The Ripple Cancellation Technique Applied to a Synchronous Buck Converter to Achieve a Very High Bandwidth and Very High Efficiency Envelope Amplifier

This paper presents a single-stage converter for a high-bandwidth and high-efficiency envelope amplifier. In the proposed application, due to the high peak-to-average-power ratio, high bandwidth, and the power level requirements, the envelope amplifier has low efficiency. Therefore, many efforts have been made to increase the efficiency of the envelope amplifier. To achieve this improvement, the current ripple cancellation technique is applied in this paper to a synchronous buck converter to cancel the output current ripple and to decrease the switching frequency without a reduction in the large signal bandwidth, for open-loop operation and for the envelope elimination and restoration technique. The advantages of the proposed design are presented and validated experimentally. The transfer function of the output filter of the buck converter with a ripple cancellation circuit has been modeled and compared to measurements, showing a good correspondence. Experimental validation is provided at 4 MHz of switching frequency, for dc and for variable output voltage, applying a sinusoidal reference and a 64-QAM signal. Experimental validation of the efficiency improvement is provided, compared to the equivalent design of the conventional buck converter in terms of the output voltage ripple rejection ratio and large signal bandwidth.

[1]  Peter M. Asbeck,et al.  Wideband high efficiency digitally-assisted envelope amplifier with dual switching stages for radio base-station envelope tracking power amplifiers , 2010, 2010 IEEE MTT-S International Microwave Symposium.

[2]  Claudio Adragna,et al.  Ripple steering AC-DC converters to minimize input filter , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[3]  D. J. Perreault,et al.  Design of variable-resistance class E inverters for load modulation , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[4]  Yanfei Liu,et al.  New class-E DC-to-DC converter topologies with constant switching frequency , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[5]  Xinbo Ruan,et al.  Feed-Forwarding the Output Voltage to Improve Efficiency for Envelope-Tracking Power Supply Based on a Switch-Linear Hybrid Scheme , 2011, IEEE Transactions on Power Electronics.

[6]  Eduard Alarcón,et al.  Efficiency optimization in linear-assisted switching power converters for envelope tracking in RF power amplifiers , 2005, 2005 IEEE International Symposium on Circuits and Systems.

[7]  R. Martinelli,et al.  Coupled inductor boost converter with input and output ripple cancellation , 1991, [Proceedings] APEC '91: Sixth Annual Applied Power Electronics Conference and Exhibition.

[8]  T.C. Neugebauer,et al.  Coupled-Magnetic Filters With Adaptive Inductance Cancellation , 2005, IEEE Transactions on Power Electronics.

[9]  Frederick H. Raab,et al.  Idealized operation of the class E tuned power amplifier , 1977 .

[10]  Jeffrey S. Walling,et al.  A switched-capacitor power amplifier for EER/polar transmitters , 2011, 2011 IEEE International Solid-State Circuits Conference.

[11]  O. Garcia,et al.  Dynamic Analysis of a Boost Converter With Ripple Cancellation Network by Model-Reduction Techniques , 2009, IEEE Transactions on Power Electronics.

[12]  O. Garcia,et al.  Efficient and Linear Power Amplifier Based on Envelope Elimination and Restoration , 2012, IEEE Transactions on Power Electronics.

[13]  O. Garcia,et al.  Multilevel Power Supply for High Efficiency RF Amplifiers , 2010, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[14]  Wenxin Huang,et al.  Single-Stage Boost Inverter With Coupled Inductor , 2012, IEEE Transactions on Power Electronics.

[15]  O. Garcia,et al.  Optimal design of envelope amplifier based on linear-assisted buck converter , 2012, 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[16]  R. Steigerwald,et al.  Ripple current cancellation circuit , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[17]  Fred C. Lee,et al.  Passive input current ripple cancellation in three-phase discontinuous conduction mode rectifiers , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[18]  Johann W. Kolar,et al.  Novel aspects of an application of 'zero'-ripple techniques to basic converter topologies , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[19]  N Singhal,et al.  A Zero-Voltage-Switching Contour-Based Power Amplifier With Minimal Efficiency Degradation Under Back-Off , 2011, IEEE Transactions on Microwave Theory and Techniques.

[20]  Xinbo Ruan,et al.  Full Feedforward of the Output Voltage to Improve Efficiency for Envelope-Tracking Power Supply Using Switch-Linear Hybrid Configuration , 2013, IEEE Transactions on Power Electronics.

[21]  P. T. Krein,et al.  A 'zero' ripple technique applicable to any DC converter , 1999, 30th Annual IEEE Power Electronics Specialists Conference. Record. (Cat. No.99CH36321).