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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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References

REFERENCES

[1] Cripps, S.C.: RF Power Amplifiers for Wireless Communications, 2nd ed., Artech House Inc., Norwood, MA, 2006.Google Scholar
[2] Kenle, C.; Peroulis, D.: Design of adaptive highly efficient GaN power amplifier for octave-bandwidth application and dynamic load modulation. IEEE Trans. Microw. Theory Tech., 60 (6) (2012), 1829–1839.Google Scholar
[3] Moon, J.; Son, J.; Lee, J.; Bumman, K.: A multimode/multiband envelope tracking transmitter with broadband saturated amplifier. IEEE Trans. Microw. Theory Tech., 59 (12) (2011), 3463–3473.CrossRefGoogle Scholar
[4] Nemati, H.M. et al. : Evaluation of a GaN HEMT transistor for load-and supply-modulation applications using intrinsic waveform measurements, in Microwave Symp. Digest, 2010, IEEE MTT-S Int., Anaheim, CA, USA, 2010, 509–512.Google Scholar
[5] Raab, F.H.: High-efficiency linear amplification by dynamic load modulation, in Microwave Symp. Digest, 2003, IEEE MTT-S Int., Philadelphia, PA, USA, 2003, 1717–1720.Google Scholar
[6] Andersson, C.M. et al. : Theory and design of class-J power amplifier with dynamic load modulation. IEEE Trans. Microw. Theory Tech., 60 (12) (2012), 3778–3786.Google Scholar
[7] Cao, H.; Nemati, H.M.; Tehrani, A.S.; Eriksson, T.; Grahn, J.; Fager, C.: Linearisation of efficiency-optimised dynamic load modulation transmitter architectures. IEEE Trans. Microw. Theory Tech., 58 (4) (2010), 873–881.Google Scholar
[8] Arnous, M.T. et al. : Evaluation of GaN-HEMT power amplifiers using BST-based components for load modulation. Int. J. Microw. Wireless Tech., 6 (2014), 253–263.Google Scholar
[9] Andersson, C.M. et al. : A packaged 86 W GaN transmitter with SiC varactor-based dynamic load modulation, in 43th European Microwave Conf., 2013, EuMC 2013, Nuremberg, Germany, 2013, 1211–1214.Google Scholar
[10] Tehrani, A.S.; Nemati, H.M.; Haiying, C.; Eriksson, T.; Fager, C.: Dynamic load modulation of high power amplifiers with varactor-based matching networks, in Microwave Symp. Digest, 2009, in IEEE MTT-S Int., Boston, MA, USA, 2009, 1537–1540.CrossRefGoogle Scholar
[11] Mimis, K.; Watkins, G.T.: Bandwidth reduction in dynamic load-modulated power amplifiers: control and RF signal expansion, efficiency and linearity trade-offs, in IEEE Topical Conf. on Power Amplifiers for Wireless & Radio Applications, 2015, PAWR 2015, San Diego, California, USA, 2015, 49–51.Google Scholar
[12] Cao, H.; Fager, C.; Khan, T.; Tehrani, A.S.; Eriksson, T.: Comparison of bandwidth reduction schemes in dynamic load modulation power amplifier architectures, in Workshop on Integrated Nonlinear Microwave and Millimeter-Wave Circuits, INMMIC 2011, Vienna, Austria, 2011, 1–4.Google Scholar
[13] Raab, F.H.: Intermodulation distortion in Kahn-technique transmitters. IEEE Trans. Microw. Theory Tech., 44 (12) (1996), 2273–2278.Google Scholar
[14] Cao, H.; Tehrani, A.S.; Nemati, H.M.; Fager, C.; Eriksson, T.; Zirath, H.: Time alignment in a dynamic load modulation transmitter architecture, in 39th European Microwave Conf., 2009, EuMC 2009, Rome, Italy, 2009, 1211–1214.CrossRefGoogle Scholar
[15] Rudolph, D.: Kahn EER technique with single-carrier digital modulations. IEEE Trans. Microw. Theory Tech., 51 (2) (2003), 2273–2278.Google Scholar
[16] Mimis, K.; Watkins, G.T.: Experimental investigation of signal time misalignment in dynamic load modulation amplifiers, in 44th European Microwave Conf., 2014. EuMC 2014, Rome, Italy, 2014, 1356–1359.Google Scholar
[17] Mimis, K.; Bensmida, S.; Morris, K.A.; McGeehan, J.P.: Continuous harmonically tuned Class-B power amplifier: A closed form equation design approach, in Microwave Symp. Digest, 2012, in IEEE MTT-S Int., Montreal, QC, Canada, 2012, 1–3.Google Scholar
[18] Colantonio, P.; Giannini, F.; Leuzzi, G.; Limiti, E.: On the Class-F power amplifier design. Int. J. RF and Microw. Computer-Aided Eng., 9 (2) (1999), 129–149.Google Scholar
[19] Rautio, T.; Rahkonen, T.: The effects of timing skew in envelope tracking and EER type transmitters, in 39th European Microwave Conf., 2009. EuMC 2009, Rome, Italy, 2009, 346–349.Google Scholar
[20] Watkins, G.T.: High bandwidth current mode amplifier for envelope modulated RF amplifiers. IET Electron. Lett.,, 46 (13) (2010), 894–895.CrossRefGoogle Scholar
[21] Bensmida, S. et al. : Overlapped segment piece-wise polynomial pre-distortion for the linearisation of power amplifiers in the presence of high PAPR OFDM signals, in Microwave Symp. Digest, 2012, in IEEE MTT-S Int., Montreal, QC, Canada, 2011, 1–3.Google Scholar
[22] Mimis, K.; Watkins, G.T.: A reactively load-modulated RF low-power amplifier with multilevel supply voltage for multi-standard RF front-ends, in German Microwave Conf., 2014, GeMIC, Aachen, Germany, 2014, 1–4.Google Scholar
[23] Nemati, H.M.; Fager, C.; Gustavsson, U.; Jos, R.; Zirath, H.: Design of varactor-based tunable matching networks for dynamic load modulation of high power amplifiers. IEEE Trans. Microw. Theory Tech., 57 (5) (2009), 1110–1118.Google Scholar
[24] Nemati, H.M.; Haiying, C.; Almgren, B.; Eriksson, T.; Fager, C.: Design of highly efficient load modulation transmitter for wideband cellular applications. IEEE Trans. Microw. Theory Tech., 58 (11) (2010), 2820–2828.Google Scholar