Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-17T21:15:53.810Z Has data issue: false hasContentIssue false

Digital predistortion of envelope-tracking power amplifiers under average power back-off and long-term average power efficiency for base-station applications

Published online by Cambridge University Press:  18 February 2013

Jonmei J. Yan*
Affiliation:
ECE Department, University of California, San Diego, 9500 Gilman Dr. 0407, La Jolla, CA, USA MaXentric Technologies, La Jolla, CA, USA
Paul Draxler
Affiliation:
ECE Department, University of California, San Diego, 9500 Gilman Dr. 0407, La Jolla, CA, USA Qualcomm Inc., San Diego, CA, USA
Calogero D. Presti
Affiliation:
ECE Department, University of California, San Diego, 9500 Gilman Dr. 0407, La Jolla, CA, USA
Donald F. Kimball
Affiliation:
ECE Department, University of California, San Diego, 9500 Gilman Dr. 0407, La Jolla, CA, USA MaXentric Technologies, La Jolla, CA, USA
Peter M. Asbeck
Affiliation:
ECE Department, University of California, San Diego, 9500 Gilman Dr. 0407, La Jolla, CA, USA
*
Corresponding author: Jonmei J. Yan Email: jyan@ieee.org

Abstract

In many base-station applications, the load/usage fluctuates over time periods of hours to days, thereby varying the required transmit power by as much as 10 dB. It is desirable to maintain high efficiency and linearity in the power amplifier under these back-off conditions in order to achieve high long-term efficiency. This paper demonstrates a scalable digital predistortion (DPD) approach that can be applied under different power back-off levels in envelope-tracking (ET) amplifiers and quantifies the associated efficiency. Efficiency comparisons are made with other amplifier configurations such as Class B and Doherty. Efficiency of 60% at full power (35 W average power) and >30% efficiency at 10 dB average power back-off are measured in an ET amplifier with a 7.54 dB peak-to-average ratio (PAPR) single-carrier WCDMA signal while meeting linearity specifications. Long-term base-station usage probability functions are presented. The long-term efficiency of the ET amplifiers is simulated to be greater than that of Class B and Doherty amplifiers.

Type
Research Papers
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Cripps, S.C.: RF Power Amplifiers for Wireless Communications. Artech House, Norwood, MA, 2006.Google Scholar
[2]Raab, F.H. et al. : Power amplifiers and transmitters for RF and microwave. MTT, IEEE Trans., 50 (3) (2002), 814826.Google Scholar
[3]Steinbeiser, C. et al. : 250 W HVHBT Doherty with 57% WCDMA efficiency linearized to −55 dBc for 2c11 6.5 dB PAR. JSSC, 43 (10) (2008), 22182228.Google Scholar
[4]Kim, I. et al. : Optimized design of a highly efficient three-stage Doherty PA using gate adaptation. MTT, IEEE Trans., 58 (10) (2010), 25622574.Google Scholar
[5]Jeong, J. et al. : Modeling and design of RF amplifiers for envelope tracking WCDMA base-station applications. MTT, IEEE Trans., 57 (9) (2009), 21482159.Google Scholar
[6]Wang, F. et al. : Design of wide-bandwidth envelope-tracking power amplifiers for OFDM applications. MTT, IEEE Trans., 53 (4) (2005), 12441255.Google Scholar
[7]Asbeck, P. et al. : High dynamic range, high efficiency power amplifiers for wireless communications, in BCTM 2005, IEEE, Santa Barbara, CA, 2005.Google Scholar
[8]Yang, Y. et al. : High efficiency CDMA power amplifier with dynamic current control circuits, in CSICS, 2004. IEEE, Monterey, CA, October 2004.Google Scholar
[9]Bumman, K. et al. : Efficiently amplified. IEEE Microw. Mag., 11 (5) (2010), 87100.Google Scholar