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Impact of time misalignment and input signal statistics in dynamically load-modulated amplifiers

Published online by Cambridge University Press:  01 June 2015

Konstantinos Mimis  and
Gavin Tomas Watkins
Konstantinos Mimis*
Affiliation:
Toshiba Research Europe Limited, 32 Queen Square, Bristol BS1 4ND, UK. Phone: +44(0)117 906 0773
Gavin Tomas Watkins
Affiliation:
Toshiba Research Europe Limited, 32 Queen Square, Bristol BS1 4ND, UK. Phone: +44(0)117 906 0773
*
Corresponding author: K. Mimis Email: konstantinos.mimis@toshiba-trel.com
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Abstract

The effect of time misalignment between the radiofrequency (RF) input and tunable matching network control signal in dynamically load-modulated power amplifiers (Pas) is investigated in theory and practice. Moreover, the impact of different input signal statistics is considered. A simple amplifier model is used for the study, based on which the impact on output power, efficiency, and linearity is explored with various generic multi-tone signals. Furthermore, to experimentally verify the results, a 10 W dynamically load-modulated RF PA is measured. As expected, proper synchronization of the signals is crucial, especially as channel bandwidth increases. Additionally, it is shown that the input signal characteristics, such as the amplitude distribution, are important. Moreover, the prototype RF PA is measured with a 1.4 MHz long-term evolution (LTE) signal delivering an average output power of 33.9 dBm with 46% efficiency. Finally, high efficiency and linearity is maintained over output power by scaling the drain supply voltage.

Keywords

Power amplifiers and linearizersMicrowave measurements
Type
Research Papers
Information
International Journal of Microwave and Wireless Technologies , Volume 7 , Special Issue 3-4: European Microwave Week 2014 , June 2015 , pp. 327 - 337
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2015 

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