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Design and analysis of 80-W wideband asymmetrical Doherty amplifier

Published online by Cambridge University Press:  01 April 2014

Khaled Bathich  and
Georg Boeck
Khaled Bathich*
Affiliation:
Microwave Engineering Laboratory, Berlin Institute of Technology, Einsteinufer 25, D-10587, Berlin, Germany
Georg Boeck
Affiliation:
Microwave Engineering Laboratory, Berlin Institute of Technology, Einsteinufer 25, D-10587, Berlin, Germany
*
Corresponding author: K. Bathich Email: [email protected]
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Abstract

This paper presents the analysis and design of a wideband asymmetrical Doherty amplifier. The frequency response of the output combining network of the Doherty amplifier with arbitrary back-off level configuration is analyzed. Other bandwidth-limiting factors were discussed and analyzed as well. A number of performance enhancement techniques were taken into consideration to obtain high and flat back-off efficiency over the amplifier design band of 1.7–2.25 GHz. The designed Doherty amplifier had, at 8.0–9.9 dB output back-off, a minimum efficiency of η = 50% [power-added efficiency of 45%], measured near 40 dBm of output power, and over 28% bandwidth. Using digital predistortion (DPD) linearization, an adjacent-channel leakage ratio (ACLR) of −43 dBc was obtained for a single-carrier W-CDMA signal, at 40.9 dBm and 46% of average output power and drain efficiency, respectively. The designed amplifier represents the first wideband Doherty amplifier reported over extended power back-off range.

Keywords

Power amplifiers and linearizersCircuit design and applications
Type
Research Papers
Information
International Journal of Microwave and Wireless Technologies , Volume 7 , Issue 1 , February 2015 , pp. 13 - 18
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2014 

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References

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