Download or read book Envelope Switched Doherty Power Amplifier For RF Applications Preprint written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report was developed under a SBIR contract. A new concept of envelope switched Doherty amplifier is introduced. The proposed amplifier maintains maximum efficiency over a wide range of output power fluctuation. The essential idea is to drive two amplifier devices connected in Doherty configuration with a pulsed envelope signal. A high-Q, low loss filter is placed at the output to recover for linearity and to generate a time-varying equivalent load impedance for optimal efficiency performance. Ideally, for a pair of equally sized and identically biased Class B amplifiers, a maximum efficiency, 78.5%, should be maintained all the way down to the 6dB output back-off level. This concept is demonstrated in the experiment with a pair of GaAs FETs at a frequency of 1.87GHz in the PCS band. A maximum output power of 32.7dBm with a PAE of 46% is measured and a PAE of 34.4% is measured at 6dB back-off level including the filter loss at the power amplifier (PA) output. The proposed architecture can be applied in designing high efficiency PAs with non-constant envelope modulations.

Download or read book Design and Implementation of an Envelope Tracking Power Amplifier Using Switched Amplifiers and Slow Envelopes written by Pedro Pablo Vizarreta Paz and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Switchmode RF and Microwave Power Amplifiers written by Andrei Grebennikov and published by Academic Press. This book was released on 2012-06-28 with total page 701 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combining solid theoretical discussions with practical design examples, this book is an essential reference on developing RF and microwave switchmode power amplifiers. With this book you will be able to: Design high-efficiency RF and microwave power amplifiers on different types of bipolar and field-effect transistors using well-known and novel theoretical approaches, nonlinear simulation tools, and practical design techniques 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 Understand the theory and practical implementation of load-network design techniques based on lumped and transmission-line elements Combine multi-stage Doherty architecture and switchmode power amplifiers to significantly increase efficiency of the entire radio transmitter Learn the different types of predistortion linearization techniques required to improve the quality of signal transmission in a nonlinear amplifying system New to this edition: Comprehensive overview of different Doherty architectures which are, and will be used in modern communication systems to save power consumption and reduce costs A new chapter on analog and digital predistortion techniques Coverage of broadband Class-F power amplifiers, high-power inverse Class-F power amplifiers for WCDMA systems, broadband Class-E techniques Unique focus on switchmode RF and microwave power amplifiers that are widely used in cellular/wireless, satellite and radar communication systems and which offer major power consumption savings Complete coverage of the new Doherty architecture which offers major efficiencies and savings on power consumption Balances theory with practical implementatation, avoiding a cookbook approach, enabling engineers to develop better designs Trusted content from leading figures in the field with a Foreword of endorsement by Zoya Popovic

Download or read book Reconfigurable RF Power Amplifiers on Silicon for Wireless Handsets written by Laurent Leyssenne and published by Springer Science & Business Media. This book was released on 2011-01-11 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reconfigurable RF Power Amplifiers on Silicon for Wireless Handsets is intended to designers and researchers who have to tackle the efficiency/linearity trade-off in modern RF transmitters so as to extend their battery lifetime. High data rate 3G/4G standards feature broad channel bandwidths, high dynamic range and critical envelope variations which generally forces the power amplifier (PA) to operate in a low efficiency “backed-off” regime. Classic efficiency enhancement techniques such as Envelope Elimination and Restoration reveal to be little compliant with handset-dedicated PA implementation due to their channel-bandwidth-limited behavior and their increased die area consumption and/or bill-of-material. The architectural advances that are proposed in this book circumvent these issues since they put the stress on low die-area /low power-consumption control circuitry. The advantages of silicon over III/V technologies are highlighted by several analogue signal processing techniques that can be implemented on-chip with a power amplifier. System-level and transistor-level simulations are combined to illustrate the principles of the proposed power adaptive solutions. Measurement on BICMOS demonstrators allows validating the functionality of dynamic linearity/efficiency management. In Reconfigurable RF Power Amplifiers on Silicon for Wireless Handsets, PA designers will find a review of technologies, architectures and theoretical formalisms (Volterra series...) that are traditionally related to PA design. Specific issues that one encounters in power amplifiers (such as thermal / memory effects, stability, VSWR sensitivity...) and the way of overcoming them are also extensively considered throughout this book.

Download or read book Linear and Switch Mode RF Power Amplifiers written by Abdullah Eroglu and published by CRC Press. This book was released on 2017-09-06 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF power amplifiers are implemented in communication, semiconductor wafer processing, magnetic resonance imaging (MRI), and radar systems to produce RF signal with the desired characteristics to perform several critical tasks in the entire system. They can be designed to operate in linear or switch-mode, depending on the specific application. This book explores the design and implementation methods for both linear and switch-mode amplifiers with real world engineering problems. The text discusses phased controlled switch-mode amplifiers and distortion and modulation effects in RF amplifiers. It illustrates the interface and integration of components and sub-systems for RF amplifiers. The material is further reinforced with MATLAB design files.

Download or read book Envelope tracking Common drain CMOS Power Amplifier with a Switching only Supply Modulator for LTE Applications written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book GaN on Si RF Switched Mode Power Amplifiers for Non constant Envelope Signals written by Shishir Ramasare Shukla and published by . This book was released on 2015 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work implements three switched mode power amplifier topologies namely inverse class-D (CMCD), push-pull class-E and inverse push-pull class-E, in a GaN-on-Si process for medium power level (5-10W) femto/pico-cells base-station applications. The presented power amplifiers address practical implementation design constraints and explore the fundamental performance limitations of switched-mode power amplifiers for cellular band. The designs are analyzed and compared with respect to non-idealities like finite on-resistance, finite-Q of inductors, bond-wire effects, input signal duty cycle, and supply and component variations. These architectures are designed for non-constant envelope inputs in the form of digitally modulated signals such as RFPWM, which undergo duty cycle variation. After comparing the three topologies, this work concludes that the inverse push-pull class-E power amplifier shows lower efficiency degradation at reduced duty cycles. For GaN based discrete power amplifiers which have less drain capacitance compared to GaAs or CMOS and where the switch loss is dominated by wire-bonds, an inverse push-pull class-E gives highest output power at highest efficiency. Push-pull class-E can give efficiencies comparable to inverse push-pull class-E in presence of bondwires on tuning the Zero-Voltage Switching (ZVS) network components but at a lower output power. Current-Mode Class-D (CMCD) is affected most by the presence of bondwires and gives least output power and efficiency compared to other two topologies. For systems dominated by drain capacitance loss or which has no bondwires, the CMCD and push-pull class-E gives better output power than inverse push-pull class-E. However, CMCD is more suitable for high breakdown voltage process.

Download or read book Design and Optimization of the Doherty Power Amplifier for Broadband Applications written by Guolin Sun and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Switchmode RF Power Amplifiers written by Andrei Grebennikov and published by Newnes. This book was released on 2007 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The authors' combination of solid theoretical discussion and practical design examples makes this an essential reference for RF and microwave engineers."--BOOK JACKET.

Download or read book Envelope Amplifier Design for Wireless Base station Power Amplifiers written by Chin Hsia and published by . This book was released on 2010 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to deliver high data rates, modern wireless communication systems transmit complex modulated signals with high peak-to-average ratio, which demands wide bandwidth and stringent linearity performance for power amplifiers. To satisfy spectral mask regulations and achieve adequate error vector magnitude, power amplifiers typically operate at 6 to 10 dB back-off from the maximum output power, leading to low efficiency. To overcome the low efficiency problem, the envelope tracking power amplifier architecture has been proposed for this type of application due to its feature of high efficiency over a wide power range. The overall efficiency of an envelope tracking system relies not only on performance of the RF power amplifier but also on that of an envelope amplifier that provides a dynamically varying power supply voltage. This dissertation focuses on envelope amplifier design for efficiency enhancement of envelope tracking power amplifiers. First, the envelope tracking power amplifier architecture is analyzed, and the efficiency of a RF transistor in the envelope tracking technique is described. Then envelope amplifier behavior is investigated and a general purpose simulator is developed for analyzing and designing an envelope amplifier. Power loss and efficiency of the envelope amplifier is analyzed and compared with experimental results. The design of envelope amplifiers for high voltage (> 30 V) envelope tracking applications is described. A high voltage envelope amplifier is designed, implemented and verified. The overall envelope tracking system employing a GaN-HEMT RF transistor is demonstrated. Finally, a new architecture is developed for the efficiency enhancement of envelope amplifiers, using a digitally assisted controller design. Digital control is utilized to mitigate delay in the control loop inside the envelope amplifier, leading to lower overall power dissipation. A novel envelope amplifier architecture with dual-switcher stages based on the digitally-assisted control strategy is proposed, designed and implemented. The strategy is demonstrated to improve the efficiency of envelope amplifier as well as the system overall efficiency. The resulting performance of envelope tracking system employing a GaAs high voltage HBT with a single carrier W-CDMA input demonstrated state-of-the-art efficiency with good linearity performance.

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 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 Wide Bandgap Based Devices written by Farid Medjdoub and published by MDPI. This book was released on 2021-05-26 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wide bandgap (WBG) semiconductors hold the potential to advance the global industry in the same way that, more than 50 years ago, the invention of the silicon (Si) chip enabled the modern computer era. SiC- and GaN-based devices are starting to become more commercially available. Smaller, faster, and more efficient than their counterpart Si-based components, these WBG devices also offer greater expected reliability in tougher operating conditions. Furthermore, in this frame, a new class of microelectronic-grade semiconducting materials that have an even larger bandgap than the previously established wide bandgap semiconductors, such as GaN and SiC, have been created, and are thus referred to as “ultra-wide bandgap” materials. These materials, which include AlGaN, AlN, diamond, Ga2O3, and BN, offer theoretically superior properties, including a higher critical breakdown field, higher temperature operation, and potentially higher radiation tolerance. These attributes, in turn, make it possible to use revolutionary new devices for extreme environments, such as high-efficiency power transistors, because of the improved Baliga figure of merit, ultra-high voltage pulsed power switches, high-efficiency UV-LEDs, and electronics. This Special Issue aims to collect high quality research papers, short communications, and review articles that focus on wide bandgap device design, fabrication, and advanced characterization. The Special Issue will also publish selected papers from the 43rd Workshop on Compound Semiconductor Devices and Integrated Circuits, held in France (WOCSDICE 2019), which brings together scientists and engineers working in the area of III–V, and other compound semiconductor devices and integrated circuits. In particular, the following topics are addressed: – GaN- and SiC-based devices for power and optoelectronic applications – Ga2O3 substrate development, and Ga2O3 thin film growth, doping, and devices – AlN-based emerging material and devices – BN epitaxial growth, characterization, and devices

Download or read book Energy Harvesting written by Apostolos Georgiadis and published by Cambridge University Press. This book was released on 2021-01-21 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough treatment of energy harvesting technologies, highlighting radio frequency (RF) and hybrid-multiple technology harvesting. The authors explain the principles of solar, thermal, kinetic, and electromagnetic energy harvesting, address design challenges, and describe applications. The volume features an introduction to switched mode power converters and energy storage and summarizes the challenges of different system implementations, from wireless transceivers to backscatter communication systems and ambient backscattering. This practical resource is essential for researchers and graduate students in the field of communications and sensor technology, in addition to practitioners working in these fields.

Download or read book RF and Microwave Power Amplifier Design written by Andrei Grebennikov and published by McGraw Hill Professional. This book was released on 2004-09-15 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a rigorous tutorial on radio frequency and microwave power amplifier design, teaching the circuit design techniques that form the microelectronic backbones of modern wireless communications systems. Suitable for self-study, corporate training, or Senior/Graduate classroom use, the book combines analytical calculations and computer-aided design techniques to arm electronic engineers with every possible method to improve their designs and shorten their design time cycles.

Download or read book Mechanical Behavior of Materials written by Marc A. Meyers and published by . This book was released on 2008 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes numerous examples and problems for student practice, this textbook is ideal for courses on the mechanical behaviour of materials taught in departments of mechanical engineering and materials science.

Download or read book Microwave Electronics written by Giovanni Ghione and published by Cambridge University Press. This book was released on 2018 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: A self-contained guide to microwave electronics, covering passive and active components, linear, low-noise and power amplifiers, microwave measurements, and CAD techniques. It is the ideal text for graduate and senior undergraduate students taking courses in microwave and radio-frequency electronics, as well as professional microwave engineers.