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Highly efficient 3-stage Doherty power amplifier using gate bias adaption

Published online by Cambridge University Press:  22 November 2010

Ildu Kim ,
Junghwan Moon ,
Jungjoon Kim ,
Seunghoon Jee ,
Junghwan Son  and
Bumman Kim
Ildu Kim
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
Junghwan Moon
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
Jungjoon Kim
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
Seunghoon Jee
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
Junghwan Son
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
Bumman Kim*
Affiliation:
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, 790-784, Republic of Korea.
*
Corresponding author: Bumman Kim Email: bmkim@postech.ac.kr
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Abstract

This paper demonstrates a highly efficient 3-stage Doherty power amplifier (PA) employing an envelope tracking (ET) technique. The ‘3-stage’ Doherty PA is the most efficient architecture for a high peak-to-average power ratio (PAPR) signal among the various Doherty PAs. However, because of the lower peaking biases than those of the ‘N-way’ Doherty PA, the proper load modulation is hard to be achieved. To get proper modulation, the peaking PAs' gate biases have been adaptively controlled using the ET technique, and the peak power and maximum efficiency characteristic along the backed-off output power region is successfully achieved. By ADS and Matlab simulations, the overall behavior of the 3-stage Doherty PA employing the ET technique has been fully analyzed. To maximize the overall efficiency of the proposed 3-stage Doherty PA, the unit PA has been designed using class F−1 PA. For verification, the amplifier is implemented using 5 W and 10 W PEP LDMOSFETs for the 802.16e mobile world interoperability for microwave access (WiMAX) at 1 GHz with a 8.5 dB PAPR. The measured drain efficiency of the proposed 3-stage Doherty PA is 55.5% at an average output power of 37 dBm, which is a 7.54 dB backed-off output power. The digital feedback predistortion (DFBPD) algorithm has been used to linearize the proposed PA considering the ET technique. After linearization, the −33.15 dB of relative constellation error (RCE) performance is achieved, satisfying the system specification. These results show that the 3-stage Doherty employing the ET technique and saturated PA is the most suitable PA for the highly efficient and linear transmitter.

Keywords

RF transmitterPower amplifier (PA)N-way Doherty PA3-stage Doherty PAEnvelope tracking (ET)Power-added efficiency (PAE)Relative constellation error (RCE)Peak-to-average power ratio (PAPR)EfficiencyLinearityWorld interoperability for microwave access (WiMAX)Digital feedback predistortion (DFBPD)
Type
Original Article
Information
International Journal of Microwave and Wireless Technologies , Volume 3 , Issue 1 , February 2011 , pp. 47 - 58
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2010

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References

REFERENCES

[1]Woo, Y. et al. : Adaptive digital feedback predistortion technique for linearizing power amplifier. IEEE Trans. Microw. Theory Tech., 55 (5) (2007), 932–940.CrossRefGoogle Scholar
[2]Doherty, W. H.: A new high efficiency power amplifier for modulated waves. Proc. IRE., 24 (9) (1936), 1163–1182.CrossRefGoogle Scholar
[3]Raab, F. H.: Efficiency of doherty RF power-amplifier systems. IEEE Trans. Broadcasting, BC-33 (3) (1987), 77–83.CrossRefGoogle Scholar
[4]Kim, I. et al. : Highly linear three-way Doherty amplifier with uneven power drive for repeater system. IEEE Microw. Wirel. Compon. Lett., 16 (4) (2006), 176–178.Google Scholar
[5]Wang, F. et al. : An improved power-added efficiency 19-dBm hybrid envelope elimination and restoration power amplifier for 802.11g WLAN applications. IEEE Trans. Microw. Theory Tech., 54 (12) (2006), 4086–4099.CrossRefGoogle Scholar
[6]Kim, I.; Woo, Y.Y.; Kim, J.; Moon, J.; Kim, J.; Kim, B.: High-efficiency hybrid EER transmitter using optimized power amplifier. IEEE Trans. Microw. Theory Tech., 56 (11) (2008), 2582–2593.Google Scholar
[7]Kimball, D. F. et al. : High-efficiency envelope-tracking W-CDMA base-station amplifier using GaN HFETs. IEEE Trans. Microw. Theory Tech., 54 (11) (2006), 3848–3856.CrossRefGoogle Scholar
[8]Kim, I.; Kim, J.; Moon, J.; Kim, B.: Optimized envelope shaping for hybrid EER transmitter of mobile WiMAX-optimized ET operation. IEEE Microw. Wirel. Compon. Lett., 19 (5) (2009), 335–337.Google Scholar
[9]Choi, J.; Kang, D.; Kim, D.; Park, J.; Kim, B.: Power amplifiers and transmitters for next generation mobile handset. J. Semicond. Technol. Sci., 9 (4) (2009), 249–256.CrossRefGoogle Scholar
[10]Cripps, S. C.: RF Power Amplifiers for Wireless Communications. Artech House, Norwood, MA, (2006).Google Scholar
[11]Deguchi, H.; Ui, N.; Ebihara, K.; Inoue, K.; Yoshimura, N.; Takahashi, H.: A 33W GaN HEMT Doherty amplifier with 55% drain efficiency for 2.6 GHz base stations, in IEEE MTT-S Int. Microwave Symp. Digest., June 2009, 1273–1276.CrossRefGoogle Scholar
[12]Pelk, M.J.; Neo, W.C.E.; Gajadharsing, J.R.; Pengelly, R.S.; de Vreede, L.C.N.: A high-efficiency 100-W GaN three-way doherty amplifier for base-station applications. IEEE Trans. Microw. Theory Tech., 56 (7) (2008), 1582–1591.CrossRefGoogle Scholar
[13]Yang, Y.; Cha, J.; Shin, B.; Kim, B.: A fully matched N-way Doherty amplifier with optimized linearity. IEEE Trans. Microw. Theory Tech., 51 (3) (2003), 986–993.CrossRefGoogle Scholar
[14]Neo, W.C.E.; Qureshi, J.; Pelk, M.J.; Gajadharsing, J.R.; de Vreede, L.C.N.: A mixed-signal approach towards linear and efficient N-way Doherty amplifiers. IEEE Trans. Microw. Theory Tech., 55 (5) (2007), 866–879.CrossRefGoogle Scholar
[15]Hanington, G.; Chen, P.-F.; Asbeck, P.M.; Larson, L.E.: High-efficiency power amplifier using dynamic power-supply voltage for CDMA applications. IEEE Trans. Microw. Theory Tech., 47 (8) (1999), 1471–1476.CrossRefGoogle Scholar
[16]Kim, J.; Cha, J.; Kim, I.; Kim, B.: Optimum operation of asymmetrical-cells-based linear Doherty power amplifiers — uneven power drive and power matching. IEEE Trans. Microw. Theory Tech., 53 (5) (2005), 1802–1809.Google Scholar
[17]Yang, Y.; Cha, J.; Shin, B.; Kim, B.: A microwave doherty amplifier employing envelope tracking technique for high efficiency and linearity. IEEE Microw. Wirel. Compon. Lett., 13 (9) (2003), 370–372.CrossRefGoogle Scholar
[18]Moon, J.; Kim, J.; Kim, I.; Kim, J.; Kim, B.: A wideband envelope tracking Doherty amplifier for WiMAX systems. IEEE Microw. Wirel. Compon. Lett., 18 (1) (2008), 49–51.CrossRefGoogle Scholar
[19]Colantonio, P.; Giannini, F.; Giofre, R.; Piazzon, L.: Theory and experimental results of a class F AB-C Doherty power amplifier. IEEE Trans. Microw. Theory Tech., 57 (8) (2009), 1936–1947.CrossRefGoogle Scholar
[20]Smith, K. J. I.; Eccleston, K. W.; Gough, P. T.; Mann, S. I.: The effect of FET soft turn-on on a Doherty amplifier. Microw. Opt. Technol. Dig., 50 (7) (2008), 1861–1864.CrossRefGoogle Scholar
[21]Kim, J.; Moon, J.; Woo, Y. Y.; Hong, S.; Kim, I.; Kim, B.: Analysis of a fully matched saturated Doherty amplifier with excellent efficiency. IEEE Trans. Microw. Theory Tech., 56 (2) (2008), 328–338.CrossRefGoogle Scholar
[22]Woo, Y.; Yang, Y.; Kim, B.: Analysis and experiments for high-efficiency class-F and inverse class-F power amplifiers. IEEE Trans. Microw. Theory Tech., 54 (5) (2006), 1969–1974.Google Scholar