Title :
Analysis and Design of a High-Efficiency Multistage Doherty Power Amplifier for WCDMA
Author :
Srirattana, N. ; Raghavan, A. ; Heo, D. ; Allen, P.E. ; Laskar, J.
Author_Institution :
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. Email: nsrirat@ece.gatech.edu, Tel: (404) 316-1177
Abstract :
A comprehensive analysis of multistage Doherty amplifier, which can be used to achieve higher efficiency at greater back-off compared to the classical Doherty amplifier, is presented. A novel set of design equations for a generalized N-stage Doherty amplifier is introduced. For the first time, this technique is applied to the design of a WCDMA power amplifier (PA). The designed PA meets WCDMA requirements, and exhibits a power-added efficiency (PAE) of 34.5% at 6 dB back-off and 16.9% at 12 dB back-off. These PAEs are 2 times and 4 times better, respectively, than that of a single stage linear PA at the same back-off levels. The PA is capable of delivering up to 28.6 dBm of output power, and has a maximum adjacent channel power leakage ratio of ¿38 dBc and ¿51 dBc at 5 and 10 MHz offset, respectively. To the best of the authors´ knowledge, these represent the best reported results of a Doherty amplifier for WCDMA application in the 1.95 GHz band, to date.
Keywords :
Communication systems; Design engineering; Energy consumption; Equations; High power amplifiers; Multiaccess communication; Power amplifiers; Power engineering and energy; Power engineering computing; Power generation;
Conference_Titel :
Microwave Conference, 2003 33rd European
Conference_Location :
Munich, Germany
Print_ISBN :
1-58053-834-7
DOI :
10.1109/EUMA.2003.340867
