Application of Doherty Amplifier as a Predistortion Circuit for High Power Amplifier Linearization

Author

Lee, Yong-Sub ; Lee, Mun-Woo ; Jeong, Yoon-Ha

Author_Institution

Dept. of Electron. & Electr. Eng, Pohang Univ. of Sci. & Technol., Pohang

fYear

2008

fDate

27-31 Oct. 2008

Firstpage

1022

Lastpage

1025

Abstract

This paper presents the application of Doherty power amplifier (DPA) as predistortion circuit for linearization of high PA. When the DPA is employed to the driver amplifier, its nonlinearity is used as predistorted components to cancel the strong nonlinearity of the main amplifier. To verify proposed method, the DPA is implemented with two 30-W Si LDMOSFETs and teseted with a 180-W main amplifier at wideband code division multiple access (WCDMA) band of 2.14 GHz. For a two-tone signal with 2-MHz tone spacing and a one-carrier WCDMA signal, the significant cancellation of the 3rd and 5th-order intermodulation (IM3 and IM5) components and a superior adjacent channel leakage ratio (ACLR) improvement are achieved.

Keywords

MOSFET circuits; UHF amplifiers; code division multiple access; intermodulation distortion; linearisation techniques; power amplifiers; Doherty amplifier; LDMOSFET; UHF amplifiers; adjacent channel leakage ratio; driver amplifier; frequency 2.14 GHz; intermodulation cancellation; power 180 W; power 30 W; power amplifier linearization; predistortion circuit; wideband code division multiple access; Broadband amplifiers; Driver circuits; High power amplifiers; Linearity; Microwave amplifiers; Microwave circuits; Multiaccess communication; Power amplifiers; Predistortion; Repeaters;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Conference, 2008. EuMC 2008. 38th European

Conference_Location

Amsterdam

Print_ISBN

978-2-87487-006-4

Type

conf

DOI

10.1109/EUMC.2008.4751630

Filename

4751630