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Development Of A High Efficiency Power Amplifier For Envelope Tracking Applications
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Book Synopsis Development of a High-efficiency Power Amplifier for Envelope Tracking Applications by : Zulhazmi Bin A. Mokhti
Download or read book Development of a High-efficiency Power Amplifier for Envelope Tracking Applications written by Zulhazmi Bin A. Mokhti and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Wideband High Efficiency CMOS Envelope Amplifiers for 4G LTE Handset Envelope Tracking RF Power Amplifiers by : Muhammad Hassan
Download or read book Wideband High Efficiency CMOS Envelope Amplifiers for 4G LTE Handset Envelope Tracking RF Power Amplifiers written by Muhammad Hassan and published by . This book was released on 2012 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fourth generation cellular networks offer performance similar to cable modems while allowing wide mobility. Although the use of orthogonal frequency division multiplexing in fourth generation increases its spectral efficiency but it also increases the peak-to-average power ratio of the transmitted signal. If a conventional power amplifier is used to transmit a high peak-to-average power ratio signal, then to meet the stringent linearity requirements, it will be operating 6 to 10 dB back-off from the maximum output power. This is the region where power amplifier has lower efficiency. To overcome the low efficiency problem, the envelope tracking power amplifier architecture has been proposed in the literature due to its feature of high efficiency over a wide power range. The overall efficiency of the envelope tracking system is the product of the power amplifier efficiency and the envelope amplifier efficiency, which provides the dynamically varying power supply voltage. This dissertation focuses on developing high efficiency envelope amplifiers for wideband applications. First, a CMOS envelope amplifier is developed which cuts the quiescent power dissipation by half over the conventional designs and also employs more accurate current sensing. In order to further improve its efficiency, a dynamic supply is provided on the linear amplifier, which improves the overall efficiency by 6% in measurements. Secondly, modeling of power amplifier operating under envelope shaping is described, in order to accurately predict the efficiency of the envelope amplifier. Also, the stability of the envelope amplifier is analyzed under nonlinear resistive load operation. The overall envelope tracking system achieves a record high efficiency of 43% for 20 MHz LTE signal using a GaAs power amplifier. Finally, another new architecture for CMOS envelope amplifier is developed for efficiency enhancement, using deadband controller. A linearized describing function analysis is done on the proposed architecture, to predict the frequency responses of each block, which matches pretty well with the simulations. The stacked implementation of linear and switching amplifiers allows 6V supply while using all 3.3V devices for them. This leads to integration of envelop amplifiers into submicron CMOS processes.
Book Synopsis Envelope Tracking Power Amplifiers for Wireless Communications by : Zhancang Wang
Download or read book Envelope Tracking Power Amplifiers for Wireless Communications written by Zhancang Wang and published by Artech House. This book was released on 2014-06-01 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Envelope tracking technology is seen as the most promising efficiency enhancement technology for RF power amplifiers for 4G and beyond wireless communications. More and more organizations are investing and researching on this topic with huge potential in academic and commercial areas. This is the first book on the market to offer complete introduction, theory, and design considerations on envelope tracking for wireless communications. This resource presents you with a full introduction to the subject and covers underlying theory and practical design considerations.
Book Synopsis Envelope Amplifier Design for Wireless Base-station Power Amplifiers by : Chin Hsia
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.
Book Synopsis High Efficiency Wideband Envelope Tracking Power Amplifier for Next-generation Wireless Communications by : Myoungbo Kwak
Download or read book High Efficiency Wideband Envelope Tracking Power Amplifier for Next-generation Wireless Communications written by Myoungbo Kwak and published by . This book was released on 2011 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest generation of smart devices deployed in cellular networks has created explosive growth in network data traffic, and the increasing demand for broadband services with higher data rates, require higher peak to average power ratio (PAPR) with wider bandwidth. One of the challenges in the conventional power amplifiers (PAs) with fixed supply voltage, is the degraded efficiency and generated heats at a large back-off to meet tight linearity requirements. This dissertation presents high efficiency wideband envelope tracking power amplifiers for 2.1 GHz micro base-stations and 2.5 GHz wireless mobile applications. By superimposing the envelope signal at the drain such that the RF amplifier operates consistently closer to saturation, the overall efficiency is improved and the generated heat is reduced dramatically. In the first part of the dissertation, a high performance BiCMOS DMOS monolithic envelope amplifier for micro-base station power amplifiers is presented. Due to the low breakdown voltage of the CMOS transistors, the high voltage envelope amplifier has been implemented with discrete components with high voltage process. Compared to these discrete solutions, an integrated circuits implementation for the envelope amplifier brings many benefits. The design of monolithic envelope amplifiers for high voltage (VDD = 15 V) envelope tracking applications, and the design techniques to solve the reliability issues with thin gate oxide is described. The overall envelope tracking system employing a GaN-HEMT RF transistor, and fully integrated high voltage envelope amplifier with a 0.35[mu]m BiCMOS DMOS process, is demonstrated. In the second part, a high-efficiency wideband envelope tracking power amplifier for mobile LTE applications will be presented. The CMOS envelope amplifier with hybrid linear and switcher is designed in a 150 nm CMOS process. The envelope amplifier employs direct sensing of the linear stage current to reduce the propagation delay in the switcher. The strategy is demonstrated to improve the efficiency of the complete envelope tracking power amplifier system. The resulting performance of envelope tracking system employing a GaAs HBT-based RF PA with a 5 MHz LTE signal input demonstrated state-of-the-art efficiency while meet the linearity requirement.
Book Synopsis High Efficiency Linear Envelope Tracking and Envelope Elimination and Restoration Power Amplifier for WLAN OFDM Applications by : Feipeng Wang
Download or read book High Efficiency Linear Envelope Tracking and Envelope Elimination and Restoration Power Amplifier for WLAN OFDM Applications written by Feipeng Wang and published by . This book was released on 2006 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: High efficiency radio frequency (RF) power amplifiers (PAs) are critical in portable battery-operated wireless communication systems because they can dominate the power consumption. Linear power amplifier is required for envelope modulated signal. Traditionally, linear power amplifiers are implemented by "backing-off" the Class-A or Class-AB PA. However for a high peak-to-average (PAR) signal, the average efficiency is much lower than the peak efficiency, which is well down as the inherent trade-off between linearity and efficiency. This dissertation focuses on Envelope Elimination and Restoration (EER) and Envelope Tracking (ET) efficiency enhancement techniques to improve the PA average efficiency for high PAR signal. The EER and ET PA structures are investigated. Wideband ET and "hybrid" EER structures are proposed for WLAN 802.11g signal at 20MHz signal. Two major challenges of the wideband EER and ET PAs are investigated: 1) An adaptive time-alignment algorithm was proposed to calibrate the time-mismatch in wideband EER and ET systems; (2) A high efficiency wideband envelope amplifier is designed for wideband EER and wideband ET applications. A monolithic wideband high efficiency ET power amplifier is designed and implemented for WLAN 802.11g applications in IBM SiGe BiCMOS technology. Digital pre-distortion was implemented to reduce the EVM of the amplifier. The measured overall power-added efficiency of the amplifier is 28% at 20 dBm (100mW) output power.
Book Synopsis High Efficiency Broadband Envelope-Tracking Power Amplifiers by : Jonmei Johana Yan
Download or read book High Efficiency Broadband Envelope-Tracking Power Amplifiers written by Jonmei Johana Yan and published by . This book was released on 2013 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to meet the increasing demand for higher data rates while maximizing spectral efficiency, modern wireless communication systems transmit complex non-constant envelope modulation signals with high peak-to-average ratio (PAPR). As a result, conventional power amplifiers must be operated in back-off, leading to a significant efficiency reduction. Various power amplifier architectures (i.e. Doherty, outphasing, and envelope tracking) have been demonstrated to achieve high efficiency for these high PAPR signals. Unlike the other architectures, the envelope tracking power amplifier (ETPA) makes an excellent candidate for multi-band multi-frequency use, while maintaining high efficiency for high PAPR and under average power back-off, as it is fundamentally immune to changes in the frequency of the carrier; it depends only on the envelope of the RF signal. This dissertation focuses on the design of envelope tracking power amplifiers for enabling broadband wireless communication systems. First, a test-bench for evaluating broadband ETPAs is described. A calibration routine, acting as a pre-equalizer, is used to achieve a flat linear response over the entire instantaneous bandwidth of the system, resulting in less than 1% EVM for a 40 MHz LTE signal. Performances of envelope tracking power amplifiers on this test-bench at various frequencies from UHF to millimeter-wave are evaluated, and record efficiencies are demonstrated. Next, this dissertation describes how in under practical usage, the power transmitted fluctuates as a function of the load demands over time. The long-term efficiency of the ETPA is evaluated using Monte-Carlo simulations based on a projected time-varying power profile. Compared to a Doherty PA with the same peak efficiency, the ETPA can provide more than 1.4x reduction in overall energy consumed. The ETPA thus provides significant opportunities for system energy savings under realistic operation. Thirdly, to accommodate the wide range of carrier frequencies required for numerous emerging wireless systems, a multi-octave RFPA based on a compact GaN stacked IC with RC feedback is designed, fabricated, and evaluated. Multi-octave ET operation was demonstrated from 500 to 1750 MHz with >25% efficiency. Compared to its constant drain voltage counterpart, >2x improvement in RFPA efficiency is observed in ET. Lastly, while the ETPA provides advantages such as broad carrier bandwidths and high efficiency under back-off operation, one of the main challenges in ETPA design lies in accommodating wide modulation bandwidths. Adaptive de-troughing, a digital signal processing approach for extending the modulation bandwidth capability of an existing dynamic power supply, is described and evaluated. Measurements demonstrated the ability to extend ET operation to 20 MHz LTE signals. In addition, ~5-6% modulator efficiency enhancement was measured when comparing "standard" to "adaptive" de-troughing supply waveforms.
Book Synopsis Development of High Efficiency Power Amplifiers for Emerging Wireless Applications by : Jeffery Alan Curtis
Download or read book Development of High Efficiency Power Amplifiers for Emerging Wireless Applications written by Jeffery Alan Curtis and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Ph.D. research, several Ka-Band power amplifiers are designed and built for use in next generation mobile broadband communication systems. The Doherty power amplifier architecture is demonstrated as a possible solution to improving the back-off efficiency of millimeter-wave power amplifiers, since many mobile broadband communication systems employ modulation formats with large peak-to-average power ratios. This research also demonstrates some novel techniques to improve upon the Doherty architecture for millimeter-wave power amplifier design. Two fully integrated Ka-Band Doherty power amplifiers are designed and developed using a 0.15-[mu]m GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The first uses the classic Doherty configuration with some previously developed modifications to resolve some practical issues and achieves a measured small signal gain of 10.3 dB, measured output power at 1-dB compression point (P1dB) of 25.1 dBm, measured peak power added efficiency (PAE) of 38%, and measured PAE of 27% at 6-dB back-off power. The bias network of this same Doherty was then modified by short circuiting some resistors in the gate bias path and it then achieves a measured small signal gain of 10.5 dB, measured output power at 1-dB compression point (P1dB) of 26.9 dBm, measured peak power added efficiency of 42%, and measured PAE of 32% at 6-dB back-off power. The second Doherty amplifier uses a novel load-pull based Doherty technique accounting for nonideal back-off impedance in millimeter-wave power amplifiers and achieves a measured small signal gain of 9 dB, simulated output power at 1-dB compression point (P1dB) of 29 dBm, simulated peak power added efficiency of 46%, and simulated PAE of 35% at 6-dB back-off power. The performance achieved with these power amplifiers makes them a promising candidate for use in next generation mobile broadband communication systems.
Book Synopsis GaN Transistors for Efficient Power Conversion by : Alex Lidow
Download or read book GaN Transistors for Efficient Power Conversion written by Alex Lidow and published by John Wiley & Sons. This book was released on 2014-09-15 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium nitride (GaN) is an emerging technology that promises to displace silicon MOSFETs in the next generation of power transistors. As silicon approaches its performance limits, GaN devices offer superior conductivity and switching characteristics, allowing designers to greatly reduce system power losses, size, weight, and cost. This timely second edition has been substantially expanded to keep students and practicing power conversion engineers ahead of the learning curve in GaN technology advancements. Acknowledging that GaN transistors are not one-to-one replacements for the current MOSFET technology, this book serves as a practical guide for understanding basic GaN transistor construction, characteristics, and applications. Included are discussions on the fundamental physics of these power semiconductors, layout and other circuit design considerations, as well as specific application examples demonstrating design techniques when employing GaN devices. With higher-frequency switching capabilities, GaN devices offer the chance to increase efficiency in existing applications such as DC–DC conversion, while opening possibilities for new applications including wireless power transfer and envelope tracking. This book is an essential learning tool and reference guide to enable power conversion engineers to design energy-efficient, smaller and more cost-effective products using GaN transistors. Key features: Written by leaders in the power semiconductor field and industry pioneers in GaN power transistor technology and applications. Contains useful discussions on device–circuit interactions, which are highly valuable since the new and high performance GaN power transistors require thoughtfully designed drive/control circuits in order to fully achieve their performance potential. Features practical guidance on formulating specific circuit designs when constructing power conversion systems using GaN transistors – see companion website for further details. A valuable learning resource for professional engineers and systems designers needing to fully understand new devices as well as electrical engineering students.
Book Synopsis Development of High Efficiency and High Linearity Power Amplifiers by : Mohamed Magdi Ahmed Darwish
Download or read book Development of High Efficiency and High Linearity Power Amplifiers written by Mohamed Magdi Ahmed Darwish and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Power amplifiers typically dominate transmitter and system characteristics. They have the highest DC power consumption, power dissipation, and heat dissipation. Power MMICs have the largest chip area which means higher cost. Modern communication digital modulation techniques require that PAs should have high linear characteristics. On the other hand, PAs are required to be efficient to decrease power consumption and to extend the operation life of battery operated devices. Gallium Nitride PAs became the focus of industry in the last decade. They provide the highest power density among other technologies, as well as providing high efficiency and are suitable for wide bandwidth applications. On the other hand, they suffer from soft compression, AM/AM and AM/PM distortions at higher levels compared to GaAs and Si based devices. Also, since GaN is considered a new technology power gain decreases for mm-wave frequencies. In this Ph.D. research, we address 3 problems: linearity, efficiency and gain of mm-wave power amplifiers. We present 4 contributions; First, we demonstrate the design of a linear and high efficient power amplifier (PA) by using different gate bias voltages for parallelly combined Gallium Nitride (GaN) high electron mobility transistors (HEMTs). The experimental results show that the linearized PA achieves the gain flatness of 0.3 dB over a 35 dB power range and has a measured sharp output power at 1 dB compression point (P1dB) of 38.5 dBm, less than 2 dB below the saturated power (P[subscript SAT]). The measured adjacent channel power ratio (ACPR) of the proposed linearized PA shows up to 8 dB improvements over the PA biased ~ class A (47% Idss) Second, we propose a new modulating load range for a Doherty power amplifier (DPA) that will maintain maximum drain voltage swing and consequently peak efficiency in over 6-dB power back-off (PBO). At 6-dB PBO, the real part of the new modulating load seen by the main amplifier is less than 2*R[subscript opt]. The new load range allows for the design of a compact, low loss output matching and combiner circuit and a simple single drain bias line for the main and auxiliary amplifiers. The proposed 2-stage DPA using the new modulating loads is designed at 15 GHZ in a 0.15 [mu]m enhancement mode (E-mode) Gallium Arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) process. The proposed DPA achieves a measured P[subscript sat] of 27 dBm, a peak power added efficiency (PAE) of 41% and a PAE of 34% at 6 dB PBO with a gain of 17 dB. Third, we propose an extended range Doherty power amplifier (DPA) to achieve high efficiency at 9-dB power back-off (PBO) using a novel loading impedance range. The proposed loading impedance range enables the auxiliary transistor to deliver more current so that symmetric devices can be used in the DPA and results in a compact and low loss output combining circuit. A 20-Watt DPA using Gallium nitride high electron mobility transistors (GaN HEMTs) at 3.5 GHz has been developed to demonstrate the concept. Measurements show power added efficiency (PAE) of 69% at 42.9 dBm saturation output power, PAE of 55% at 9-dB PBO, and gain of 12 dB. We believe our proposed DPA has the highest 9-dB PBO PAE of 55% among reported GaN DPA’s. Finally, we introduce an inductive feedback technique to enhance the gain of mm-wave power amplifiers. A 3-stage 60 GHz PA was designed with 22 dB gain and output power of almost 1-watt.
Book Synopsis High Efficiency RF and Microwave Solid State Power Amplifiers by : Paolo Colantonio
Download or read book High Efficiency RF and Microwave Solid State Power Amplifiers written by Paolo Colantonio and published by John Wiley & Sons. This book was released on 2009-07-08 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Do you want to know how to design high efficiency RF and microwave solid state power amplifiers? Read this book to learn the main concepts that are fundamental for optimum amplifier design. Practical design techniques are set out, stating the pros and cons for each method presented in this text. In addition to novel theoretical discussion and workable guidelines, you will find helpful running examples and case studies that demonstrate the key issues involved in power amplifier (PA) design flow. Highlights include: Clarification of topics which are often misunderstood and misused, such as bias classes and PA nomenclatures. The consideration of both hybrid and monolithic microwave integrated circuits (MMICs). Discussions of switch-mode and current-mode PA design approaches and an explanation of the differences. Coverage of the linearity issue in PA design at circuit level, with advice on low distortion power stages. Analysis of the hot topic of Doherty amplifier design, plus a description of advanced techniques based on multi-way and multi-stage architecture solutions. High Efficiency RF and Microwave Solid State Power Amplifiers is: an ideal tutorial for MSc and postgraduate students taking courses in microwave electronics and solid state circuit/device design; a useful reference text for practising electronic engineers and researchers in the field of PA design and microwave and RF engineering. With its unique unified vision of solid state amplifiers, you won’t find a more comprehensive publication on the topic.
Book Synopsis Design of a Power Amplifier and Envelope Amplifier for a Multi-band Multi-standard Envelope Tracking System by : Yushi Hu
Download or read book Design of a Power Amplifier and Envelope Amplifier for a Multi-band Multi-standard Envelope Tracking System written by Yushi Hu and published by . This book was released on 2012 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the design of a Power Amplifier (PA) and envelope amplifier for an Envelope Tracking (ET) system that is aimed at meeting emerging radio standards in terms of power efficiency and linearity. The class J mode of operation, as well as the efficiency and power contours from load pull was exploited to develop an adequate procedure for the design of a broadband and high efficiency radio frequency PA. An in-depth study has also been conducted for a hybrid envelope amplifier topology in order to optimize it for power efficiency through proper setting of its switching stage supply. Two separate proof of concept prototypes of the PA and envelop amplifier were designed, fabricated and tested. The PA designed was able to achieve an average drain efficiency of 73.6%, average output power of 45.89dBm, and an average gain of 18dB between 650MHz and 1.050GHz (48% bandwidth). The envelope amplifier achieved close to 74.6% efficiency for a 5MHz bandwidth LTE signal envelope with 6.4dB peak to average power ratio.
Book Synopsis Bandwidth and Efficiency Enhancement in Radio Frequency Power Amplifiers for Wireless Transmitters by : Karun Rawat
Download or read book Bandwidth and Efficiency Enhancement in Radio Frequency Power Amplifiers for Wireless Transmitters written by Karun Rawat and published by Springer Nature. This book was released on 2020-03-05 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on broadband power amplifier design for wireless communication. Nonlinear model embedding is described as a powerful tool for designing broadband continuous Class-J and continuous class F power amplifiers. The authors also discuss various techniques for extending bandwidth of load modulation based power amplifiers, such as Doherty power amplifier and Chireix outphasing amplifiers. The book also covers recent trends on digital as well as analog techniques to enhance bandwidth and linearity in wireless transmitters. Presents latest trends in designing broadband power amplifiers; Covers latest techniques for using nonlinear model embedding in designing power amplifiers based on waveform engineering; Describes the latest techniques for extending bandwidth of load modulation based power amplifiers such as Doherty power amplifier and Chireix outphasing amplifiers; Includes coverage of hybrid analog/digital predistortion as wideband solution for wireless transmitters; Discusses recent trends on on-chip power amplifier design with GaN /GaAs MMICs for high frequency applications.
Book Synopsis High Efficiency Power Amplifier Design for 28 GHz 5G Transmitters by : Nourhan Elsayed
Download or read book High Efficiency Power Amplifier Design for 28 GHz 5G Transmitters written by Nourhan Elsayed and published by Springer Nature. This book was released on 2022-02-02 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces power amplifier design in 22nm FDSOI CMOS dedicated towards 5G applications at 28 GHz and presents 4 state-of-the-art power amplifier designs. The authors discuss power amplifier performance metrics, design trade-offs, and presents different power amplifier classes utilizing efficiency enhancement techniques at 28 GHz. The book presents the design process from theory, simulation, layout, and finally measurement results.
Book Synopsis High-Efficiency Load Modulation Power Amplifiers for Wireless Communications by : Zhancang Wang
Download or read book High-Efficiency Load Modulation Power Amplifiers for Wireless Communications written by Zhancang Wang and published by Artech House. This book was released on 2017-06-30 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge resource presents a complete and systematic overview of the practical design considerations of radio frequency (RF) high efficiency load modulation power amplifiers (PA) for modern wireless communications for 4G and beyond. It provides comprehensive insight into all aspects of load modulation PA design and optimization not only covering design approaches specifically for passive and active load modulation operation but also hybrid with dynamic supply modulation and digital signal processing algorithms required for performance enhancement. Passive load impedance tuner design, dynamic load modulation PA, active load modulation PA and Doherty PA design for efficiently enhancement are explained. Readers find practical guidance into load modulation PA design for bandwidth extension, including video bandwidth enhancement techniques, broadband dynamic load amplifiers, topology selection, design procedures, and network output. This book presents the evolution and integration of classical load modulation PA topologies in order to meet new challenges in the field.
Book Synopsis Envelope Amplifier for Broadband Base-station Envelope Tracking Power Amplifier by : Qiuyao Zhu
Download or read book Envelope Amplifier for Broadband Base-station Envelope Tracking Power Amplifier written by Qiuyao Zhu and published by . This book was released on 2011 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Envelope tracking (ET), which is a dynamic supply control technology to realize high efficiency power amplifiers, is a promising approach for base-station transmitters of the future. The envelope amplifier (EA) in ET systems provides a non-constant modulated power supply to the RF transistor. It is challenging to design so that it is both broadband and high efficiency, while meeting the stringent linearity requirements for high peak-to-average ratio signals in modern wireless communication systems. This thesis focuses on EA design and implementation for efficiency enhancement of ET systems with broadband envelope input signals. First, the ET system architecture is analyzed, and the efficiencies of RF transistors and envelope amplifiers are described. Secondly, the principles of the EA operation are investigated, and each circuit stage is carefully designed for broadband signals. Then, an EA model, including the RF transistor load, is developed in PSpice, and many simulations are described in order to better analyze and design the broadband EA for high efficiency. After the design, a broadband EA is implemented on a PCB board. The testing with constant resistive loads is carried out to verify the function and measure the efficiencies of 5 MHz WCDMA and 20 MHz LTE-A downlink envelope signals. Finally, tests on the whole ET system are performed, and the overall drain and power added efficiencies are tabulated. For this broadband envelope amplifier, the efficiency for a 5 MHz WCDMA input signal is above 75%, and for 20 MHz LTE-A, it works robustly with an efficiency of 62%.
Book Synopsis RF and Microwave Power Amplifier Design by : Andrei Grebennikov
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.
