Fully Integrated HBT MMIC Series-Type Extended Doherty Amplifier for W-CDMA Handset Applications

ETRI Journal

关键词: series-type Doherty amplifier;    predistorter;    MMIC;    integration;    extended Doherty concept;    Doherty amplifier;   

Others  :  1186006
DOI  :  10.4218/etrij.10.0209.0360

【 摘 要 】

A highly efficient linear and compactly integrated series-type Doherty power amplifier (PA) has been developed for wideband code-division multiple access handset applications. To overcome the size limit of a typical Doherty amplifier, all circuit elements, such as matching circuits and impedance transformers, are fully integrated into a single monolithic microwave integrated circuit (MMIC). The implemented PA shows a very low idle current of 25 mA and an excellent power-added efficiency of 25.1% at an output power of 19 dBm by using an extended Doherty concept. Accordingly, its average current consumption was reduced by 51% and 41% in urban and suburban environments, respectively, when compared with a class-AB PA. By adding a simple predistorter to the PA, the PA showed an adjacent channel leakage ratio better than -42 dBc over the whole output power range.

   

【 参考文献 】

• [1]J.F. Sevic "Statistical Characterization of RF Power Amplifier Efficiency for CDMA Wireless Communication Systems," Wireless Commun. Conf., 1997, pp. 110-113.
• [2]Y. Lee, M. Lee, and Y. Jeong, "Highly Linear and Efficient Microwave GaN HEMT Doherty Amplifier for WCDMA," ETRI J., vol. 30, no. 1, Feb. 2008, pp. 158-160.
• [3]J. Kim et al., Series-Type Doherty Amplifier without Hybrid Coupler, US Patent 7,164,316, Jan. 16, 2007.
• [4]C. Koo et al., "A Linearity Enhanced Compact Series-Type Doherty Amplifier Suitable for CDMA Handset Applications," IEEE Radio Wireless Symp., Jan. 2007, pp. 317-320.
• [5]M. Iwamoto et al., "An Extended Doherty Amplifier with High Efficiency over a Wide Power Range," IEEE Trans. Microw. Theory Tech., vol. 49, no. 12, Dec. 2001, pp. 2472-2479.
• [6]Y. Zhao et al., "Linearity Improvement of HBT-Based Doherty Power Amplifiers Based on a Simple Analytical Model," IEEE Trans. Microw. Theory Tech., vol. 54, no. 12, Dec. 2006, pp. 4479-4488.