Download or read book Two tier Push pull Radio Frequency Power Amplifier for Wideband Code Division Multiple Access Basestation written by Dhruvit H. Patel and published by . This book was released on 2005 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dual band Power Amplifier for Wireless Communication Base Stations written by Xin Fu and published by . This book was released on 2012 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: In wireless communication systems, multiple standards have been implemented to meet the past and present demands of different applications. This proliferation of wireless standards, operating over multiple frequency bands, has increased the demand for radio frequency (RF) components, and consequently power amplifiers (PA) to operate over multiple frequency bands. In this research work, a systematic approach for the synthesis of a novel dual-band matching network is proposed and applied for effective design of PA capable of maintaining high power efficiency at two arbitrary widely spaced frequencies. The proposed dual-band matching network incorporates two different stages. The first one aims at transforming the targeted two complex impedances, at the two operating frequencies, to a real one. The second stage is a dual-band filter that ensures the matching of the former real impedance to the termination impedance to 50 Ohm. Furthermore, an additional transmission line is incorporated between the two previously mentioned stages to adjust the impedances at the second and third harmonics without altering the impedances seen at the fundamental frequencies. Although simple, the harmonic termination control is very effective in enhancing the efficiency of RF transistors, especially when exploiting the Class J design space. The proposed dual-band matching network synthesis methodology was applied to design a dual-band power amplifier using a packaged 45 W gallium nitride (GaN) transistor. The power amplifier prototype maintained a peak power efficiency of about 68% at the two operating frequencies, namely 800 MHz and 1.9 GHz. In addition, a Volterra based digital predistortion technique has been successfully applied to linearize the PA response around the two operating frequencies. In fact, when driven with multi-carrier wideband code division multiple access (WCDMA) and long term evolution (LTE) signals, the linearized amplifier maintained an adjacent channel power ratio (ACPR) of about 50 dBc and 46 dBc, respectively.

Download or read book Partitioning Design Approach for the Reliable Design of Highly Efficient RF Power Amplifiers written by Roshanak Lehna and published by kassel university press GmbH. This book was released on 2017-11-13 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern wireless communication systems require modulated signals with wide modulation bandwidth. This, in turns, requires signals with very high dynamic range and peak-to-average power ratio (PAPR). This means that the amplifier in the base-station has to work at a power back-off as large as the dynamic range of the signal, so that the amplifier has a high linearity in this region. For the standard single-stage amplifiers, this large power back-off reduces the efficiency dramatically. In this work, a three-way Doherty power amplifier (DPA) aiming at high power efficiency within a dynamic range of 9.5 dB, is designed and fabricated using partitioning design approach. The partitioning design approach decomposes a complex design task into small-sized, well-controllable, and verifiable subcircuits. This advanced straight forward method has shown very promising results. Using this design approach, a three-way DPA has been designed to demonstrate the advantages of this reliable design technique as well. Based on the design of a single-stage power amplifier and proposing a novel output power combiner, a 6 W three-way DPA has been designed which allows the mandatory load modulation principle in three-way DPA structures to be realized with simpler elements, whereas the design of a standard Doherty combiner would have been very challenging and not practical due to the extremely small value of its characteristic line impedance. The proposed combiner is calculated for a three-way DPA with 2-mm AlGaN/GaN-HEMTs. The simulation result shows a very good load modulation for the amplifier, which confirms the theoretical expectation for a three-way DPA. The efficiency of the designed 6 W three-way DPA at large back-off shows very promising values compared to recently reported amplifiers. The measured IMD3 products confirm the good linearity of the amplifier as well. Accordingly, the proposed power combiner and the design strategy are recommended to be used as the preferred option for designing three-way DPA structures with very high output power.

Download or read book Modeling and Design Techniques for RF Power Amplifiers written by Arvind Raghavan and published by John Wiley & Sons. This book was released on 2008-01-09 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Achieve higher levels of performance, integration, compactness, and cost-effectiveness in the design and modeling of radio-frequency (RF) power amplifiers RF power amplifiers are important components of any wireless transmitter, but are often the limiting factors in achieving better performance and lower cost in a wireless communication system—presenting the RF IC design community with many challenges. The next-generation technological advances presented in this book are the result of cutting-edge research in the area of large-signal device modeling and RF power amplifier design at the Georgia Institute of Technology, and have the potential to significantly address issues of performance and cost-effectiveness in this area. Richly complemented with hundreds of figures and equations, Modeling and Design Techniques for RF Power Amplifiers introduces and explores the most important topics related to RF power amplifier design under one concise cover. With a focus on efficiency enhancement techniques and the latest advances in the field, coverage includes: Device modeling for CAD Empirical modeling of bipolar devices Scalable modeling of RF MOSFETs Power amplifier IC design Power amplifier design in silicon Efficiency enhancement of RF power amplifiers The description of state-of-the-art techniques makes this book a valuable and handy reference for practicing engineers and researchers, while the breadth of coverage makes it an ideal text for graduate- and advanced undergraduate-level courses in the area of RF power amplifier design and modeling.

Download or read book Push pull Based High Efficiency and High Power Broadband Power Amplifiers for Wireless Base Stations written by Ayman Jundi and published by . This book was released on 2019 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monthly data throughput by 2021 is forecasted to be ten times that of December 2015. As a result of the on going dramatic increase in demand, service providers are assigned new frequency bands to accommodate more channels to carry more data. However, the usable part of the spectrum is a limited resource so modern communication signals were designed to be more spectrally efficient to send more bits over the same channel bandwidth. However, these spectrally efficient signals have high PAPR. The immediate reaction to these changes was to add additional RF front-end branches to accommodate the new frequency bands. Initially, the PAs used at the time were not optimized for back-off efficiency and where operating at low efficiency which caused significant increase in heat generation for the same average power produced which in turn increased cooling costs and reduced the life time of the PA. After the introduction of back-off efficiency enhancement techniques the PAs became more efficient however they were limited in bandwidth which is typically 10-15%. This work focuses on reducing the redundancy of power amplifiers in communication base stations while maintaining high back-off efficiency. After exploring the literature to understand the limitations of current implementations, it was found that the push-pull topology is often used at low frequency in broadband high power PAs. In the absence of a complimentary transistor pairs the push-pull implantation requires the use of balanced to unbalanced (balun) transformers. Various balun implantations were hence investigated to identify the most suitable option for broadband planar implementation. As a result, a methodology was proposed to co-design the balun and the matching network in order to have better control over the harmonic impedance. An 85 W push-pull PA was then designed based on the proposed methodology with a multi-octave bandwidth as a demonstration of the broadband potential of push-pull PAs at RF frequencies. Next, the two most popular techniques for back-off efficiency enhancement, i.e., ET and load modulation, were studied and the principle of load modulation was found to be more suitable for broadband signal transmission. The Doherty architecture is the most common implementation of load modulation and it comes in two basic variations, the PCL and SCL DPAs. The original architecture concepts are not only band limited but also ill-suited for high frequency designs where the transistors' parasitics introduce significant effect. However, later literature expanded on the original concept of the PCL variation which provided the needed flexibility for wider bandwidth implementations at a higher frequency. Using the broadband implementation and the co-design methodology two push-pull amplifiers were used in a PCL DPA topology and demonstrated that the push-pull utilization doesn't have a significant impact on the bandwidth of the output combiner as an octave bandwidth was achieved with the use of digital Doherty. Lastly, the thesis proposes a new approach for designing high power DPAs with extended bandwidth. It starts with a generic SCL DPA architecture to derive the equations that relate its underlying combiner's ABCD parameters to the transistor's optimum impedance and load impedance. These equations featured the possibility of significantly increasing the load impedance in SCL DPA compared to the one of the popular PCL DPA architecture. This is particularly beneficial when targeting very high power DPAs for macro-cell base stations and broadcast applications where very low load impedance can seriously complicate the design and limit the achievable bandwidth. To further maximize the load impedance increase, the proposed SCL DPA uses a push-pull topology for the main and peaking amplifier stages. A low-loss planar balanced to unbalanced transformer (balun) combiner network is then utilized to realize the SCL DPA combining. The proposed approach was finally applied to design a proof-of-concept 350 W SCL DPA which operates over the band spanning from 720 to 980 MHz. The prototype demonstrated a peak output power of about 55 dBm over a 30% FBW with a 6 dB back-off efficiency, measured using pulsed signal, between 46.6% and 54.6%. Furthermore, the modulated signal based measurement results confirmed the linearizability of the SCL DPA prototype while maintaining a back-off efficiency over 50% for a 7.1 dB peak to average power ratio signal.

Download or read book Diplexing Distributed Power Amplifier for Mobile Applications written by Wei Wang and published by . This book was released on 2012 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Design of a Modified Doherty Power Amplifier for Wideband Code Division Multiple Access Basestations written by David Beishline and published by . This book was released on 2004 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wideband Active Load Modulation in RF Power Amplifiers written by Christian Karl Musolff and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multistage Broadband Amplifiers Based on GaNHEMT Technology for 3G 4G Base Station Applications with Extremely High Bandwidth written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: GaN HFETs have been proposed for high power high linearity and high bandwidth applications andreached tremendous output power levels [1]. However, there are relatively few circuit examples especially for wideband power amplifiers fulfilling the requirements of future multiband/multistandard capable 3G/4G base stations. This work presents first promising results of realised GaN based wideband power amplifier demonstrators for the mentionedfield of application. Two different amplifier concepts for thefinal stage of a power amplifier module for medium range multiband base station applications in the L- and S-Bandhave been implemented as first amplifier demonstrators. Theamplifiers have been characterized by using single carrierW-CDMA signals and showed a promising high bandwidthfor output power levels up to> 10 W while meeting the3GPP ACLR specification in a wide frequency range.

Download or read book RF Power Amplifiers for Wireless Communications written by Steve C. Cripps and published by Artech House Publishers. This book was released on 2006-01-01 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively revised edition offers a comprehensive, practical, up-to-date understanding of how to tackle a power amplifier design with confidence and quickly determine the cause of malfunctioning hardware.

Download or read book Op Amps for Everyone written by Ron Mancini and published by Newnes. This book was released on 2003 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The operational amplifier ("op amp") is the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems. Almost every electronic device uses at least one op amp. This book is Texas Instruments' complete professional-level tutorial and reference to operational amplifier theory and applications. Among the topics covered are basic op amp physics (including reviews of current and voltage division, Thevenin's theorem, and transistor models), idealized op amp operation and configuration, feedback theory and methods, single and dual supply operation, understanding op amp parameters, minimizing noise in op amp circuits, and practical applications such as instrumentation amplifiers, signal conditioning, oscillators, active filters, load and level conversions, and analog computing. There is also extensive coverage of circuit construction techniques, including circuit board design, grounding, input and output isolation, using decoupling capacitors, and frequency characteristics of passive components. The material in this book is applicable to all op amp ICs from all manufacturers, not just TI. Unlike textbook treatments of op amp theory that tend to focus on idealized op amp models and configuration, this title uses idealized models only when necessary to explain op amp theory. The bulk of this book is on real-world op amps and their applications; considerations such as thermal effects, circuit noise, circuit buffering, selection of appropriate op amps for a given application, and unexpected effects in passive components are all discussed in detail. *Published in conjunction with Texas Instruments *A single volume, professional-level guide to op amp theory and applications *Covers circuit board layout techniques for manufacturing op amp circuits.

Download or read book Doherty Power Amplifiers written by Bumman Kim and published by Academic Press. This book was released on 2018-03-28 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doherty Power Amplifiers: From Fundamentals to Advanced Design Methods is a great resource for both RF and microwave engineers and graduate students who want to understand and implement the technology into future base station and mobile handset systems. The book introduces the very basic operational principles of the Doherty Amplifier and its non-ideal behaviors. The different transconductance requirements for carrier and peaking amplifiers, reactive element effect, and knee voltage effect are described. In addition, several methods to correct imperfections are introduced, such as uneven input drive, gate bias adaptation, dual input drive and the offset line technique. Advanced design methods of Doherty Amplifiers are also explained, including multistage/multiway Doherty power amplifiers which can enhance the efficiency of the amplification of a highly-modulated signal. Other covered topics include signal tracking operation which increases the dynamic range, highly efficient saturated amplifiers, and broadband amplifiers, amongst other comprehensive, related topics. Specifically written on the Doherty Power Amplifier by the world’s leading expert, providing an in-depth presentation of principles and design techniques Includes detailed analysis on correcting non-ideal behaviors of Doherty Power Amplifiers Presents advanced Doherty Power Amplifier architectures

Download or read book Radio Frequency Transistors written by Helge Granberg and published by Elsevier. This book was released on 2013-10-22 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellular telephones, satellite communications and radar systems are adding to the increasing demand for radio frequency circuit design principles. At the same time, several generations of digitally-oriented graduates are missing the essential RF skills. This book contains a wealth of valuable design information difficult to find elsewhere. It's a complete 'tool kit' for successful RF circuit design. Written by experienced RF design engineers from Motorola's semiconductors product section.Book covers design examples of circuits (e.g. amplifiers; oscillators; switches; pulsed power; modular systems; wiring state-of-the-art devices; design techniques).

Download or read book Communication Systems for the Mobile Information Society written by Martin Sauter and published by John Wiley & Sons. This book was released on 2006-07-11 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many wireless systems like GSM, GPRS, UMTS, Bluetooth, WLAN or WiMAX offer possibilities to keep people connected while on the move. In this flood of technology and claims that one single resource will serve all our needs, this book seeks to enable readers to examine and understand each technology, and how to utilise several different systems for the best results. Communication Systems for the Mobile Information Society not only contains a technical description of the different wireless systems available today, but also explains the thoughts that are behind the different mechanisms and implementations; not only the 'how' but also the 'why' is in focus. Thus the advantages and also limitations of each technology become apparent. Provides readers with a solid introduction to major global wireless standards and compares the different wireless technologies and their applications Describes the different systems based on the standards, their practical implementation and the design assumptions that were made The performance and capacity of each system in practice is analyzed and explained, accompanied with practical tips on how to discover the functionality of different networks by the readers themselves Questions at the end of each chapter and answers on the accompanying website make this book ideal for self study or as course material Illustrated with many realistic examples of how mobile people can stay in touch with other people, the Internet and their corporate intranet This book is an essential resource for telecommunication engineers, professionals and computer science and electrical engineering students who want to get a thorough end-to-end understanding of the different technical concepts of the systems on the market today.

Download or read book HSDPA HSUPA for UMTS written by Harri Holma and published by John Wiley & Sons. This book was released on 2007-01-11 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the editors of the highly successful WCDMA for UMTS, this new book provides a comprehensive and up-to-date reference to High Speed Packet Access (HSPA) technologies for WCDMA. The editors cover both HSDPA and HSUPA, including an in-depth description and explanation of 3GPP standards, and expected performance based on simulations and first measurements. The text also discusses the impact of HSDPA and HSUPA on network dimensioning, covers applications and end-to-end performance in detail, and includes a section on radio frequency requirements and terminal design considerations. The most comprehensive and advanced guide to the HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access) technologies and standardisation, HSDPA/HSUPA for UMTS: Analyses the impact of HSDPA/HSUPA on network dimensioning, discussing co-existence with R99 (Release 99) and GPRS/EDGE (General Packet Radio Services/ Enhanced Data GSM Environment) Contains a section on applications and end-to-end (e2e) performance Includes a chapter on radio frequency (RF) requirements and terminal design considerations, covering different RF bands, multi-band HSDPA and multi-mode HSDPA+EDGE challenges, power consumption Provides numerous illustrations of 3GPP (Third Generation Partnership Project) standards and performance This title provides excellent coverage of the area for system, element and chip designers, network planners, technical mangers with vendors, operators and application developers. It is also ideal for postgraduates and researchers in related areas.

Download or read book The Evolution of Untethered Communications written by National Research Council and published by National Academies Press. This book was released on 1998-01-01 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to a request from the Defense Advanced Research Projects Agency, the committee studied a range of issues to help identify what strategies the Department of Defense might follow to meet its need for flexible, rapidly deployable communications systems. Taking into account the military's particular requirements for security, interoperability, and other capabilities as well as the extent to which commercial technology development can be expected to support these and related needs, the book recommends systems and component research as well as organizational changes to help the DOD field state-of-the-art, cost-effective untethered communications systems. In addition to advising DARPA on where its investment in information technology for mobile wireless communications systems can have the greatest impact, the book explores the evolution of wireless technology, the often fruitful synergy between commercial and military research and development efforts, and the technical challenges still to be overcome in making the dream of "anytime, anywhere" communications a reality.

Download or read book Broadband Wireless Communications written by Marco Luise and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Broadband Wireless Access is a highly challenging and fast changing area of multimedia radio communications. These papers on the subject are the proceedings of the 9th Tyrrhenian Workshop, held in Lerici, Italy, September 1997. They provide a prospect on the state of the art and future development, with a sufficiently wide focus to cover technological, architectural and regulatory issues. Emphasis is given to those advances of digital signal processing techniques, microwave mono lithic integrated circuits and smart antennae that will allow the design of low cost user terminals with advanced capabilities. Specific attention is also devoted to the protocols these new terminals will use to access the radio medium, and to the kind of services that will eventually be provided to the end-user in the future. With contributions from worldwide experts, the material presented here is a timely and high-level overview of the field, and as well as being informative is a useful tool for promoting further investigation into the area of multimedia radio communications.