High Efficiency Broadband Envelope Tracking Power Amplifiers

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High Efficiency Broadband Envelope-Tracking Power Amplifiers

Author : Jonmei Johana Yan
Publisher :
ISBN 13 : 9781303195266
Total Pages : 168 pages
Book Rating : 4.1/5 (952 download)

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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.

Envelope Tracking Power Amplifiers for Wireless Communications

Author : Zhancang Wang
Publisher : Artech House
ISBN 13 : 1608077845
Total Pages : 363 pages
Book Rating : 4.6/5 (8 download)

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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.

Envelope Amplifier for Broadband Base-station Envelope Tracking Power Amplifier

Author : Qiuyao Zhu
Publisher :
ISBN 13 : 9781124727844
Total Pages : 125 pages
Book Rating : 4.7/5 (278 download)

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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%.

High Efficiency Wideband Envelope Tracking Power Amplifier for Next-generation Wireless Communications

Author : Myoungbo Kwak
Publisher :
ISBN 13 : 9781124856230
Total Pages : 109 pages
Book Rating : 4.8/5 (562 download)

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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.

High Efficiency Linear Envelope Tracking and Envelope Elimination and Restoration Power Amplifier for WLAN OFDM Applications

Author : Feipeng Wang
Publisher :
ISBN 13 :
Total Pages : 131 pages
Book Rating : 4.:/5 (819 download)

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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.

High-Efficiency Load Modulation Power Amplifiers for Wireless Communications

Author : Zhancang Wang
Publisher : Artech House
ISBN 13 : 1630814679
Total Pages : 389 pages
Book Rating : 4.6/5 (38 download)

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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.

Wideband High Efficiency CMOS Envelope Amplifiers for 4G LTE Handset Envelope Tracking RF Power Amplifiers

Author : Muhammad Hassan
Publisher :
ISBN 13 : 9781267434951
Total Pages : 124 pages
Book Rating : 4.4/5 (349 download)

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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.

Bandwidth and Efficiency Enhancement in Radio Frequency Power Amplifiers for Wireless Transmitters

Author : Karun Rawat
Publisher : Springer Nature
ISBN 13 : 3030388662
Total Pages : 390 pages
Book Rating : 4.0/5 (33 download)

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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.

Development of a High-efficiency Power Amplifier for Envelope Tracking Applications

Author : Zulhazmi Bin A. Mokhti
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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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:

Design of a Power Amplifier and Envelope Amplifier for a Multi-band Multi-standard Envelope Tracking System

Author : Yushi Hu
Publisher :
ISBN 13 :
Total Pages : 61 pages
Book Rating : 4.:/5 (835 download)

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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.

Envelope Amplifier Design for Wireless Base-station Power Amplifiers

Author : Chin Hsia
Publisher :
ISBN 13 : 9781124324258
Total Pages : 128 pages
Book Rating : 4.3/5 (242 download)

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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.

Dynamic Power Supply Transmitters

Author : Earl McCune
Publisher : Cambridge University Press
ISBN 13 : 1107059178
Total Pages : 495 pages
Book Rating : 4.1/5 (7 download)

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Book Synopsis Dynamic Power Supply Transmitters by : Earl McCune

Download or read book Dynamic Power Supply Transmitters written by Earl McCune and published by Cambridge University Press. This book was released on 2015-05-21 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Power is dissipated (lost) when this current flows through any resistance, which includes the amplifier's transistor. This dissipated power is the product of the current in the load times the voltage difference between the supply voltage to the amplifier and the output signal voltage. When the voltage supplied to the amplifier is a constant value, and by far the most common design practice, the situation in Fig. 1-2a results. Power dissipation in the amplifier is maximum when the output signal voltage is 1/2 of the supply voltage. When the output signal voltage is higher, even though the current value is larger the voltage drop is less and the power dissipation is lower. Similarly, when the output signal voltage is small, even though the voltage drop is now large the current in the load is smaller and again the power dissipation is lower"--

Broadband Power Amplifier Design with High Power, High Efficiency and Large Back-off Range

Author : Yuchen Cao
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (136 download)

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Book Synopsis Broadband Power Amplifier Design with High Power, High Efficiency and Large Back-off Range by : Yuchen Cao

Download or read book Broadband Power Amplifier Design with High Power, High Efficiency and Large Back-off Range written by Yuchen Cao and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As modern communication system technology develops, the demand for devices with smaller size, higher efficiency, and larger bandwidth has increased dramatically. To achieve this purpose, a novel architecture of load modulated balanced amplifier (LMBA) with a unique load-modulation characteristic different from any existing LMBAs and Doherty power amplifiers (DPAs) was presented, which is named as Pseudo-Doherty LMBA (PD-LMBA). Based on a special combination of control amplifier (carrier) and balanced amplifier (peaking) together with proper phase and amplitude controls, an optimal load-modulation behavior can be achieved for PD-LMBA leading to maximized efficiency over extended power back-off range. More importantly, the efficiency optimization can be achieved with only a static setting of phase offset at a given frequency, which greatly simplifies the complexity for phase control. Furthermore, the co-operations of the carrier and peaking amplifiers in PD-LMBA are fully de-coupled, thus lifting the fundamental bandwidth barrier imposed on Doherty-based active load modulation.

Concurrent Multi-band Envelope Tracking Power Amplifiers for Emerging Wireless Communications

Author : Hassan Sarbishaei
Publisher :
ISBN 13 :
Total Pages : 112 pages
Book Rating : 4.:/5 (96 download)

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Book Synopsis Concurrent Multi-band Envelope Tracking Power Amplifiers for Emerging Wireless Communications by : Hassan Sarbishaei

Download or read book Concurrent Multi-band Envelope Tracking Power Amplifiers for Emerging Wireless Communications written by Hassan Sarbishaei and published by . This book was released on 2014 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wireless communication is shifting toward data-centric broadband services, resulting in employment of sophisticated and spectrum efficient modulation and access techniques. This yields communication signals with large peak-to-average power ratios (PAPR) and stringent linearity requirements. For example, future wireless communication standard, such as long term evolution advanced (LTE-A) require adoption of carrier aggregation techniques to improve their effective modulation bandwidth. The carrier aggregation technique for LTE-A incorporates multiple carriers over a wide frequency range to create a wider bandwidth of up to 100MHz. This will require future power amplifiers (PAs) and transmitters to efficiently amplify concurrent multi-band signals with large PAPR, while maintaining good linearity. Different back-off efficiency enhancement techniques are available, such as envelope tracking (ET) and Doherty. ET has gained a lot of attention recently as it can be applied to both base station and mobile transmitters. Unfortunately, few publications have investigated concurrent multi-band amplification using ET PAs, mainly due to the limited bandwidth of the envelope amplifier. In this thesis, a novel approach to enable concurrent amplification of multi-band signals using a single ET PA will be presented. This thesis begins by studying the sources of nonlinearities in single-band and dual-band PAs. Based on the analysis, a design methodology is proposed to reduce the sources of memory effects in single-band and dual-band PAs from the circuit design stage and improve their linearizability. Using the proposed design methodology, a 45W GaN PA was designed. The PA was linearized using easy to implement, memoryless digital pre-distortion (DPD) with 8 and 28 coefficients when driven with single-band and dual-band signals, respectively. This analysis and design methodology will enable the design of PAs with reduced memory effects, which can be linearized using simple, power efficient linearization techniques, such as lookup table or memoryless polynomial DPD. Note that the power dissipation of the linearization engine becomes crucial as we move toward smaller base station cells, such as femto- and pico-cells, where complicated DPD models cannot be implemented due to their significant power overhead. This analysis is also very important when implementing a multi-band ET PA system, where the sources of memory effects in the PA itself are minimized through the proposed design methodology. Next, the principle of concurrent dual-band ET operation using the low frequency component (LFC) of the envelope of the dual-band signal is presented. The proposed dual-band ET PA modulates the drain voltage of the PA using the LFC of the envelope of the dual-band signal. This will enable concurrent dual-band operation of the ET PA without posing extra bandwidth requirements on the envelope amplifier. A detailed efficiency and linearity analysis of the dual-band ET PA is also presented. Furthermore, a new dual-band DPD model with supply dependency is proposed in this thesis, capable of capturing and compensating for the sources of distortion in the dual-band ET PA. To the best of our knowledge, concurrent dual-band operation of ET PAs using the LFC of the envelope of the dual-band signal is presented for the first time in the literature. The proposed dual-band ET operation is validated using the measurement results of two GaN ET PA prototypes. Lastly, the principle of concurrent dual-band ET operation is extended to multi-band signals using the LFC of the envelope of the multi-band signal. The proposed multi-band ET operation is validated using the measurement results of a tri-band ET PA. To the best of our knowledge, this is the first reported tri-band ET PA in literature. The tri-band ET PA is linearized using a new tri-band DPD model with supply dependency.

Design of High Efficiency Broadband Adjusted Class AB Power Amplifier

Author : Aynaz Vatankhahghadim
Publisher :
ISBN 13 :
Total Pages : 60 pages
Book Rating : 4.:/5 (827 download)

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Book Synopsis Design of High Efficiency Broadband Adjusted Class AB Power Amplifier by : Aynaz Vatankhahghadim

Download or read book Design of High Efficiency Broadband Adjusted Class AB Power Amplifier written by Aynaz Vatankhahghadim and published by . This book was released on 2010 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis starts with a discussion of different classes of operation of power amplifiers (PAs). Comparing advantages and disadvantages of these classes, class AB is chosen as the best initial candidate for the design of broadband PA. Different methods for design of matching networks are first discussed. Some of them fall into the group of narrowband matching networks, while others are suitable for a broadband context. Broadband design methodologies are categorized into two groups of real-to-real transformations and complex-to-real transformations. Complex-to-real transformations are the most useful methods for this project, since design of power amplifiers deals with complex loads rather than just real loads. The design of broadband matching networks exploiting filter theory is presented in this thesis for synthesizing broadband and highly efficient power amplifiers (PAs). Starting with sets of optimum impedances over the targeted frequency band, the matching networks are designed using a systematic approach. The effects of load termination at the 2nd and 3rd harmonic on the PA performance (efficiency) are studied. The significance of proper termination, especially at the 2nd harmonic, is highlighted. To prevent further complication of the design process, though, specific harmonic termination (stubs) is avoided and special arrangement of the matching network (position of the bias network) is preferred, as it is found to lead to acceptable efficiency. Two PA prototypes were designed with the proposed methodology using 25W GaN devices. The designs targeted two frequency bands: 1.8 to 2.2 GHz (20% BW) and 1.8 to 2.7 GHz (40% BW). For the former, drain efficiency (DE) of 70% (+/-5%) and output power of 45.5 dBm (+/- 1.0dB) was measured while the latter achieved very promising efficiency of about 60% over the entire bandwidth.

Linear CMOS RF Power Amplifiers

Author : Hector Solar Ruiz
Publisher : Springer Science & Business Media
ISBN 13 : 1461486572
Total Pages : 191 pages
Book Rating : 4.4/5 (614 download)

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Book Synopsis Linear CMOS RF Power Amplifiers by : Hector Solar Ruiz

Download or read book Linear CMOS RF Power Amplifiers written by Hector Solar Ruiz and published by Springer Science & Business Media. This book was released on 2013-09-14 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work establishes the design flow for the optimization of linear CMOS power amplifiers from the first steps of the design to the final IC implementation and tests. The authors also focuses on design guidelines of the inductor’s geometrical characteristics for power applications and covers their measurement and characterization. Additionally, a model is proposed which would facilitate designs in terms of transistor sizing, required inductor quality factors or minimum supply voltage. The model considers limitations that CMOS processes can impose on implementation. The book also provides different techniques and architectures that allow for optimization.

The Auxiliary Envelope Tracking RF Power Amplifier System

Author : Zubaida Yusoff
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (835 download)

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Book Synopsis The Auxiliary Envelope Tracking RF Power Amplifier System by : Zubaida Yusoff

Download or read book The Auxiliary Envelope Tracking RF Power Amplifier System written by Zubaida Yusoff and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The advancement of the mobile communication industry increases the need for RF power amplifier (RFPA) to be more efficient and linear. The communication network that is shifting towards smaller micro-cell or nano-cell network has also motivated the design of the RF power amplifier to be simple, compact and cost efficient. In this research work, a novel technique for efficiency and linearity improvement of the RFPA is presented. A simplistic approach in the technique called 'Auxiliary Envelope Tracking' (AET) system has promoted the design for small and straightforward AET tracking generator, a key component in the system. The use of low cost components in the AET tracking generator has made the technique commercially attractive. The AET technique proposes a separation in generating DC and AC components of the AET signal that biases the drain of the RFPA. The separation eases the generation of the signals resulting in low power consumption that leads to efficiency improvement. The investigation of the gain characteristic of gallium nitride (GaN) RFPA has shown an important RFPA attribute where the gain varied substantially as the drain voltage increases. By using the AET technique, the gain characteristic is harnessed to get linearity improvement. In order to validate the technique, AET measurement systems for two-carrier and WCDMA signals were developed and experimented. A special Class AB RFPA is designed and implemented to use dedicatedly for this investigation. In two-carrier signal measurement, a tracking generator is developed that consists of an envelope amplifier (EA) and a diplexer. The RFPA and the tracking generator are then combined to be an integrated AET block. In order to accommodate the high peak-toaverage ratio (PAR) and high bandwidth WCDMA signal, a broadband RF transformer was designed as part of the AET tracking generator to replace the diplexer. The two-carrier and WCDMA signals measurement results have proven that the AET technique is a valid technique for efficiency and linearity improvement. The improvements were achieved with simple, compact and cost-effective implementation.