Browse > Article

Thermal Memory Effect Modeling and Compensation in Doherty Amplifier  

Lee Suk-Hui (Dept. of Electroics Eng.,Dankook University)
Lee Sang-Ho (Dept. of Electroics Eng.,Dankook University)
Bang Sung-Il (Dept. of Electroics Eng.,Dankook University)
Publication Information
Journal of the Institute of Electronics Engineers of Korea TC / v.42, no.9, 2005 , pp. 49-56 More about this Journal
Abstract
Memory effect, which influence the performance of Doherty amplifier, become more significant and critical in designing these circuits as the modulation signal bandwidth and operation power level increase. This paper reports on an attempt to investigate, model and quantity the contribution of the electrical nonlinearity effects and the thermal memory effects to a Doherty amplifier's distortion generation. Also this raper reports on the development of an accurate dynamic expression of the instantaneous junction temperature as a function of the instantaneous dissipated power. This expression has been used in the construction of an electrothermal model for the Doherty amplifier. Parameters for the nelv proposed behavior model were determined from the Doherty amplifier measurements obtained under different excitation conditions. This study led us to conclude that the effects of the transistor self-heating phenomenon are important for signals with wideband modulation bandwidth(ex. W-CDMA or UMTS signal). Doherty amplifier with electrothermal memory effect compensator enhanced ACLR performance about 20 dB than without electrothemal memory effect compensator. Experiment results were mesured by 60W LDMOS Doherty amplifier and electrothermal memory effect compensator was simulated by ADS.
Keywords
Behavior model; distortion; electro thermal; memory effect; Doherty amplifier;
Citations & Related Records
연도 인용수 순위
  • Reference
1 A. Rabany, L. Nguyen, and D. Rice, 'Memory effect reduction for LDMOS bias circuits,' Microwave J, pp. 124-130, Feb. 2003
2 J. H. K. Vuolevi, T. Rahkonen, and J. P. A. Manninen, 'Measurement technique for characterizing memory effects in RF power amplifiers, ' IEEE Trans. Microwave Theory Tech, col. 49, pp. 1383-1389, Aug. 2001   DOI
3 W. Bosch and G. Gatti, ' Measurement and simulation of memory effects in predistortion linearizers,' IEEE Trans. Microwave Theory Tech, vol. 37, pp. 1885-1890, Dec. 1989   DOI
4 Y. Youngoo, Y. Jeahyok, N. Joongjin, K. Bumman, and P. Myungkyu, 'Measurement of two-tone transfer characteristics of high-power amplifiers,' IEEE Trans. Microwave Theory Tech, vol. 49, pp. 568-571, Mar. 2001   DOI
5 J.S .Kenny, W. Woo, L. Ding, R. Raich, and T. Zhou 'The impact of memory effects on predistortion linearization of RF power amplifier' in 8th Int. Microwave and Optical Technology Symp., Montreal, QC, Canada, June 2001, pp. 189-193
6 S. Boumaiza and F. M. Ghannouchi, 'Realistic power-amplifiers characterization with application to baseband digital predistortion for 3G base stations,' IEEE Trans. Microwave Theory Tech, vol.50, pp.3016-3021, Dec. 2002   DOI