High Slew-rate Adaptive Biasing Hybrid Envelope Tracking Supply Modulator for LTE Applications
High Slew-rate Adaptive Biasing Hybrid Envelope Tracking Supply Modulator for LTE Applications

Author: Yue Jing

Publisher:

Published: 2017

Total Pages: 58

ISBN-13:

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As 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.

Hybrid Envelope Tracking Supply Modulator Analysis and Design for Wideband Applications
Hybrid Envelope Tracking Supply Modulator Analysis and Design for Wideband Applications

Author: Parisa Mahmoudidaryan

Publisher:

Published: 2019

Total Pages: 55

ISBN-13:

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A wideband hybrid envelope tracking modulator utilizing a hysteretic-controlled three-level switching converter and a slew-rate enhanced linear amplifierer is presented. In addition to smaller ripple and lower losses of three-level switching converters, employing the proposed hysteresis control loop results in a higher speed loop and wider bandwidth converter, enabling over 80MHz of switching frequency. A concurrent sensor circuit monitors and regulates the flying capacitor voltage VCF and eliminates conventional required calibration loop to control it. The hysteretic-controlled three-level switching converter provides a high percentage of power amplifier supply load current with lower ripple, reducing the linear amplifier high-frequency current and ripple cancellation current, improving the overall system efficiency. A slew-rate enhancement (SRE) circuit is employed in the linear amplifier resulting in slew-rate of

Technologies Enabling Future Mobile Connectivity & Sensing
Technologies Enabling Future Mobile Connectivity & Sensing

Author: François Brunier

Publisher: CRC Press

Published: 2024-01-09

Total Pages: 194

ISBN-13: 1003812260

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In today’s connected world, the demand for mobile communications and instant access to information, anytime and anywhere, has drastically changed the electronics landscape, both consumer and industrial. Novel 5G and 6G systems will enable connectivity in all forms between humans, devices, machines, and any objects. They will provide virtually ubiquitous, ultra-high bandwidth and low latency network access to individual users, as well as to all objects benefiting from being connected. They will be the "eyes and ears" of Artificial Intelligence systems as it will provide real-time data collection and analysis. Such diversity calls for a new paradigm in terms of flexibility, not only related to performance, but also in terms of scalability and cost. 5G and 6G communication systems imply a major stake of sovereignty and autonomy for the communication sector and digital infrastructures of the future. All products related to IoT, traffic, and health care, supported by connectivity will benefit the citizens in their daily lives to improve everything from business to private affairs. Together, this will influence society as much as smart phones did in the recent past. It is all about communication and connectivity. This book provides an overview of the latest research results in this field. It is based on the close collaboration in the BEYOND5 project, extended with vision and roadmap insights by European experts leading the 6G development. The BEYOND5 project has built a completely European supply chain for Radio-Frequency Electronics, enabling new RF domains for sensing, communication, 5G radio infrastructure and beyond. Moving forward into higher frequency bands above 100 GHz for 6G, also more disruptive technologies, using heterogeneous integration of CMOS, SOI, and III/V components such as GaN or InP, and advanced packaging techniques will be necessary to realize the objectives of ubiquitous, ultra-high bandwidth and low latency networks. The book bundles the scientific content of the International Workshop on "Technologies enabling future mobile connectivity & sensing" in Lisbon, Portugal 10 September 2023, as part of the ESSCIRC/ESSDERC 2023 European Solid-state Circuits and Devices Conference. Through articles and abstracts, a combined view of experts and practitioners representing academia, research, and industry in the field of wireless communication systems is given. They cover the topics of RF and digital SOI technology development for 5 and 6G, device and substrate characterization, packaging technology, and the realization of full systems including power amplifiers, linearization techniques, beamforming transceivers, access points, and radar detection.

GaN Transistors for Efficient Power Conversion
GaN Transistors for Efficient Power Conversion

Author: Alex Lidow

Publisher: John Wiley & Sons

Published: 2019-09-30

Total Pages: 389

ISBN-13: 1119594146

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An up-to-date, practical guide on upgrading from silicon to GaN, and how to use GaN transistors in power conversion systems design This updated, third edition of a popular book on GaN transistors for efficient power conversion 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. GaN Transistors for Efficient Power Conversion, 3rd Edition brings key updates to the chapters of Driving GaN Transistors; Modeling, Simulation, and Measurement of GaN Transistors; DC-DC Power Conversion; Envelope Tracking; and Highly Resonant Wireless Energy Transfer. It also offers new chapters on Thermal Management, Multilevel Converters, and Lidar, and revises many others throughout. Written by leaders in the power semiconductor field and industry pioneers in GaN power transistor technology and applications Updated with 35% new material, including three new chapters on Thermal Management, Multilevel Converters, Wireless Power, and Lidar Features practical guidance on formulating specific circuit designs when constructing power conversion systems using GaN transistors A valuable resource for professional engineers, systems designers, and electrical engineering students who need to fully understand the state-of-the-art GaN Transistors for Efficient Power Conversion, 3rd Edition is an essential learning tool and reference guide that enables power conversion engineers to design energy-efficient, smaller, and more cost-effective products using GaN transistors.

Envelope Tracking Supply Modulator with Trellis Search-Based Switching and 160 MHz Capability
Envelope Tracking Supply Modulator with Trellis Search-Based Switching and 160 MHz Capability

Author: Weiyu Leng

Publisher:

Published: 2020

Total Pages: 156

ISBN-13:

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Envelope tracking is widely used to raise the efficiency of PAs. An envelope tracking supply modulator (ETSM) modulates PA's supply voltage to tracks the RF waveform's envelope, so that the PA will operate in saturation all the time. A hybrid amplifier is commonly used to realize the ETSM, which, in effect, partitions the envelope bandwidth into a low and high subband. An efficient switching buck converter tracks the low band. In parallel with it, an op-amp supplies the current in the high band. In prior arts, the hybrid amplifier is realized with feedback using a hysteresis comparator, whose output actuates the buck converter to respond to the changing envelope; the continuous-time op-amp makes up for the error. But a comparator-driven buck converter produces a slew-rate limited current that always lags the envelope waveform. This forces the op-amp to produce a larger current to correct the error, and the arrangement cannot guarantee that the buck converter switches no often than is absolutely necessary. We replace the hysteresis comparator with a novel trellis-search that, first, finds the optimal sequence to switch the buck converter to minimize the RMS current that the op-amp must deliver; second, to lower the loss from switching the capacitance of FETs, it penalizes a large number of switching events in the buck converter. Meanwhile, with a conventional on-chip hysteresis comparator, we can demonstrate ETSM operation up to 160 MHz modulation bandwidth. This is the widest bandwidth reported so far for any ETSM.