Download or read book Non foster Circuit Design and Stability Analysis for Wideband Antenna Applications written by Aseim M. N. Elfrgani and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, there has been a great interest in wide-band small antennas for wireless communication in both ground and airborne applications. Electrically small antennas; however, are narrow bandwidth since they exhibit high a quality factor (Q). Therefore, matching networks are required to improve their input impedance and radiation characteristics. Unfortunately, due to gain-bandwidth restrictions, wideband matching cannot be achieved using passive networks unless a high order matching network is used. Fortunately, the so-called non-Foster circuits (NFCs) employ active networks to bypass the well-known gain-bandwidth restrictions derived by Bode-Fano. Although NFCs can be very useful in numerous microwave and antenna applications, they are difficult to design because they are potentially instable. Consequently, an accurate and efficient systematic stability assessment is necessary during the design process to predict any undesired behavior. In this dissertation, the design, stability, and measurement of two non-Foster matching networks for two different small monopole antennas, a non-Foster circuit embedded within half loop antenna, a combination of Foster and non-Foster matching network for small monopole antenna are presented. A third circuit; namely, a non-Foster coupling network for a two-element monopole array is also presented for phase enhancement applications. It all examples, the NFCs substantially improve the antenna's performance over a wide frequency band.

Download or read book Antennas with Non Foster Matching Networks written by James T. Aberle and published by Morgan & Claypool Publishers. This book was released on 2007-12-01 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most antenna engineers are likely to believe that antennas are one technology that is more or less impervious to the rapidly advancing semiconductor industry. However, as demonstrated in this lecture, there is a way to incorporate active components into an antenna and transform it into a new kind of radiating structure that can take advantage of the latest advances in analog circuit design. The approach for making this transformation is to make use of non-Foster circuit elements in the matching network of the antenna. By doing so, we are no longer constrained by the laws of physics that apply to passive antennas. However, we must now design and construct very touchy active circuits. This new antenna technology is now in its infancy. The contributions of this lecture are (1) to summarize the current state-of-the-art in this subject, and (2) to introduce some new theoretical and practical tools for helping us to continue the advancement of this technology.

Download or read book Ultra Wideband Antennas written by Giselle M. Galvan-Tejada and published by CRC Press. This book was released on 2017-12-19 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book: Discusses the developed theory for UWB antennas in frequency and time domains Delivers a brief exposition of numerical methods for electromagnetics oriented to antennas Describes solid-planar equivalence, which allows flat structures to be implemented instead of volumetric antennas Examines the impedance matching, phase linearity, and radiation patterns as design objectives for omnidirectional and directional antennas Addresses the time domain signal analysis for UWB antennas, from which the distortion phenomenon can be modeled Includes illustrative examples, design equations, CST MICROWAVE STUDIO® simulations, and MATLAB® plot generations Compares the performance of different UWB antennas, supplying useful insight into particular tendencies and unresolved problems Ultra Wideband Antennas: Design, Methodologies, and Performance provides a valuable reference for the scientific community, as UWB antennas have a variety of applications in body area networks, radar, imaging, spectrum monitoring, electronic warfare, wireless sensor networks, and more.

Download or read book Non foster Antenna Matching Networks Using Reflection mode Negative group delay Networks written by Alhasan Ali Moftah Almahroug and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-Foster networks provide a possible route for broad band matching of antennas. The major challenges when designing non-Foster elements using conventional Negative Impedance Converters (NICs) arise from the stability concerns, due to the existence of the feedback in the circuitry and the generation of negative impedance. Therefore, investigation of alternative means for designing non-Foster elements which are more stable is imperative. This thesis presents a new perspective in designing non-Foster reactive elements based on negative group delay (NGD) networks. A novel reflection-mode NGD network is designed, fabricated and tested. Subsequently, a novel approach which contains a negative resistance amplifier and a Lange coupler is introduced to compensate the losses of the NGD networks. A simple equivalent circuit model (-L, -C) of the proposed NGD-based non-Foster network is presented and can be used to deploy the non-Foster network in an antenna matching network. Theoretical analysis based on Nyquist approach shows that stability can be achieved but practical implementation issues can cause stability problems. . Finally, approximate calculations of the non-linearity and noise performance addressing the operational limitations of the proposed circuit in transmit and receive applications have been introduced.

Download or read book Ultrawideband Antennas written by Daniel Valderas and published by World Scientific. This book was released on 2011 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrawideband (UWB) technology, positioned as the cutting edge of research and development, paves the way to meet the emerging demands set by broadband wireless applications, such as high-speed data transmission, medical imaging, short-range radars, electromagnetic testing, etc. This breathtaking resource builds upon the basics of UWB technology to provide a complete compilation of figures of merit along with a vital state-of-the-art of the different antenna alternatives that are to be employed according to the specific application. Without excessive recourse to mathematics, this volume emphasizes on the UWB antenna design and equips readers with practical prediction techniques based on simple formulas and models. The big picture of UWB antenna technology would not be complete without addressing its applications, and this will serve to provide consultants with key clues for slot market searching. Containing over 150 supporting illustrations and figures, this comprehensive overview of UWB technology, antenna design and applications is a vital source of information and reference for R&D organizations, researchers, practitioners, consultants, RF professionals and communication engineers.

Download or read book Design Methodology for Wideband Electrically Small Antennas ESA Based on the Theory of Characteristic Modes CM written by Khaled A. Obeidat and published by . This book was released on 2010 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Emerging broadband applications with market pressures for miniaturized communication devices have encouraged the use of electrically small antennas (ESA) and highly integrated RF circuitry for high volume low cost mobile devices. This research work focuses on developing a novel scheme to design wideband electrical small antennas that incorporates active and passive loading as well as passive matching networks. Several antennas designed using the proposed design technique and built and measured to assess their performance and to validate the design methodology. Previously, the theory of Characteristic Modes (CM) has been used mostly for antennas analysis. However; in this chapter a design procedure is proposed for designing wide band (both the input impedance bandwidth and the far field pattern bandwidth) electrically small to mid size antennas using the CM in conjunction with the theory of matching networks developed by Carlin. In order to increase the antenna gain, the antenna input impedance mismatch loss needs to be minimized by carefully exciting the antenna either at one port or at multiple ports and/or load the antenna at different ports along the antenna body such that the Q factor in the desired frequency range is suitable for wideband matching network design. The excitation (feeding structure), the loading of the antenna and/or even small modifications to the antenna structure can be modeled and understood by studying the eigenvalues and their corresponding eigencurrents obtained from the CM of the antenna structure. A brief discussion of the theory of Characteristic Modes (CM) will be presented and reviewed before the proposed design scheme is introduced. The design method will be used to demonstrate CM applications to widen the frequency bandwidth of the input impedance of an electrically small Vee shape Antenna and to obtain vertically polarized Omni-directional patterns for such antenna over a wide bandwidth. A loading technique based on the CM to either design frequency reconfigurable antennas or broaden their bandwidth by Non-Foster loading will also be discussed as part of the design methodology. In the Appendix, a brief discussion of the fundamental limits of electrical small antennas is presented and then followed by a discussion of the fundamental limits of the impedance bandwidth of the ESA when a passive matching network is used. Matching network implemented using Non-Foster matching is also discussed in the appendix.

Download or read book Non Foster Circuits for High Performance Antennas written by Minu Mariam Jacob and published by . This book was released on 2016 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for miniaturized, broadband communication systems has created a need for electrically small, broadband antennas. However, all passive electrically small antennas have a fundamental gain-bandwidth limitation related to their electrical size, as first described by Wheeler and Chu. This limitation can be overcome using active non-Foster circuits (negative inductors and/or negative capacitors), which can deliver a broadband input match with active matching techniques, or can help reduce phase dispersion using negative delay effects. This thesis will illustrate the advantages of non-Foster circuits in obtaining broadband small antennas, in addition to examining their practical limitations due to noise in receive applications, and nonlinearity in transmit applications.

Download or read book Novel Method to Control Antenna Currents Based on Theory of Characteristic Modes written by Ezdeen Ahmed Elghannai and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Characteristic Mode Theory is one of the very few numerical methods that provide a great deal of physical insight because it allows us to determine the natural modes of the radiating structure. The key feature of these modes is that the total induced antenna current, input impedance/admittance and radiation pattern can be expressed as a linear weighted combination of individual modes. Using this decomposition method, it is possible to study the behavior of the individual modes, understand them and therefore control the antennas behavior; in other words, control the currents induced on the antenna structure. This dissertation advances the topic of antenna design by carefully controlling the antenna currents over the desired frequency band to achieve the desired performance specifications for a set of constraints. Here, a systematic method based on the Theory of Characteristic Modes (CM) and lumped reactive loading to achieve the goal of current control is developed. The lumped reactive loads are determined based on the desired behavior of the antenna currents. This technique can also be used to impedance match the antenna to the source/generator connected to it. The technique is much more general than the traditional impedance matching. Generally, the reactive loads that properly control the currents exhibit a combination of Foster and non-Foster behavior. The former can be implemented with lumped passive reactive components, while the latter can be implemented with lumped non-Foster circuits (NFC). The concept of current control is applied to design antennas with a wide band (impedance/pattern) behavior using reactive loads. We successfully applied this novel technique to design multi band and wide band antennas for wireless applications. The technique was developed to match the antenna to resistive and/or complex source impedance and control the radiation pattern at these frequency bands, considering size and volume constraints. A wide band patch antenna was achieved using the developed technique. In addition, the technique was applied to multi band wireless Universal Serial Bus (USB) dongle antenna that serves for WLAN IEEE 802.11 a/b/g/n band applications and Radio Frequency Identification (RFID) tag antenna for 915MHz band applications with superior performance compared to previous published results. This dissertation also discusses the total Q of an antenna from the CM standpoint. A new expression as well as additional physical information about each mode's individual contribution to the total antenna Q are provided. Finally, the theory is used to an analyze the antenna in both radiation and/or scattering modes. In the antenna scattering mode, the field scattered by an antenna contains a component that is the short circuit scattered field, and a second component that is proportional to the radiation field. In this dissertation, an analytical study of this phenomena from the CM standpoint is performed aiming to shed some light on antenna scattering phenomenon where additional physical insight is obtained and thus used to reach desire results.

Download or read book Design and Applications of Active Integrated Antennas written by Mohammad S. Sharawi and published by Artech House. This book was released on 2018-05-31 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive new resource guides professionals in the latest methods used when designing active integrated antennas (AIA) for wireless communication devices for various standards. This book provides complete design procedures for the various elements of such active integrated antennas such as the matching network, the amplifier/active element as well as the antenna. This book offers insight into how active integration and co-design between the active components (amplifier, oscillator, mixer, diodes) and the antenna can provide better power transfer, higher gains, increased efficiencies, switched beam patterns and smaller design footprints. It introduces the co-design approach of active integrated antennas and its superior performance over conventional methods. Complete design examples are given of active integrated antenna systems for narrow and wideband applications as well as for multiple-input-multiple-output (MIMO) systems. Readers find the latest design methods for narrow and broadband RF matching networks. This book provides a complete listing of performance metrics for active integrated antennas. The book serves as a complete reference and design guide in the area of AIA.

Download or read book Microwave Circuit Design Using Linear and Nonlinear Techniques written by George D. Vendelin and published by John Wiley & Sons. This book was released on 2005-10-03 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate handbook on microwave circuit design with CAD. Full of tips and insights from seasoned industry veterans, Microwave Circuit Design offers practical, proven advice on improving the design quality of microwave passive and active circuits-while cutting costs and time. Covering all levels of microwave circuit design from the elementary to the very advanced, the book systematically presents computer-aided methods for linear and nonlinear designs used in the design and manufacture of microwave amplifiers, oscillators, and mixers. Using the newest CAD tools, the book shows how to design transistor and diode circuits, and also details CAD's usefulness in microwave integrated circuit (MIC) and monolithic microwave integrated circuit (MMIC) technology. Applications of nonlinear SPICE programs, now available for microwave CAD, are described. State-of-the-art coverage includes microwave transistors (HEMTs, MODFETs, MESFETs, HBTs, and more), high-power amplifier design, oscillator design including feedback topologies, phase noise and examples, and more. The techniques presented are illustrated with several MMIC designs, including a wideband amplifier, a low-noise amplifier, and an MMIC mixer. This unique, one-stop handbook also features a major case study of an actual anticollision radar transceiver, which is compared in detail against CAD predictions; examples of actual circuit designs with photographs of completed circuits; and tables of design formulae.

Download or read book Distributed Power Amplifiers for RF and Microwave Communications written by Narendra Kumar and published by Artech House. This book was released on 2015-06-01 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new resource presents readers with all relevant information and comprehensive design methodology of wideband amplifiers. This book specifically focuses on distributed amplifiers and their main components, and presents numerous RF and microwave applications including well-known historical and recent architectures, theoretical approaches, circuit simulation, and practical implementation techniques. A great resource for practicing designers and engineers, this book contains numerous well-known and novel practical circuits, architectures, and theoretical approaches with detailed description of their operational principles.

Download or read book Stability Analysis of Nonlinear Microwave Circuits written by Almudena Suárez and published by Artech House. This book was released on 2003 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation "Stability Analysis of Nonlinear Microwave Circuits is essential reading for microwave designers working with circuits based on solid state devices, diodes, and transistors, engineers designing radio-frequency circuits, and professionals regularly involved in any area requiring a functional knowledge of nonlinear oscillations and stability concepts. It provides an in-depth look at the very complex and often unforeseen behavior of nonlinear circuits. The book includes detailed coverage of power amplifiers, voltage-controlled oscillators, frequency dividers, frequency multipliers, self-oscillating mixers, and phased-locked loops."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved

Download or read book Microstrip Patch Antennas written by Kai Fong Lee and published by World Scientific. This book was released on 2011 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstrip patch antennas have become the favorite of antenna designers because of its versatility and advantages of planar profile, ease of fabrication, compatibility with integrated circuit technology, and conformability with a shaped surface. As there is currently an urgent need for graduate students and practicing engineers to gain an in-depth understanding of this subject, this book was written with this purpose in mind. The authors are IEEE Fellows who have made significant contributions to their fields of expertise. Professor K F Lee was the recipient of the 2009 John Kraus Antenna Award of the IEEE Antennas and Propagation Society.

Download or read book Foundations of Oscillator Circuit Design written by Guillermo Gonzalez and published by Artech House Publishers. This book was released on 2007 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oscillators are an important component in today's RF and microwave systems, and practitioners in the field need to know how to design oscillators for stability and top performance. Offering engineers broader coverage than other oscillator design books on the market, this comprehensive resource considers the complete frequency range, from low-frequency audio oscillators to more complex oscillators found at the RF and microwave frequencies. Packed with over 1,200 equations, the book gives professionals a thorough understanding of the principles and practice of oscillator circuit design and emphasizes the use of time-saving CAD (computer aided design) simulation techniques. From the theory and characteristics of oscillators, to the design of a wide variety of oscillators (including tuned-circuit, crystal, negative-resistance, and relaxation oscillators), this unique book is a one-stop reference practitioners can turn to again and again when working on their challenging projects in this field.

Download or read book Small Antennas Miniaturization Techniques Applications written by John Volakis and published by McGraw Hill Professional. This book was released on 2009-12-22 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Next-generation small antenna design techniques This authoritative text provides the most up-to-date methods on the theory and design of small antennas, including an extensive survey of small antenna literature published over the past several years. Written by experts at the forefront of antenna research, Small Antennas: Miniaturization Techniques & Applications begins with a detailed presentation of small antenna theory--narrowband and wideband--and progresses to small antenna design methods, such as materials and shaping approaches for multiband and wideband antennas. Generic miniaturization techniques are presented for narrowband, multiband, and wideband antennas. Two chapters devoted to metamaterials antennas and methods to achieve optimal small antennas, as well as a chapter on RFID technologies and related antennas, are included in this comprehensive volume. Coverage includes: Small antenna theory and optimal parameters Theory and limits of wideband electrically small antennas Extensive literature survey of small antenna designs Practical antenna miniaturization approaches Conformal wideband antennas based on spirals Negative refractive index (NRI) metamaterial and electromagnetic band gap (EBG) based antennas Small antennas based on magnetic photonic and degenerate band edge crystals Impedance matching for small antennas using passive and active circuits RFID antennas and technology

Download or read book Design of Ultra Wideband Power Transfer Networks written by Binboga Siddik Yarman and published by John Wiley & Sons. This book was released on 2010-02-22 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combining analytic theory and modern computer-aided design techniques this volume will enable you to understand and design power transfer networks and amplifiers in next generation radio frequency (RF) and microwave communication systems. A comprehensive theory of circuits constructed with lumped and distributed elements is covered, as are electromagnetic field theory, filter theory, and broadband matching. Along with detailed roadmaps and accessible algorithms, this book provides up-to-date, practical design examples including: filters built with microstrip lines in C and X bands; various antenna matching networks over HF and microwave frequencies; channel equalizers with arbitary gain shapes; matching networks for ultrasonic transducers; ultra wideband microwave amplifiers constructed with lumped and distributed elements. A companion website details all Real Frequency Techniques (including line segment and computational techniques) with design tools developed on MatLab. Essential reading for all RF and circuit design engineers, this is also a great reference text for other electrical engineers and researchers working on the development of communications applications at wideband frequencies. This book is also beneficial to advanced electrical and communications engineering students taking courses in RF and microwave communications technology. www.wiley.com/go/yarman_wideband

Download or read book Microwave Filters Impedance matching Networks and Coupling Structures written by George L. Matthaei and published by . This book was released on 1964 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt: