Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-28T04:39:22.944Z Has data issue: false hasContentIssue false
  • English
  • Français

Design and performance of multi-channel switched sequential amplifiers

Published online by Cambridge University Press:  19 June 2009

Thomas Lehmann  and
Reinhard Knoechel
Thomas Lehmann*
Affiliation:
Institute of Electrical and Information Engineering, Microwave Laboratory, University of Kiel, Kaiserstrasse 2, 24143 Kiel, Germany. Phone: +494318806167; Fax: +494318806152.
Reinhard Knoechel
Affiliation:
Institute of Electrical and Information Engineering, Microwave Laboratory, University of Kiel, Kaiserstrasse 2, 24143 Kiel, Germany. Phone: +494318806167; Fax: +494318806152.
*
Corresponding author: T. Lehmann Email: tl@tf.uni-kiel.de
Get access Rights & Permissions [Opens in a new window]

Abstract

This paper presents switched sequential amplifiers (SSAs) using reconfigurable directional couplers as power splitters and combiners. The SSA concept allows matching the efficiency characteristics to the amplitude probability density distribution of the applied modulated signal. Therefore the back-off efficiency can be increased significantly. A three-channel SSA can e.g. theoretically achieve a −10 dB back-off efficiency exceeding 50%. Design parameters and potential efficiency enhancement are discussed for two- and three-channel SSAs. After a brief introduction of the used switched couplers, the circuit concept for two- and three-channel SSAs is described. Calculations for the possible efficiency enhancement are presented. Also signal distortions by the directional couplers are outlined. The paper closes with experimental results for a two-channel SSA.

Keywords

EfficiencyReconfigurable architecturesrf power amplcifiersCouplers
Type
Original Article
Information
International Journal of Microwave and Wireless Technologies , Volume 1 , Special Issue 4: European Microwave Week 2008 , August 2009 , pp. 269 - 275
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2009

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]Hannington, G.; Chen, P.; Asbeck, P.; Larson, L.: High efficiency power amplifier using dynamic power-supply voltage for CDMA applications. IEEE Trans. Microwave Theory Tech., 47 (1999), 1471–1476. doi: 10.1109/22.780397.CrossRefGoogle Scholar
[2]Doherty, W.H.: A new high efficiency power amplifier for modulated waves. Proc. Inst. Radio Eng., 24 (1936), 1163–1182.Google Scholar
[3]Cripps, S.C.: RF Power Amplifiers for Wireless Communications, Artech House, Norwood, MA, 1999.Google Scholar
[4]Lehmann, T.; Hettstedt, F.; Knoechel, R.: Reconfigurable PA networks using switchable directional couplers as RF Switch, in Proc. 37th European Microwave Conf., 2007, 1054–1057. doi: 10.1109/EUMC.2007.4405378.CrossRefGoogle Scholar
[5]Lehmann, T.; Knoechel, R.: Wideband sequential amplifier with switched directional couplers, in Proc. German Microwave Conf., 2008, 105–108.Google Scholar
[6]Lehmann, T.; Knoechel, R.: Multi stage switched sequential amplifiers, in Proc. 38th European Microwave Conf., 2008, 448–451. doi: 10.1109/EUMC.2008.4751485.CrossRefGoogle Scholar
[7]Lehmann, T.; Hettstedt, F.; Knoechel, R.: New switchable directional couplers for reconfigurable rf networks, in Proc. 37th European Microwave Conf., 2007, 564–567. doi: 10.1109/EUMC.2007.4405253.CrossRefGoogle Scholar
[8]Lehmann, T.; Knoechel, R.: Power amplifier efficiency enhancement using adaptive load transformation, in Proc. German Microwave Conf., 2009.CrossRefGoogle Scholar