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Author

Yan Li

Other affiliations: RF Micro Devices
Bio: Yan Li is an academic researcher from Texas Tech University. The author has contributed to research in topics: Amplifier & Cascode. The author has an hindex of 13, co-authored 38 publications receiving 760 citations. Previous affiliations of Yan Li include RF Micro Devices.
Topics: Amplifier, Cascode, BiCMOS, Predistortion, CMOS

Papers
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Journal ArticleDOI
Yan Li1, Jerry Lopez1, Po-Hsing Wu1, Weibo Hu1, Ruili Wu1, Donald Y.C. Lie1 
TL;DR: In this article, a SiGe envelope tracking (ET) cascode power amplifier with an integrated CMOS envelope modulator for mobile WiMAX and 3GPP long-term evolution (LTE) transmitters is presented.
Abstract: This paper presents a SiGe envelope-tracking (ET) cascode power amplifier (PA) with an integrated CMOS envelope modulator for mobile WiMAX and 3GPP long-term evolution (LTE) transmitters (TXs). The entire ET-based RF PA system delivers the linear output power of 22.3/24.3 dBm with the overall power-added efficiency of 33%/42% at 2.4 GHz for the WiMAX 64 quadrature amplitude modulation (64QAM) and the 3GPP LTE 16 quadrature amplitude modulation, respectively. Additionally, it exhibits a highly efficient broadband characteristic for multiband applications. Compared to the conventional fixed-supply cascode PA, our ET-based cascode PA meets the WiMAX/LTE spectral mask and error vector magnitude spec at close to its P1dB compression without the need of predistortion. The SiGe PA and the CMOS envelope modulator are both designed and fabricated in the TSMC 0.35-μm SiGe BiCMOS process on the same die. This study represents an essential integration step toward achieving a fully monolithic large-signal ET-based TX for wideband wireless applications.

94 citations

Journal ArticleDOI
TL;DR: This paper discusses the design issues of highly efficient and monolithic wideband RF polar transmitters, especially the ones that use the envelope-tracking (ET) technique, and the system-on-a-chip design considerations of the monolithic polar transmitter using ET versus EER (envelope elimination and restoration).
Abstract: This paper discusses the design issues of highly efficient and monolithic wideband RF polar transmitters, especially the ones that use the envelope-tracking (ET) technique. Besides first reviewing the current state-of-the-art polar transmitters in the literature, three focus topics will be discussed: 1) the system-on-a-chip (SoC) design considerations of the monolithic polar transmitter using ET versus EER (envelope elimination and restoration); 2) the design of highly efficient envelope amplifier capable of achieving the high efficiency, current, bandwidth, accuracy and noise specifications required for wideband signals; and 3) the design of high-efficiency monolithic Si-based class E power amplifiers (PAs) suitable for ET-based RF polar transmitters. A design prototype of a polar transmitter using ET and a monolithic SiGe PA that passed the stringent low-band EDGE (Enhanced Data rates for GSM Evolution) transmit mask with 45% overall transmitter system efficiency will be given; the simulated data of the entire polar transmitter system is also compared against the measurement. Further investigations on how to solve the technical challenges to successfully implement linear and high-efficiency ET-based polar transmitter for broadband wireless applications such as WiBro/WiMAX are also discussed.

86 citations

Journal ArticleDOI
TL;DR: This paper presents a highly efficient silicon-based envelope-tracking power amplifier (ET-PA) for broadband wireless applications, designed using two integrated SiGe power cells fabricated in a 0.35- μm SiGe BiCMOS technology with through-silicon-via (TSV).
Abstract: This paper presents a highly efficient silicon-based envelope-tracking power amplifier (ET-PA) for broadband wireless applications. A pseudo-differential power amplifier (PA) is designed using two integrated SiGe power cells fabricated in a 0.35- μm SiGe BiCMOS technology with through-silicon-via (TSV). In the continuous-wave (CW) measurement, the PA achieves a saturated output power (POUT) of around 2 W with power-added efficiency (PAE) above 65% across the bandwidth of 0.7-1.0 GHz. To optimize the ET-PA system performance, several envelope shaping methods such as dc shifting, envelope scaling, envelope clipping, and envelope attenuation at back-off have been investigated carefully. A highly efficient monolithic CMOS envelope modulator (EM) integrated circuit (IC) is designed in a 0.35- μm bipolar-CMOS-DMOS (BCD) process to mate with our SiGe PA. With the LTE 16 QAM 5/10/20-MHz input signals, our ET-PA system achieves around 28 dBm linear POUT, passing the stringent LTE linearity specs such as the spectrum emission mask with an average composite system PAE of 42.3%/41.1%/40.2%, respectively. No predistortion is applied in this work.

79 citations

Journal ArticleDOI
Yan Li1, Jerry Lopez1, Cliff Schecht1, Ruili Wu1, Donald Y.C. Lie1 
TL;DR: The design insights for the implementation of a fully monolithic radio frequency (RF) power amplifier (PA) using both envelope-tracking and transistor resizing techniques for long-term evolution (LTE) applications are presented, which satisfies the LTE 16QAM linearity specs with high efficiency.
Abstract: This paper presents the design insights for the implementation of a fully monolithic radio frequency (RF) power amplifier (PA) using both envelope-tracking (ET) and transistor resizing techniques for long-term evolution (LTE) applications. At the low output power region, some of the power cells in the PA can be disabled to further save power consumption, thus enhancing the efficiency from a traditional ET-PA. Our ET-PA system is first realized with a two-chip solution, consisting of a high voltage envelope modulator fabricated in a 0.35 μm Bipolar-CMOS-DMOS (BCD) technology, and a differential cascode PA in a 0.35 μm SiGe BiCMOS technology. This two-chip solution of the ET-PA is to showcase the effective efficiency enhancement of using the transistor resizing method. In the second design, a CMOS envelope modulator is integrated with the cascode PA on the same die in the 0.35 μm SiGe BiCMOS technology. Some insights are demonstrated regarding the optimization of the envelope modulator specific to our cascode PA for LTE broadband signals, where the finite bandwidth and the switching frequency of the envelope modulator are considered for achieving the minimal error-vector magnitude (EVM) and spurious noise. The fully monolithic BiCMOS ET-PA reaches the maximum linear output power (Pout) of 24 dBm and 23.4 dBm with overall power-added-efficiency (PAE) of 41% and 38% for the LTE 16QAM 5 MHz and 10 MHz signals at 1.9 GHz, respectively, without needing predistortion. At the low power mode of our ET-PA, an additional PAE enhancement of 4% is obtained at Pout of 16-20 dBm by disabling some of the PA power cells. Our fully monolithic ET-PA satisfies the LTE 16QAM linearity specs with high efficiency.

75 citations

Proceedings ArticleDOI
11 Dec 2009
TL;DR: WiMAX/Wibro circuit and system co-design that include RF circuits and digital DSP blocks co-simulations suggest that the entire highly integrated ET-based transmit (TX) system can meet the stringent 802.16e mobile-WiMAX TX mask with 64QAM modulation and reach ∼33% peak system efficiency.
Abstract: This paper discusses both circuits and system design aspects of highly-efficient wideband RF polar transmitters for mobile WiMAX/Wibro applications using an open-loop envelope tracking (ET) technique. The design of linear-assisted switching envelope amplifier and monolithic SiGe class-E power amplifier (PA) is discussed, while the SPICE simulation results are compared with the measurement data. WiMAX/Wibro circuit and system co-design that include RF circuits and digital DSP blocks co-simulations suggest that the entire highly integrated ET-based transmit (TX) system can meet the stringent 802.16e mobile-WiMAX TX mask with 64QAM modulation and reach ∼33% peak system efficiency.

69 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors present a solution manual for the design of radio frequency integrated circuits (RFIC) solution manual, which can be found in the ePUB format.
Abstract: The Design Of Cmos Radio Frequency Integrated Circuits Solution Manual *FREE* the design of cmos radio frequency integrated circuits solution manual 4. RESISTA N CE . RESISTORS AND RESISTOR CIRCUITS Resistance is the op position to current flow in various degrees. The practical unit of resistance is called the ohm. A resistor on one ohm is physically very large but provides only a small resistance to current flow.The Design Of Cmos Radio Frequency Integrated Circuits the design of cmos radio frequency integrated circuits solution manual The Design Of Cmos Radio Frequency Integrated Circuits Solution Manual The Design Of Cmos Radio Frequency Integrated Circuits Solution Manual FREE the design of cmos radio frequency integrated circuits solution manual 4 RESISTA N CE Read The Design Of Cmos Radio Frequency Integrated Free Download Books The Design Of Cmos Radio Frequency Integrated Circuits Solution Manual You know that reading The Design Of Cmos Radio Frequency Integrated Circuits Solution Manual is beneficial because we are able to get a lot of information in the reading materials The design of cmos radio frequency integrated circuits Download The design of cmos radio frequency integrated circuits solution manual in EPUB Format In the website you will find a large variety of ePub PDF Kindle AudioBook and books Such as manual user assist The design of cmos radio frequency integrated circuits solution manual ePub comparison suggestions and The Design Of CMOS Radio Frequency Integrated Circuits The Design of CMOS Radio Frequency Integrated Circuits Solutions Manual Solutions Manuals are available for thousands of the most popular college and high school textbooks in subjects such as Math Science Physics Chemistry Biology Engineering Mechanical Electrical Civil Business and more The Design of CMOS Radio Frequency Integrated Circuits The Design of CMOS Radio Frequency Integrated Circuits Second Edition The last chapter will provide a trip down memory lane for some readers—a sampling of circuits of particular interest in RF history including the Regency TR 1 transistor radio design and the three transistor cicuit that created the first toy walkie talkie in 1962 PDF The Design of CMOS Radio Frequency Integrated PDF Student Solutions Manual Chapters 1 11 for Stewarts Single Variable Calculus Early Transcendentals 7th By James Stewart P D F PDF The Beginning Questions to Dr Malachi Z York El About By Malachi Z York El pdf PDF The Design of CMOS Radio Frequency Integrated PDF The Design of CMOS Radio Frequency Integrated Circuits Second Edition 2 DESCRIPTION This expanded and thoroughly revised edition of Thomas H Lee s acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems The Design of CMOS Radio Frequency Integrated Circuits Chapter 2 Basic MOS Device Physics In studying the design of integrated circuits one of two extreme approaches can b Design of Analog CMOS Integrated Circuits Chap 3 I X1 X2 Single Stage Amplifiers Figure 3 1 Input output characteristic of a nonlinear system The Design of CMOS Radio Frequency Integrated Circuits The Design of CMOS Radio Frequency Integrated Circuits Second Edition Thomas H Lee on Amazon com FREE shipping on qualifying offers This expanded and thoroughly revised edition of Thomas H Lee s acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems The chapters on low noise amplifiers The Design of CMOS Radio Frequency Integrated Circuits by The Design of CMOS Radio Frequency

213 citations

Book ChapterDOI
01 Jan 2003
TL;DR: In this paper, an expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems.
Abstract: This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

207 citations

Journal ArticleDOI
TL;DR: An improved envelope amplifier architecture for envelope tracking RF power amplifiers is presented, consisting of two switching amplifiers and one linear amplifier that provides wideband and high-efficiency operation.
Abstract: An improved envelope amplifier architecture for envelope tracking RF power amplifiers is presented, consisting of two switching amplifiers and one linear amplifier. The first switching amplifier and the linear amplifier provide wideband and high-efficiency operation, while the second switching amplifier provides a reduced bandwidth variable supply to the linear amplifier to further reduce power loss. The first switching amplifier and the linear amplifier are fabricated together in a 150 nm CMOS process, while the second switching amplifier is external. Measurements show a maximum average efficiency of 82% for a 10 MHz LTE signal with a 6 dB PAPR at 29.7 dBm output power and an SFDR of 63 dBc for a single tone of 5 MHz driving an 8 Ω load.

190 citations

Proceedings ArticleDOI
31 Dec 2012
TL;DR: A novel LTE user equipment (UE) power consumption model was developed for LTE system level optimization, because it is important to understand how network settings like scheduling of resources and transmit power control affect the UE's battery life.
Abstract: In this work a novel LTE user equipment (UE) power consumption model is presented. It was developed for LTE system level optimization, because it is important to understand how network settings like scheduling of resources and transmit power control affect the UE's battery life. The proposed model is based on a review of the major power consuming parts in an LTE UE radio modem. The model includes functions of UL and DL power and data rate. Measurements on a commercial LTE USB dongle were used to assign realistic power consumption values to each model parameter. Verification measurements on the dongle show that the model results in an average error of 2.6 %. The measurements show that UL transmit power and DL data rate determines the overall power consumption, while UL data rate and DL receive power have smaller impact.

130 citations