Highly Efficient Envelope Tracking Modulator for Wireless Communication
Author: 簡子皓
Publisher:
Published: 2020
Total Pages:
ISBN-13:
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Envelope Tracking Power Amplifiers for Wireless Communications
Author: Zhancang Wang
Publisher: Artech House
Published: 2014-06-01
Total Pages: 363
ISBN-13: 1608077845
DOWNLOAD EBOOKEnvelope 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.
High Efficiency Broadband Envelope-Tracking Power Amplifiers
Author: Jonmei Johana Yan
Publisher:
Published: 2013
Total Pages: 168
ISBN-13: 9781303195266
DOWNLOAD EBOOKIn 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.
High-Efficiency Load Modulation Power Amplifiers for Wireless Communications
Author: Zhancang Wang
Publisher: Artech House
Published: 2017-06-30
Total Pages: 389
ISBN-13: 1630814679
DOWNLOAD EBOOKThis 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.
High Slew-rate Adaptive Biasing Hybrid Envelope Tracking Supply Modulator for LTE Applications
Author: Yue Jing
Publisher:
Published: 2017
Total Pages: 58
ISBN-13:
DOWNLOAD EBOOKAs wireless communication enters smartphone era, more complicated communication technologies are being used to transmit higher data rate. Power amplifier (PA) has to work in back-off region, while this inevitably reduces battery life for cellphones. Various techniques have been reported to increase PA efficiency, such as envelope elimination and restoration (EER) and envelope tracking (ET). However, state of the art ET supply modulators failed to address high efficiency, high slew rate, and accurate tracking concurrently. In this dissertation, a linear-switch mode hybrid ET supply modulator utilizing adaptive biasing and gain enhanced current mirror operational transconductance amplifier (OTA) with class-AB output stage in parallel with a switching regulator is presented. In comparison to a conventional OTA design with similar quiescent current consumption, proposed approach improves positive and negative slew rate from 50 V/μs to 93.4 V/μs and -87 V/μs to -152.5 V/μs respectively, dc gain from 45 dB to 67 dB while consuming same amount of quiescent current. The proposed hybrid supply modulator achieves 83% peak efficiency, power added efficiency (PAE) of 42.3% at 26.2 dBm for a 10 MHz 7.24 dB peak-to-average power ratio (PAPR) LTE signal and improves PAE by 8% at 6 dB back off from 26.2 dBm power amplifier (PA) output power with respect to fixed supply. With a 10 MHz 7.24 dB PAPR QPSK LTE signal the ET PA system achieves adjacent channel leakage ratio (ACLR) of -37.7 dBc and error vector magnitude (EVM) of 4.5% at 26.2 dBm PA output power, while with a 10 MHz 8.15 dB PAPR 64QAM LTE signal the ET PA system achieves ACLR of -35.6 dBc and EVM of 6% at 26 dBm PA output power without digital pre-distortion (DPD). The proposed supply modulator core circuit occupies 1.1 mm2 die area, and is fabricated in a 0.18 μm CMOS technology.
Design of the Envelope Tracking Hybrid Supply Modulator for Power Amplifier in LTE-20MHz Wireless Communication Applications
Author: 鄧厚威
Publisher:
Published: 2022
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKRecent Technical Developments in Energy-Efficient 5G Mobile Cells
Author: Raed A. Abd-Alhameed
Publisher: MDPI
Published: 2020-06-17
Total Pages: 292
ISBN-13: 3039362127
DOWNLOAD EBOOKThis 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)).
Circuits and Systems for Future Generations of Wireless Communications
Author: Aleksandar Tasic
Publisher: Springer Science & Business Media
Published: 2009-05-16
Total Pages: 308
ISBN-13: 1402099177
DOWNLOAD EBOOKThe idea for this book originated from a Special Session on Circuits and Systems for Future Generations of Wireless Communications that was presented at the 2005 InternationalSymposiumon Circuits and Systems, which was then followed by two Special Issues bearing the same title that appeared in the March and April 2008 issues of the IEEE Transactions on Circuits and Systems – Part II: Express Briefs. Out of a large number of great contributions, we have selected those tting best the book format based on their quality. We would like to thank all the authors, the reviewers of the Transactions on Circuits and Systems – Part II, and the reviewers of the nal book material for their efforts in creating this manuscript. We also thank the Springer Editorial Staff for their support in putting together all the good work. We hope that this book will provide you, the reader, with new insights into Circuits and Systems for Future Generations of Wireless Communications.
GaN Transistors for Efficient Power Conversion
Author: Alex Lidow
Publisher: John Wiley & Sons
Published: 2014-09-15
Total Pages: 266
ISBN-13: 1118844769
DOWNLOAD EBOOKGallium 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.
Analog Circuit Design
Author: Michiel Steyaert
Publisher: Springer Science & Business Media
Published: 2008-09-19
Total Pages: 361
ISBN-13: 1402089449
DOWNLOAD EBOOKAnalog Circuit Design contains the contribution of 18 tutorials of the 17th workshop on Advances in Analog Circuit Design. Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art information is shared and overviewed. This book is number 17 in this successful series of Analog Circuit Design.
