Feed-Forwarding the Output Voltage to Improve Efficiency for Envelope-Tracking Power Supply Based on a Switch-Linear Hybrid Scheme

Xiong, Xinhong; Ruan, Xinbo; Xi, Huan; Ge, Junji

doi:10.1109/tpel.2011.2119494

Cited by 21 publications

(8 citation statements)

References 15 publications

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“…As the operation in the CCM in steady state is guaranteed if k > k crit and the maximum possible value of k crit is 1 (according to (16)), then the operation in the CCM in steady state will be guaranteed if the ratio ω S /ω C satisfies: Table 8 shows the values of π/l 1 for the different types and orders of the filters under study. These values also represent a lower limit for the quotient ω S /ω C in the plots given in Fig.…”

Section: Vi1 Analysis Of the Conduction Mode In Steady Statementioning

confidence: 99%

“…20 shows the current though L 1 , i L1 , the average value of i L1 during a switching period as given by (20), i L1_avg , and the steady-state value of i L1_avg according to the duty cycle the converter is operating at, i L1_avg_ss . It is assumed that the converter has been designed to operate in the CCM in steady state for any duty cycle d c , which means that not only (16) is satisfied, but also (18). If a rising voltage step takes place at the filter input and the converter was operating in steady-state just before that event, then the converter will continue operating in the CCM after the step because the current through the inductor increases (see Fig.…”

Section: Vi2 Analysis Of the Conduction Mode During Transientsmentioning

confidence: 99%

“…The use of Envelope Tracking (ET) techniques has become an attractive option to increase the efficiency of Linear Power Amplifiers (LPAs) [1]- [16]. As it is well known, the maximum theoretical efficiency of a LPA depends on the relationship between the peak value of the signal at its output and its supply voltage.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, a switching-mode EA has to be used to improve system efficiency. Many types of switching-mode DC/DC converters have been proposed as EA [1]- [16], but those derived from the basic Buck converter [1], [3], [5], [6], [8]- [16]are especially attractive due to their simplicity, high efficiency and fast dynamic response.…”

Section: Introductionmentioning

confidence: 99%

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Analysis and Design of the Output Filter for Buck Envelope Amplifiers

Sebastián

Miaja

Rodríguez

et al. 2014

IEEE Trans. Power Electron.

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The efficiency of linear power amplifiers can be improved by modulating its supply voltage according to the peak value of the signal that is being amplified in a technique usually known as Envelope Tracking. High bandwidth DC/DC converters called Envelope Amplifiers (EA) are used to carry out the supply modulation in an efficient manner. In the case of linear Radio Frequency Power Amplifiers, the bandwidth requirements over the EA strongly depend on the signal being amplified: in modern telecommunication applications it can range from several hundred kHz to a few tens of MHz. The path to achieve such bandwidths usually goes through increased switching frequencies and/or reduced ratio of switching frequency to converter bandwidth. However, these may lead to lower converter efficiency and increased distortion, making the design of Envelope Amplifiers a challenging task. This paper addresses the analysis and design of the output filter for Buck converters operating as EA. The output filter must provide enough attenuation at the switching frequency and harmonics to guarantee a desired level of distortion while enabling tracking of widebandwidth envelope signals with high converter efficiency. This paper focuses on the use of high-order filters (up to sixth-order Bessel-Thomson, Butterworth and Legendre-Papoulis filters) in a Buck DC/DC converter working as an Envelope Amplifier. The filters are analytically described and characterized, and a design procedure that takes into account the major design constraints is proposed, allowing the selection of the appropriate filter for a given application. The proposed analysis and design method are supported by simulation results, as well as by experiments obtained using a 1 MHz Buck converter operating as an EA. Pablo F. Miaja (S'07 M'13) was born in Oviedo, Spain, in 1984. He received the M.S. degree in telecommunication engineering from the University of Oviedo in 2007 and in 2012 the PhD. degree from the same university. Since December 2007 he works as a researcher at the Electronic Power Supply Systems Group of the University of Oviedo. His research interests include dc/dc conversion, digital control of switched converters and power-supply systems for RF amplifiers. Alberto Rodríguez (S'07) was born in Oviedo, Spain, in 1981. He received the M.S. degree in telecommunication engineering in 2006 from the University of Oviedo, Gijón, Spain, where he is currently working towards the Ph.D. degree. In 2006, he has been a Telecommunications Engineer with the Government of the Principality of Asturias and an Assistant Professor with the Department of Electrical Engineering, University of Oviedo. Since 2007 he has been working in University of Oviedo at full time. His research interests are focused on multiple port power supply systems, bidirectional DC-DC power converters and wide band gap semiconductors. Miguel Rodríguez (S'06, M'11) was born in Gijón, Spain, in 1982. He received the M.S. degree and the Ph.D. degree in telecommunication engineering from the University of Oviedo ...

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Section: Vi1 Analysis Of the Conduction Mode In Steady Statementioning

confidence: 99%

Section: Vi2 Analysis Of the Conduction Mode During Transientsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Analysis and Design of the Output Filter for Buck Envelope Amplifiers

Sebastián

Miaja

Rodríguez

et al. 2014

IEEE Trans. Power Electron.

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“…The associate editor coordinating the review of this manuscript and approving it for publication was Ho Ching Iu. demand high dynamic performance, have applied different types of converters for applications such as in variable speed DC motor drivers [3], renewable energy systems [4]- [6], transportation systems [7], [8], hybrid energy storage system [9], [10], communications systems [11]. In several of these applications, converters are controlled by switching through Pulse Width-Modulation (PWM) to transfer power from a power source to loads having a constant power characteristic.…”

Section: Introductionmentioning

confidence: 99%

Interval Robust Controller to Minimize Oscillations Effects Caused by Constant Power Load in a DC Multi-Converter Buck-Buck System

et al. 2019

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Multi-converter electronic systems are becoming widely used in many industrial applications; therefore, the stability of the whole system is a big concern to the real-world power supplies applications. A multi-converter system comprised of cascaded converters has a basic configuration that consists of two or more converters in series connection, where the first is a source converter that maintains a regulated dc voltage on the intermediate bus while remaining are load converters that convert the intermediate bus voltage to the tightly regulated outputs for the next system stage or load. Instability in cascaded systems may occur due to the constant power load (CPL), which is a behavior of the tightly regulated converters. CPLs exhibit incremental negative resistance behavior causing a high risk of instability in interconnected converters. In addition, there are other problems apart from the CPL, e.g., non-linearities due to the inductive element and uncertainties due to the imprecision of a mathematical model of dc-dc converters. Aiming to effectively mitigate oscillations effects in the output of source converter loaded with a CPL, in this paper, an interval robust controller, by linear programming based on Kharitonov rectangle, is proposed to regulate the output of source converter. Several tests were developed by using an experimental plant and simulation models when the multi-converter buck-buck system is subjected to a variation of power reference. Both simulation and experimental results show the effectiveness of the proposed controller. Furthermore, the performance indices computed from the experimental data show that the proposed controller outperforms a classical control technique. INDEX TERMS Constant power load (CPL), multi-converter buck-buck system, parametric uncertainties, robust control based on Kharitonov rectangle, mitigation oscillations in multi-converter buck-buck system.

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