radar range equation, its various parameters, matched filter theory, and Swerling target models. The performance of various signal processors, single pulse, pulsed Doppler, LFM, NLFM, and BPSK, are discussed, taking into account factors including MTI processing, integration gain, weighting loss and straddling loss. The details of radar analysis are covered from a mathematical perspective, with in-depth breakdowns of radar performance in the presence of clutter. Readers will be able to determine the nose temperature of a multi-channel receiver as it is used in active arrays. With the addition of three new chapters on moving target detectors, inverse synthetic aperture radar (ISAR) and constant false alarm rate (CFAR) and new MATLAB codes, this expanded second edition will appeal to the novice as well as the experienced practitioner.
