Design and Linearization of Class-E Power Amplifier for Nonconstant Envelope Modulation

Author

Chen, Chi-Tsan ; Li, Chien-Jung ; Horng, Tzyy-Sheng ; Jau, Je-Kuan ; Li, Jian-Yu

Author_Institution

Dept. of Electr. Eng., Nat. Sun Yat-sen Univ., Kaohsiung

Volume

57

Issue

4

fYear

2009

fDate

4/1/2009 12:00:00 AM

Firstpage

957

Lastpage

964

Abstract

This paper presents design and linearization techniques for a highly efficient, but nonlinear Class-E power amplifier (PA) applied to linear RF transmitters. To achieve maximum efficiency for Class-E PA operating above gigahertz frequencies, the proposed design theory modifies the classic Class-E condition and considers switch-on and switch-off resistances in deriving the analytical solution. For linearization, a digital envelope predistorter (DEP) is used to provide predistorted envelope modulation for the RF-input and supply-voltage signals fed to the Class-E PA. This DEP can successfully compensate for AM/AM and AM/PM distortions such that the Class-E PA, although classified as a switching-mode PA, can act as a linear PA. A cdma2000 1 times transmitter incorporating this Class-E PA and DEP is demonstrated to simultaneously achieve high efficiency and high modulation quality.

Keywords

code division multiple access; network synthesis; power amplifiers; radio transmitters; radiofrequency amplifiers; cdma2000; class-E power amplifier design; digital envelope predistorter; linear RF transmitters; linearization techniques; nonconstant envelope modulation; supply-voltage signals; switch-off resistance; switch-on resistance; switching-mode PA; PA linearization techniques; cdma2000 1 $times $ transmitter; class-E power amplifier (PA); digital predistorter;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2009.2014444

Filename

4799230