Download or read book Dual band Beam Scanning Reflectarrays and Novel Wideband and Polarization Diversified Planar Antennas written by Shih-Hsun Hsu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The reflectarray antenna has been considered as a suitable candidate to replace the traditional parabolic reflectors because of its high-gain and low-profile features. Beam scanning capability and multi-band operation are the current trends of the reflectarray design. It is desired to implement these functionalities with simple and effective techniques. Narrow bandwidth is the main issue which restricts the applications of the microstrip antennas. New microstrip slot antennas and polarization diversified planar antennas are introduced as the solutions to the issue of narrow bandwidth in this dissertation. A dual-band beam scanning reflectarray has been developed. It is the first offset-fed reflectarray that has been ever practically developed to emulate a cylindrical/parabolic type of reflector. Unlike other beam scanning reflectarrays which integrate phase tuning devices into the reflectarray elements and control the reflection phase, the beam scanning capability of this reflectarray is provided by its feed array. This method significantly reduces the complexity of the design of the beam scanning reflectarray. A new dual-band reflectarray configuration is also developed to eliminate the possible top layer blocking effects in the dual-layer reflectarray configuration. Perforated patches loaded with slots on the ground plane and rectangular patches loaded with slots on the patches are adopted as the low and high frequency bands, respectively. It is guaranteed that no physical contact between any two elements will occur. The bandwidth of the conventional microstrip antenna is small. A new wideband circularly polarized microstrip slot antenna is introduced in this dissertation. Very wide 3-dB axial ratio bandwidth is observed for the proposed antenna. The antennas are assembled in triangularly arranged array with sequential rotation feed technique. Polarization polarity is an alternative solution to the narrow bandwidth. A reconfigurable circularly polarized microstrip antenna is proposed. The antenna has both right-hand and left-hand circular polarizations which are controlled by two piezoelectric transducers. In addition, a dual-band dual-linearly-polarized planar array is designed based on the concepts of polarization diversity and multi-band operation. The research presented in this dissertation suggests useful techniques for reflectarrays and novel antenna designs. The results should have many applications for the modern wireless communication and radar systems.

Download or read book Reflectarray Antennas written by Payam Nayeri and published by John Wiley & Sons. This book was released on 2018-02-23 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides engineers with a comprehensive review of the state-of-the-art in reflectarray antenna research and development. The authors describe, in detail, design procedures for a wide range of applications, including broadband, multi-band, multi-beam, contour-beam, beam-scanning, and conformal reflectarray antennas. They provide sufficient coverage of basic reflectarray theory to fully understand reflectarray antenna design and analysis such that the readers can pursue reflectarray research on their own. Throughout the book numerous illustrative design examples including numerical and experimental results are provided. Featuring in-depth theoretical analysis along with practical design examples, em style="mso-bidi-font-style: normal;"Reflectarray Antennas is an excellent text/reference for engineering graduate students, researchers, and engineers in the field of antennas. It belongs on the bookshelves of university libraries, research institutes, and industrial labs and research facilities.

Download or read book Reflectarray Antennas Analysis Design Fabrication and Measurement written by Jafar Shaker and published by Artech House. This book was released on 2013-11-01 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflectarray antennas refer to the class of radiating structures that are comprised of an array of radiating elements, re-radiating the energy that is impinged on them from one or more radiating feeds that are located in free space. The constituent radiators that build a reflectarray can be shaped to bring about some flexibility in the way that antenna operates such as multi band/polarization operation. The printed nature of these elements allow integration of active elements that can further enhance the functionality of the reflectarray. This allows for capabilities such as power amplification, adaptive beam shaping, and beam switching. This resource presents readers with design guidelines along with an ample amount of material on different types of reflectarrays and methods of analysis. This book begins with introductory material on reflectarray antennas and progresses to the presentation of state-of-the-art research in the field. A direct comparison with conventional reflector antennas is provided, focusing on conventional efficiency figures of reflectors. Moreover, this book offers remarks on the future direction of reflectarray research and also potential applications of the technology in face of the emergence of new fabrication techniques to accommodate both passive and active elements.

Download or read book Reflectarray Antennas written by John Huang and published by Wiley-IEEE Press. This book was released on 2007-11-09 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the configuration and principles of a reflectarray antenna, its advantages over other antennas, the history of its development, analysis techniques, practical design procedures, bandwidth issues and wideband techniques, as well as applications and recent developments. Both authors are well respected practitioners who have build these antennas and developed them for space flight.

Download or read book Handbook of Reflector Antennas and Feed Systems Volume I Theory and Design of Reflectors written by Satish K. Sharma and published by Artech House. This book was released on 2013-07-01 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly comprehensive and most up-to-date handbook available on modern reflector antennas and feed sources for diversified space and ground applications. There has never been such an all-encompassing reflector handbook in print, and no currently available title offers coverage of such recent research developments. The Handbook consists of three volumes. Volume I provides a unique combination of theoretical underpinnings with design considerations and techniques. The need for knowledge in reflector antennas has grown steadily over the last two decades due to increased use in space and ground applications, as well as their high gain and wide bandwidth capabilities at relatively low cost. This volume brings you to the leading edge of developments in the field related to numerical techniques, classical reflector geometries, adaptive reflector antennas, shaped reflectors, bifocal and bicollimated dual reflectors, advanced reflectors, and reflect arrays. A must-have reference for both practicing engineers as well as academic researchers.

Download or read book Advanced Design Methodologies and Novel Applications of Reflectarray Antennas written by Payam Nayeri and published by . This book was released on 2012 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflectarray antennas combine the numerous advantages of printed antenna arrays and reflector antennas and create a hybrid high-gain antenna with a low-profile, low-mass, and diversified radiation performance. Reflectarrays are now emerging as the new generation of high-gain antennas for long-distance communications. In this dissertation, some advanced concepts demonstrating novel features of reflectarray antennas are presented. * First, various approaches for radiation analysis of reflectarray antennas are described and implemented. Numerical results are then presented for a variety of systems and the advantages, limitations, and accuracy of these approaches are discussed and compared with each other. * A broadband technique by using sub-wavelength elements is proposed and prototypes are fabricated and tested. This technique enables the reflectarray to achieve a significant bandwidth improvement with no additional cost. * Infrared reflectarrays antennas are studied for possible applications in concentrating solar power systems. Material losses, an important design issue at infrared frequencies, are investigated and reflectarrays consisted of dielectric resonant elements are proposed with low-loss features at infrared. * Multi-beam reflectarray antennas are studied and it is demonstrated that by optimizing the phase of the elements, a desirable multi-beam performance can be achieved using a single-feed. Local and global phase-only optimization techniques have been implemented. Two Ka-band quad-beam prototypes with symmetric and asymmetric beams have been fabricated and tested. * Different approaches for beam-scanning with reflectarray antennas are also reviewed and it is shown that for moderately wide angle beam-scanning, utilizing a feed displacement technique is more suitable than an aperture phase tuning approach. A feed displacement beam-scanning design with novel aperture phase distribution is proposed for the reflectarray antenna, and is further optimized to improve the performance. A high-gain Ka-band prototype achieving 60 degrees scan range with side-lobe levels below 15 dB is demonstrated. * The feasibility of designing reflectarray antennas on conformal surfaces is also studied numerically. A generalized analysis approach is presented and the radiation performance of reflectarray antennas on singly-curved conformal cylindrical platforms are studied and compared with their planar counterpart. It is revealed that conformal reflectarray antennas are a suitable choice for a high-gain antenna where curved platforms are required. In summary, different challenges in reflectarray analysis and design are addressed in this dissertation. On the element design challenges, bandwidth improvement and infrared operation of reflectarray antennas have been studied. On the system level challenges, multi-beam designs, beam-scanning performance, and conformal platforms have been investigated. Several prototypes have been fabricated and tested, demonstrating the novel features and potential applications of reflectarray antennas.

Download or read book Broadband Approaches and Beam scanning Techniques for Reflectarray Antenna written by Yilin Mao and published by . This book was released on 2014 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflectarray antennas combine the numerous advantages of reflector antennas and phased array antennas and create a hybrid high-gain antenna with a low-profile, low-mass, easy-fabrication, and diversified radiation performance. However, it still has some inherent drawbacks, such as limited bandwidth and scanning range, which are targeted in this dissertation.At first, the array theory approach for radiation analysis of reflectarray antennas is described and implemented. Numerical results are then presented and compared with reference results to confirm its reliability. As the most critical influential factor to the reflectarray bandwidth, the element bandwidth was studied at first, and the effects of element shape and substrate thickness were investigated. Then, a comprehensive study was performed to investigate the bandwidth performance of reflectarrays on the system level. The effect of aperture size, element bandwidth and phase synthesis method was discussed in sequence. Particularly, a novel phase synthesis approach was proposed, which enables reflectarray to achieve a significant bandwidth improvement even with elements of narrow bandwidth. Prototypes are fabricated and tested to validate the idea. Since the reflectarray antenna is a hybrid product of reflector and phased array antennas, its main beam could be steered by either rotating its feed or reconfiguring its element phases. The former way was explored at first. An improved phase design was proposed for reflectarrays mimicing parabolic-cylindrical reflectors to expand its scanning range. The published achievements of reconfigurable reflectarrays design are reviewed and it is found that currently efficiency is a big problem. A 1-bit 10×10 reconfigurable reflectarray using PIN diode was designed, fabricated and measured to explore the energy loss, and experimental results showed that 14% efficiency could be reached. In summary, some improved designs regarding bandwidth and scanning performance for reflectarrays are proposed in this dissertation. Various factors affecting reflectarray bandwidth are investigated, which shall provide some guidelines regarding bandwidth improvement. On the other hand, two designs are presented to explore the beam scanning characteristic of reflectarray antenna, by mechanical and electrical ways respectively. Several prototypes have been fabricated and measured, demonstrating the novel features and potential applications of reflectarray antennas.

Download or read book Reconfigurable Dual band and Wide band Spatially fed Array Antennas written by Min Yin Xu and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the designs of two reconfigurable spatially-fed antenna arrays with the potential to be applied in satellite communications. The first design is a dual-band circularly-polarized reflectarray antenna (RA). The RA unit cell is comprised of two concentric microstrip rings, one for each operation frequency. Each ring is loaded with four varactor diodes to achieve CP response through concurrent manipulation of both vertically and horizontally polarized waves. Experimental characterization of the unit cell showed sufficient phase-shifting capability covering the two frequency bands of interest. The second design is a reconfigurable Huygens' metasurfaces (HMS) that have the potential of obtaining wideband tunable responses by incorporating tunable elements into the surface. This is possible since the HMS implements both the electric and magnetic responses. An equivalent circuit model for the HMS is presented, followed by a low-complexity reconfigurable HMS unit cell design.

Download or read book Dual band Reflectarrays Using Microstrip Ring Elements and Their Applications with Various Feeding Arrangements written by Chul Min Han and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years there has been a growing demand for reduced mass, small launch volume, and, at the same time, high-gain large-aperture antenna systems in modernspace-borne applications. This dissertation introduces new techniques for dual-band reflectarray antennas to meet these requirements. A series of developments is presented to show the dual-band capability of the reflectarray. A novel microstrip ring structure has been developed to achieve circular polarization (CP). A C/Ka dual-band front-fed reflectarray antenna has been designed to demonstrate the dual-band circular polarized operation. The proposed ring structure provides many advantages of compact size, more freedom in the selection of element spacing, less blockage between circuit layers, and broader CP bandwidth as compared to the patches. An X/Ka dual-band offset-fed reflectarray is made of thin membranes, with theirthickness equal to 0.0508 mm in both layers. Several degrading effects of thin substratesare discussed. To overcome these problems, a new configuration is developed by inserting empty spaces of the proper thickness below both the X and Ka band membranes. More than 50 % efficiencies are achieved at both frequency ranges, and the proposed scheme is expected to be a good candidate to meet the demand for future inflatable antenna systems. An X/Ka dual-band microstrip reflectarray with circular polarization has also been constructed using thin membranes and a Cassegrain offset-fed configuration. It is believed that this is the first Cassegrain reflectarray ever developed. This antenna has a 0.75-meter-diameter aperture and uses a metallic sub-reflector and angular-rotated annular ring elements. It achieved a measured 3 dB gain bandwidth of 700 MHz at Xbandand 1.5 GHz at Ka-band, as well as a CP bandwidth (3 dB axial ratio) of more than700 MHz at X-band and more than 2 GHz at Ka-band. The measured peak efficienciesare 49.8 % at X-band and 48. 2 % at Ka-band. In summary, this dissertation presents a series of new research developments to support the dual-band operation of the reflectarray antenna. The results of this work are currently being implemented onto a 3-meter reflectarray with inflatable structures at theJet Propulsion Laboratory and are planned for other applications such as an 8-meter inflatable reflectarray in the near future.

Download or read book High power Phased array Antennas Exploiting Polarization Rotation and Sub wavelength Periodic Structures written by Zongtang Zhang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phased-array antennas have been deployed to address some of the needs of various applications ranging from satellite, mobile, and airborne communications to radar and electronic warfare systems. However, their extreme cost and complexity have limited their application only to the most expensive pieces of military hardware. Therefore, new ideas for developing affordable, wideband, high-power-capable phased arrays are needed to enable the widespread use of this technology in future tactical systems. To address this need, this dissertation investigates four different designs of affordable, high-power-capable, passive phased-array antennas. The first design presented a dual-band polarization-rotating reflectarray. The proposed dual-band reflectarray is capable of independent beam control at each band. The second design introduced a high-power-capable, ultra-wideband phase shifter that exploits the concept of polarization rotation to achieve 1-bit electronic phase shifting capability while handling extremely high power levels. This high-power phase shifter can be used either in a high-power transmitarray or in a high-power, direct-fed, passive phased-array architecture. Two different Risley-prism-based, mechanically beam-steerable antennas were presented in Chapter 4 and 5. It can provide good 2D beam steering performance in the upper space with relatively simple structures. These two designs are expected to be useful in designing affordable, beam-steerable antennas in which scanning speed can be traded off to reduce system complexity.

Download or read book Analysis and Design of Transmitarray Antennas written by Ahmed H. Abdelrahman and published by Morgan & Claypool Publishers. This book was released on 2017-01-18 with total page 177 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 Advances in Array Optimization written by Ertugrul Aksoy and published by BoD – Books on Demand. This book was released on 2020-03-04 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need to develop technology and communication necessitates the design of flexible and high-capacity radiating systems in today's communication infrastructure. In this context, antenna arrays are the ideal solution and have been one of the priority research subjects of the science community dealing with electromagnetics from past to present. Optimization of an array may be performed in various ways such as the optimization of excitation, reflector structure, feed network, etc. depending on the array structure. This book is a collection of seven research studies focused on the optimization of array structures in classical phased array or time modulation, including radiator, reflector, feed network, and radiating element optimizations.

Download or read book Space Antenna Handbook written by William A. Imbriale and published by John Wiley & Sons. This book was released on 2012-06-25 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses a broad range of topics on antennas for space applications. First, it introduces the fundamental methodologies of space antenna design, modelling and analysis as well as the state-of-the-art and anticipated future technological developments. Each of the topics discussed are specialized and contextualized to the space sector. Furthermore, case studies are also provided to demonstrate the design and implementation of antennas in actual applications. Second, the authors present a detailed review of antenna designs for some popular applications such as satellite communications, space-borne synthetic aperture radar (SAR), Global Navigation Satellite Systems (GNSS) receivers, science instruments, radio astronomy, small satellites, and deep-space applications. Finally it presents the reader with a comprehensive path from space antenna development basics to specific individual applications. Key Features: Presents a detailed review of antenna designs for applications such as satellite communications, space-borne SAR, GNSS receivers, science instruments, small satellites, radio astronomy, deep-space applications Addresses the space antenna development from different angles, including electromagnetic, thermal and mechanical design strategies required for space qualification Includes numerous case studies to demonstrate how to design and implement antennas in practical scenarios Offers both an introduction for students in the field and an in-depth reference for antenna engineers who develop space antennas This book serves as an excellent reference for researchers, professionals and graduate students in the fields of antennas and propagation, electromagnetics, RF/microwave/millimetrewave systems, satellite communications, radars, satellite remote sensing, satellite navigation and spacecraft system engineering, It also aids engineers technical managers and professionals working on antenna and RF designs. Marketing and business people in satellites, wireless, and electronics area who want to acquire a basic understanding of the technology will also find this book of interest.

Download or read book Information Metamaterials written by Tie Jun Cui and published by Cambridge University Press. This book was released on 2021-02-18 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metamaterials have attracted enormous interests from both physics and engineering communities in the past 20 years, owing to their powerful ability in manipulating electromagnetic waves. However, the functionalities of traditional metamaterials are fixed at the time of fabrication. To control the EM waves dynamically, active components are introduced to the meta-atoms, yielding active metamaterials. Recently, a special kind of active metamaterials, digital coding and programmable metamaterials, are proposed, which can achieve dynamically controllable functionalities using field programmable gate array (FPGA). Most importantly, the digital coding representations of metamaterials set up a bridge between the digital world and physical world, and allow metamaterials to process digital information directly, leading to information metamaterials. In this Element, we review the evolution of information metamaterials, mainly focusing on their basic concepts, design principles, fabrication techniques, experimental measurement and potential applications. Future developments of information metamaterials are also envisioned.

Download or read book Circularly Polarized Antennas written by Steven Shichang Gao and published by John Wiley & Sons. This book was released on 2014-02-03 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Advanced designs such as small-size CP antennas, broadband, wideband and ultra-wideband CP antennas are also discussed, as well as multi-band CP antennas and dual CP antennas. The design and analysis of different types of CP array antennas such as broadband CP patch arrays, dual-band CP arrays, CP printed slot arrays, single-band and multi-band CP reflectarrays, high-gain CP waveguide slot antennas, CP dielectric resonator antenna arrays, CP active arrays, millimetre-waveband CP arrays in LTCC, and CP arrays with electronically beam-switching or beam-steering capabilities are described in detail. Case studies are provided to illustrate the design and implementation of CP antennas in practical scenarios such as dual-band Global Navigation Satellite Systems (GNSS) receivers, satellite communication mobile terminals at the S-band, Radio Frequency Identification (RFID) readers at 2.4 GHz, and Ka-band high-speed satellite communication applications. It also includes the detailed designs for a wideband Logarithmic spiral antenna that can operate from 3.4-7.7 GHz. In addition, the book offers a detailed review of the recent developments of different types of CP antennas and arrays. Presents comprehensive discussions of design techniques for different types of CP antennas: small-size CP antennas, broadband CP antennas, multi-band CP antennas and CP arrays. Covers a wide range of antenna technologies such as microstrip antennas, helix, quadrifilar helix antenna, printed quadrifilar helix antenna, dielectric resonator antennas, printed slots, spiral antennas, monopoles, waveguide slot arrays, reflectarrays, active arrays, millimetre-wave arrays in LTCC, electronically beam-switching arrays and electronically beam-steerable arrays. Reviews recent developments in different types of CP antennas and arrays, reported by industries, researchers and academics worldwide. Includes numerous case studies to demonstrate how to design and implement different CP antennas in practical scenarios. Provides both an introduction for students in the field and an in-depth reference for antenna/RF engineers who work on the development of CP antennas. Circularly Polarized Antennas will be an invaluable guide for researchers in R&D organizations; system engineers (antenna, telecom, space and satellite); postgraduates studying the subjects of antenna and propagation, electromagnetics, RF/microwave/millimetre-wave systems, satellite communications and so on; technical managers and professionals in the areas of antennas and propagation.

Download or read book Handbook of Reflector Antennas and Feed Systems Volume III Applications of Reflectors written by Sudhakar Rao and published by Artech House. This book was released on 2013-06-01 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly comprehensive and most up-to-date handbook available on modern reflector antennas and feed sources for diversified space and ground applications. There has never been such an all-encompassing reflector handbook in print, and no currently available title offers coverage of such recent research developments. The Handbook consists of three volumes. Volume III focuses on the range of reflector antenna applications, including space, terrestrial, and radar. The intent of this book volume is to provide practical applications and design information on reflector antennas used for several communications systems. This book covers recent developments of reflector antennas used for satellite communications, terrestrial communications, and remote sensing applications. New subjects are introduced for the first time, including satellite antennas, Terahertz antennas, PIM, multipaction, corona, deployable mesh reflector antennas, and mechanical aspects of reflector antennas. In addition, this book contains a separate topic on integrated feed assembly for reflector antennas covering analysis, design, fabrication, and test.

Download or read book Air and Spaceborne Radar Systems written by Philippe Lacomme and published by William Andrew. This book was released on 2001 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intended for actual users of radar, the book focuses on the history, main principles, functions, modes, properties and specific nature of modern airborne radar. It examines radar's role within the system when carrying out its assigned missions, showing the possibilities of radar, it's limitations and a discussion of how radar may evolve in the future.