Modified Output Combining 3-Stage Doherty Power Amplifier Design for LTE Micro eNodeB

Full Text (PDF, 541KB), PP.10-24

Views: 0 Downloads: 0

Author(s)

Brijesh Shah 1,* Niket Thakker 2 Gaurav Dalwadi 1 Nikhil Kothari 2

1. RF Quality Assurance, Reliance Jio Infocomm Ltd., Navi Mumbai-400701, India

2. Electronics & Communication, Dharmsinh Desai University, Nadiad-387001, India

* Corresponding author.

DOI: https://doi.org/10.5815/ijwmt.2015.05.02

Received: 4 Jun. 2015 / Revised: 8 Jul. 2015 / Accepted: 12 Aug. 2015 / Published: 8 Sep. 2015

Index Terms

DPA, Modified output combing techniques, LTE, Micro eNodeB, LDMOS

Abstract

This paper presents a highly efficient modified output combining 3-stage Doherty Power Amplifier (DPA) design using low power LDMOS transistor for Band 40, TD-LTE Micro eNodeB. In this design, modified output combining technique has been used in the output section which meets the output power requirements of Micro eNodeB which cannot be achieved by conventional 3-stage DPA. The modified DPA design achieves 65.3% power added efficiency (PAE) at 39 dBm average output power with 20 MHz LTE signal using 15 watt LDMOS Transistor. 3-stage modified output combining technique increases the linear output power by 1.1 dB and increases the Gain flatness versus power level. The use of Digital Pre-Distortion (DPD) along with modified 3-stage DPA design achieves the linearity requirements as per the 3GPP specifications. The modified DPA combining technique has provided potential economical solution by using low power LDMOS transistor with an advantage of high efficiency.

Cite This Paper

Brijesh Shah, Niket Thakker, Gaurav Dalwadi, Nikhil Kothari,"Modified Output Combining 3-Stage Doherty Power Amplifier Design for LTE Micro eNodeB", IJWMT, vol.5, no.5, pp.10-24, 2015. DOI: 10.5815/ijwmt.2015.05.02

Reference

[1]Ericsson Mobility Report, Feb., 2015, Available Online: http://www.ericsson.com/res/docs/2015/ericsson-mobility-report-feb-2015-interim.pdf.

[2]Khondokar Fida Hasan, Md. Morshedul Islam, "Evolution of 4th Generation Mobile Communication Network: LTE-Advance". Int. J. Comp. Tech. Appl., Vol 2 (4), 1092-1098.

[3]Albrecht J. Fehske, Fred Richter, Gerhard P. Fettweis, "Energy efficiency improvements through micro sites in cellular mobile radio networks", Globecome Workshops, 2009.

[4]Mohammed H. Alsharif, Rosdiadee Nordin, Mahamod Ismail, "Survey of Green Radio Communications Networks: Techniques and Recent Advances," Journal of Computer Networks and Communications, vol. 2013, Article ID 453893, 13 pages, 2013. 

[5]Technical Specifications - TS 36.141 version 11.4.0 Release 11, LTE: Evolved Universal Terrestrial Radio Access (E-UTRA) Base Station Conformance Testing, 3GPP Group, Apr. 2013.

[6]F. H. Raab, "Intermodulation distortion in Kahn-technique transmitters," IEEE Trans. Microw. Theory Tech., vol. 44, no. 12, pp. 2273–2278, Dec.1996. 

[7]F. H. Raab et al., "Power amplifiers and transmitter for RF and microwave," IEEE Trans. Microw. Theory Tech., vol. 50, no. 3, pp. 814–826, Mar. 2002. 

[8]J. Staudinger et al., "High efficiency CDMA power amplifier using dynamic envelope tracking technique," IEEE MTT-S Int. Microwave Symp. Dig., 2000, pp. 873–876. 

[9]J. Son et al., "3.5-GHz High Efficient Envelope Tracking Transmitter System for Base Station," Proc. 40th Eur. Microw. Conf., Paris, France, Sept. 2010.

[10]J. Staudinger et al., "800 MHz power amplifier using envelope following technique," IEEE Radio Wireless Conf., pp. 301–304, Aug. 1999.

[11]S. C. Cripps, RF Power Amplifier for Wireless Communications, Artech House, 1999.

[12]Gaurav Dalwadi et al., "Efficient Doherty Feed-Forward Linear Power Amplifier for CDMA 2000 Base-station Applications," IEEE Int. Conf. Signal processing, Communication and Networking, pp. 35-40, Jan. 2008.

[13]Vani Vishwanathan, "Efficiency Enhancement of Base Station Power Amplifier using Doherty Technique", M.Tech Thesis, Virginia Polytechnic Institute and State University.

[14]Paolo Colantonio et al., "The AB-C Doherty Power Amplifier. Part II: Validation", International Journal of RF and Microwave Computer-Aided Engineering, July. 2008.

[15]Dongsu Kim et al., "High efficiency and wideband envelope tracking power amplifier with sweet spot tracking," Radio Frequency Integrated Circuits Symposium (RFIC), 2010 IEEE , vol., no., pp.255, 258, 23-25 May 2010.

[16]J. Son et al., "3.5-GHz High Efficient Envelope Tracking Transmitter System for Base Station," Proc. 40th Eur. Microw. Conf., Paris, France, Sept. 2010.

[17]Zhibin Zeng, Dian Xie, Yaqian Huang, "A Crest Factor Reduction Method in Digital Predistortion for Improvement of Power Efficiency," ICCSEE, vol.3, pp. 636-639, 2012.

[18]T. Kikkawa et al., "GaN Device for Highly Efficient Power Amplifiers," Fujitsu Sci. Tech. Journal, vol. 48, No.1, pp 40-46, Jan. 2012.

[19]H. Matsubara, F. Kawanabe, T. Nojima, "A 2-GHz band experiment on efficiency enhancement of a GaN power amplifier using 2nd harmonic injection," Microwave Conference, 2008. APMC 2008. Asia-Pacific, vol., no., pp.1, 4, 16-20 Dec. 2008.

[20]A. Markos et al., "Design of a 120 W balanced GaN Doherty power amplifier," Microwave Conference (GeMIC), 2011 German, vol., no., pp.1, 4, 14-16 March 2011.

[21]Khaled Bathich, "Analysis and Design of Efficiency-Enhancement Microwave Power Amplifiers Using the Doherty Technique", Master's thesis, Berlin Institute of Technologies, Berlin, July 2013.

[22]Luca Piazzon et al., "Asymmetrical Doherty Power Amplifier with an Integrated Drive Stage in Auxiliary path", International Journal of RF and Microwave Computer-Aided Engineering, Oct., 2013.

[23]M. Iwamoto et al., "An Extended Doherty Amplifier with High Efficiency Over a Wide Power Range," IEEE Transactions on Microwave Theory and Techniques, vol. 49, no. 12, pp. 2472-2479, Dec. 2001.

[24]A. Z. Markos et al., "A 50W Unsymmetrical GaN Doherty Amplifier for LTE Applications," Proceedings of the 40th European Microwave Conference, pp. 994-997, Paris, France, Sep. 2010.

[25]A. Z. Markos et al., "A 6W Uneven Doherty Power Amplifier in GaN Technology," Proceedings of the 2nd European Microwave Integrated Circuits Conference (EuMIC), pp. 299-302, Munich, Germany, Sep. 2007.

[26]J. Kim et al., "Optimum Operation of Asymmetrical-Cells-Based Linear Doherty Power Amplifier-Uneven Power Drive and Power Matching," IEEE Transactions on Microwave Theory and Techniques, vol. 53, no. 5, pp. 1802-1809, May 2005.

[27]B. Kim, I. Kim, J. Moon, "Advanced Doherty Architecture," IEEE Transactions on Microwave Magazine, Aug. 2010.

[28]Grebennikov Andrei, "High-Efficiency advanced Multistage Doherty GaN HEMT Power Amplifiers," RF Technology International Magazine, February 2012.

[29]F. I. Yasuda et al., "FPGA Implementation of a Fix-Point Digital Baseband Pre-Distorter for the Linearization of Wireless Transmitters" – Departamento de Engenharia Elétrical Universidade Federal do Paraná, Curitiba, Brasil.