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 Design of a Broadband Doherty Power Amplifier with a Graphical User Interface Tool written by Pingzhu Gong and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel broadband Doherty Power Amplifier (DPA) design for 4G applications is presented with the aid of a modified version of DPA Graphical User Interface (GUI) Tool. Compared to the previous version, the new GUI uses Output Back-Off (OBO) as the input instead of the peak power ratio of the DPA Main and auxiliary PAs. Furthermore, the load impedance seen by the Main PA (MPA) at 2nd harmonic and 3rd harmonic can be directly controlled from the GUI. In this design, Main PA is operated under class F mode and the auxiliary PA is operated under Class C mode. The main PA is biased at -3.2 V at the gate (lower than typical values: -2.7 V ~ -3 V) to boost the efficiency. A new parasitic network with simple structure is extracted using OSU Embedding Model. Design procedures are stated as follows. Fundamental load impedances seen by both PAs are generated by GUI at Current source Reference Plane (CRP). Then, the Output Matching Network (OMN) is synthesized at CRP for both PAs separately. At last, the input matching network and the equal split Wilkinson power divider are designed to realize the broadband DPA. Electromagnetic (EM) Co-simulation result shows the DPA achieves 59.4-62.2% drain efficiency at 8-dB OBO at 1.5-2.2GHz with a gain of 10-13dB. The peak power range is between 43.7 dBm and 44.5 dBm. The THD and IM3 is around -15dB at back off power. The performance of the proposed DPA iii design is shown to be comparable to state-of-the-art designs, which indicates our DPA has a good performance.

Download or read book On the Design of High efficiency RF Doherty Power Amplifiers written by Mehran Yahyavi and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power amplifiers (PAs) are one of the most crucial elements in wireless standards becasue they are the most power hungry subsystems. These elements have to face an important issue, which is the power efficiency, a fact related with the output back-off (OBO). But the OBO depends on the kind of modulated signal, in proportion to the modulated signal peak-to-average power ratio (PAPR). The higuer is the data rate, the higer is the OBO, and consequently the lower is the efficiency. A low efficiency of PAs causes the waste of energy as heat. Furthermore, the trade-off between linearity and efficiency in PAs is another major issue. To cope with the undesired circumstances producing efficiency degradation, the Doherty power amplifier (DPA) is one of the useful techniques which provide high efficiency for high PAPR of modern communication signals. Nevertheless, the limited bandwidth (BW) of this kind of PAs (about 10% of fractional bandwidth) and its importance (in modern wireless systems such as LTE, WiMAX, Wi-Fi and satellite systems) have encouraged the researchers to improve this drawback in recent years. Some typical BW limiting factors effect on the performance of DPAs: i) quarter-wave length transformers, ii) phase compensation networks in/output matching circuits, iii) offset lines and device non-idealities; The quarter-wave length transformers performs as an inverter impedance in the load modulation technique of DPAs. The future objective in designing DPAs is to decrease the impact of these issues. In this context, this PhD-thesis is focused on improving fractional bandwidth of DPAs using the new methods that are related to impedance transformers instead of impedance inverters in the load modulation technique. This study is twofold. First, it is presented a novel DPA where a wideband GaN DPA in the 2.5 GHz band with an asymmetrical Wilkinson splitter. The impedance transformer of the proposed architecture is based on a matching network including a tapered line with multi-section transformer in the main stage. The BW of this DPA has ranged from 1.8 to 2.7 GHz. Plus, the obtained power efficiency (drain) is higher than 33% in the whole BW at both maximum and OBO power levels. Second, based on the benefits of the Klopfenstein taper, a promising DPA design is proposed where a Klopfenstein taper replaces the tapered line. In fact, this substitution results on reducing the reflection coefficient of the transformer. From a practical prototype realization of this novel Doherty-like PA in the 2.25 GHz band, this modification has demonstrated that the resulting DPA BW is increased in comparison to the conventional topology while keeping the efficiency figures. Moreover, this study also shows that the Klopfenstein taper based design allows an easy tuning of the group delay through the output reactance of the taper, resulting in a more straightforward adjustments than other recently published designs where the quarter-wave transformer is replaced by multi-section transmission lines (hybrid or similar). Experimental results have shown 43-54% of drain efficiency at 42 dBm output power, in the range of 1.7 to 2.75 GHz. Concretely, the results presented in this novel Doherty-like PA implies an specific load modulation technique that uses the mixed Klopfenstein tapered line together with a multi-section transformer in order to obtain high bandwidth with the usual efficiency in DPAs.

Download or read book A Doherty Power Amplifier with Extended Bandwidth and Reconfigurable Back off Level written by Yu-Ting David Wu and published by . This book was released on 2013 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wireless standards are designed to be spectrally efficient to address the high cost of licensing wireless spectra. Unfortunately, the resulting signals have a high peak-to-average ratio that reduces the base station power amplifier efficiency at the back-off power level. The wasted energy is converted to heat that degrades the device reliability and increases the base-station's carbon footprint and cooling requirements. In addition, these new standards place stringent requirements on the amplifier output power, linearity, efficiency, and bandwidth. To improve the back-off efficiency, a Doherty amplifier, which uses two device in parallel for back-off efficiency enhancement, is deployed in a typical base station. Unfortunately, the conventional Doherty amplifier is narrowband and thus cannot satisfy the bandwidth requirement of the modern base station that needs to support multiple standards and backward compatibility. In this thesis, we begin by studying the class F/F-1 high efficiency mode of operation. To this end, we designed a narrowband, harmonically-tuned 3.3 GHz, 10 W GaN high efficiency amplifier. Next, we investigate how to simultaneously achieve high efficiency and broad bandwidth by harnessing the simplified real frequency technique for the broadband matching network design. A 2 to 3 GHz, 45 W GaN amplifier and a 650 to 1050 MHz, 45 W LDMOS amplifier were designed. Finally, we analyze the conventional Doherty amplifier to determine the cause of its narrow bandwidth. We find that the narrow bandwidth can be attributed to the band-limited quarter-wave transformer as well as the widely adopted traditional design technique. As an original contribution to knowledge, we propose a novel Doherty amplifier configuration with intrinsically broadband characteristics by analyzing the load modulation concept and the conventional Doherty amplifier. The proposed amplifier uses asymmetrical drain voltage biases and symmetrical devices and it does not require a complex mixed-signal setup. To demonstrate the proposed concept in practice, we designed a 700 to 1000 MHz, 90 W GaN broadband Doherty amplifier. Moreover, to show that the proposed concept is applicable to high power designs, we designed a 200 W GaN broadband Doherty amplifier in the same band. In addition, to show that the technique is independent of the device technology, we designed a 700 to 900 MHz, 60 W LDMOS broadband Doherty amplifier. Using digital pre-distortion, the three prototypes were shown to be highly linearizable when driven with wideband 20 MHz LTE and WCDMA modulated signals and achieved excellent back-off efficiency. Lastly, using the insights from the previous analyses, we propose a novel mixed-technology Doherty amplifier with an extended and reconfigurable back-off level as well as an improved power utilization factor. The reconfigurability of the proposed amplifier makes it possible to customize the back-off level to achieve the highest average efficiency for a given modulated signal without redesigning the matching networks. A 790 to 960 MHz, 180 W LDMOS/GaN Doherty amplifier demonstrated the extended bandwidth and reconfigurability of the back-off level. The proposed amplifier addresses the shortcomings of the conventional Doherty amplifier and satisfies the many requirements of a modern base station power amplifier.

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 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 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 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 An Introduction to LTE written by Christopher Cox and published by John Wiley & Sons. This book was released on 2014-05-12 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following on from the successful first edition (March 2012), this book gives a clear explanation of what LTE does and how it works. The content is expressed at a systems level, offering readers the opportunity to grasp the key factors that make LTE the hot topic amongst vendors and operators across the globe. The book assumes no more than a basic knowledge of mobile telecommunication systems, and the reader is not expected to have any previous knowledge of the complex mathematical operations that underpin LTE. This second edition introduces new material for the current state of the industry, such as the new features of LTE in Releases 11 and 12, notably coordinated multipoint transmission and proximity services; the main short- and long-term solutions for LTE voice calls, namely circuit switched fallback and the IP multimedia subsystem; and the evolution and current state of the LTE market. It also extends some of the material from the first edition, such as inter-operation with other technologies such as GSM, UMTS, wireless local area networks and cdma2000; additional features of LTE Advanced, notably heterogeneous networks and traffic offloading; data transport in the evolved packet core; coverage and capacity estimation for LTE; and a more rigorous treatment of modulation, demodulation and OFDMA. The author breaks down the system into logical blocks, by initially introducing the architecture of LTE, explaining the techniques used for radio transmission and reception and the overall operation of the system, and concluding with more specialized topics such as LTE voice calls and the later releases of the specifications. This methodical approach enables readers to move on to tackle the specifications and the more advanced texts with confidence.

Download or read book Switchmode RF and Microwave Power Amplifiers written by Andrei Grebennikov and published by Academic Press. This book was released on 2021-03-19 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: Switchmode RF and Microwave Power Amplifiers, Third Edition is an essential reference book on developing RF and microwave switchmode power amplifiers. The book combines theoretical discussions with practical examples, allowing readers to design high-efficiency RF and microwave power amplifiers on different types of bipolar and field-effect transistors, design any type of high-efficiency switchmode power amplifiers operating in Class D or E at lower frequencies and in Class E or F and their subclasses at microwave frequencies with specified output power, also providing techniques on how to design multiband and broadband Doherty amplifiers using different bandwidth extension techniques and implementation technologies. This book provides the necessary information to understand the theory and practical implementation of load-network design techniques based on lumped and transmission-line elements. It brings a unique focus on switchmode RF and microwave power amplifiers that are widely used in cellular/wireless, satellite and radar communication systems which offer major power consumption savings. Provides a complete history of high-efficiency Class E and Class F techniques Presents a new chapter on Class E with shunt capacitance and shunt filter to simplify the design of high-efficiency power amplifier with broader frequency bandwidths Covers different Doherty architectures, including integrated and monolithic implementations, which are and will be, used in modern communication systems to save power consumption and to reduce size and costs Includes extended coverage of multiband and broadband Doherty amplifiers with different frequency ranges and output powers using different bandwidth extension techniques Balances theory with practical implementation, avoiding a cookbook approach and enabling engineers to develop better designs, including hybrid, integrated and monolithic implementations

Download or read book Fundamentals of RF and Microwave Transistor Amplifiers written by Inder Bahl and published by John Wiley & Sons. This book was released on 2009-06-17 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help readers test their basic amplifier and circuit design skills-and more than half of the problems feature fully worked-out solutions. With an emphasis on theory, design, and everyday applications, this book is geared toward students, teachers, scientists, and practicing engineers who are interested in broadening their knowledge of RF and microwave transistor amplifier circuit design.

Download or read book Advanced Techniques in RF Power Amplifier Design written by Steve C. Cripps and published by Artech House. This book was released on 2002 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This much-anticipated volume builds on the author's best selling and classic work, RF Power Amplifiers for Wireless Communications (Artech House, 1999), offering experienced engineers a more in-depth understanding of the theory and design of RF power amplifiers. An invaluable reference tool for RF, digital and system level designers, the book includes discussions on the most critical topics for professionals in the field, including envelope power management schemes and linearization.

Download or read book Localization Algorithms and Strategies for Wireless Sensor Networks Monitoring and Surveillance Techniques for Target Tracking written by Mao, Guoqiang and published by IGI Global. This book was released on 2009-05-31 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless localization techniques are an area that has attracted interest from both industry and academia, with self-localization capability providing a highly desirable characteristic of wireless sensor networks. Localization Algorithms and Strategies for Wireless Sensor Networks encompasses the significant and fast growing area of wireless localization techniques. This book provides comprehensive and up-to-date coverage of topics and fundamental theories underpinning measurement techniques and localization algorithms. A useful compilation for academicians, researchers, and practitioners, this Premier Reference Source contains relevant references and the latest studies emerging out of the wireless sensor network field.

Download or read book RF and Microwave Transmitter Design written by Andrei Grebennikov and published by John Wiley & Sons. This book was released on 2011-09-19 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF and Microwave Transmitter Design is unique in its coverage of both historical transmitter design and cutting edge technologies. This text explores the results of well-known and new theoretical analyses, while informing readers of modern radio transmitters' pracitcal designs and their components. Jam-packed with information, this book broadcasts and streamlines the author's considerable experience in RF and microwave design and development.

Download or read book Recent Technical Developments in Energy Efficient 5G Mobile Cells written by Raed A. Abd-Alhameed and published by MDPI. This book was released on 2020-06-17 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the true innovation in engineering design that may be promoted by blending together models and methodologies from different disciplines, and, in this book, the target was exactly to follow this approach to deliver a new disruptive architecture to deliver these next-generation mobile small cell technologies. According to this design philosophy, the work within this book resides in the intersection of engineering paradigms that includes “cooperation”, “network coding”, and “smart energy-aware frontends”. These technologies will not only be considered as individual building blocks, but re-engineered according to an inter-design approach resulting in the enabler for energy efficient femtocell-like services on the move. The book aims to narrow the gap between the current networking technologies and the foreseen requirements that are targeted at the future development of the 5G mobile and wireless communications networks in terms of the higher networking capacity, the ability to support more users, the lower cost per bit, the enhanced energy efficiency, and adaptability to new services and devices (for example, smart cities, and the Internet of things (IoT)).

Download or read book Millimeter Wave Antennas Configurations and Applications written by Jaco du Preez and published by Springer. This book was released on 2016-06-20 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprehensively reviews the state of the art in millimeter-wave antennas, traces important recent developments and provides information on a wide range of antenna configurations and applications. While fundamental theoretical aspects are discussed whenever necessary, the book primarily focuses on design principles and concepts, manufacture, measurement techniques, and practical results. Each of the various antenna types scalable to millimeter-wave dimensions is considered individually, with coverage of leaky-wave and surface-wave antennas, printed antennas, integrated antennas, and reflector and lens systems. The final two chapters address the subject from a systems perspective, providing an overview of supporting circuitry and examining in detail diverse millimeter-wave applications, including high-speed wireless communications, radio astronomy, and radar. The vast amount of information now available on millimeter-wave systems can be daunting for researchers and designers entering the field. This book offers readers essential guidance, helping them to gain a thorough understanding based on the most recent research findings and serving as a sound basis for informed decision-making.

Download or read book Load Pull Techniques with Applications to Power Amplifier Design written by Fadhel M. Ghannouchi and published by Springer Science & Business Media. This book was released on 2012-06-06 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book on load-pull systems is intended for readers with a broad knowledge of high frequency transistor device characterization, nonlinear and linear microwave measurements, RF power amplifiers and transmitters. Load-Pull Techniques with Applications to Power Amplifier Design fulfills the demands of users, designers, and researchers both from industry and academia who have felt the need of a book on this topic. It presents a comprehensive reference spanning different load-pull measurement systems, waveform measurement and engineering systems, and associated calibration procedures for accurate large signal characterization. Besides, this book also provides in-depth practical considerations required in the realization and usage of load-pull and waveform engineering systems. In addition, it also provides procedure to design application specific load-pull setup and includes several case studies where the user can customize architecture of load-pull setups to meet any specific measurement requirements. Furthermore, the materials covered in this book can be part of a full semester graduate course on microwave device characterization and power amplifier design.