Maximum efficiency and output of class-F power amplifiers

Author

Raab, Frederick H.

Author_Institution

Green Mountain Radio Res. Co., Colchester, VT, USA

Volume

49

Issue

6

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

1162

Lastpage

1166

Abstract

A class-F power amplifier (PA) improves efficiency and power-output capability (over that of class A) by using selected harmonics to shape its drain-voltage and drain-current waveforms. Typically, one waveform (e.g., voltage) approximates a square wave, while the other (e.g., current) approximates a half sine wave. The output power and efficiency of an ideal class-F PA can be related to the Fourier coefficients of the waveforms, and Fourier coefficients for maximally flat waveforms have been determined. This paper extends that theory by determining the coefficients for the maximum power and efficiency possible in a class-F PA with a given set of controlled harmonics

Keywords

UHF power amplifiers; harmonics; microwave power amplifiers; network analysis; Fourier coefficients; class-F power amplifiers; controlled harmonics; drain-current waveform shaping; drain-voltage waveform shaping; maximum efficiency; maximum power; power-output capability; Circuits; Helium; Impedance; Microwave frequencies; Power amplifiers; Power generation; Power system harmonics; Shape; Switches; Voltage;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.925511

Filename

925511