High-Power Amplifier Linearization Using the Doherty Amplifier as a Predistortion Circuit

Author

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

Author_Institution

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

Volume

18

Issue

9

fYear

2008

Firstpage

611

Lastpage

613

Abstract

This paper presents the application of a Doherty power amplifier (DPA) as a predistortion circuit for the linearization of high PA. When the DPA is employed as the driver amplifier, its nonlinearity is used as predistorted components to cancel the strong nonlinearity of the main amplifier. To verify the proposed method, the DPA is implemented with two 30-W silicon metal-oxide semiconductor field-effect transistors and tested with a 180-W main amplifier at a 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 third- and fifth-order intermodulation (IM3 and IM5) components and a superior adjacent channel leakage ratio improvement are achieved.

Keywords

MOSFET circuits; UHF amplifiers; code division multiple access; driver circuits; linearisation techniques; power amplifiers; Doherty amplifier; Doherty power amplifier; driver amplifier; frequency 2.14 GHz; high-power amplifier linearization; main amplifier; power 180 W; power 30 W; predistortion circuit; silicon metal-oxide semiconductor field-effect transistors; wideband code-division multiple access band; Broadband amplifiers; Circuit testing; Driver circuits; FETs; High power amplifiers; MOS devices; Multiaccess communication; Predistortion; Semiconductor device testing; Silicon; Doherty amplifier; intermodulation distortion (IMD); linearity; power amplifier (PA); predistortion; wideband code-division multiple access (WCDMA);

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2008.2002461

Filename

4624623