Design of high-efficiency RF Class-D power amplifier

Author

El-Hamamsy, Sayed-Am

Author_Institution

Gen. Electr. Corp. Res. & Dev. Center, Schenectady, NY, USA

Volume

9

Issue

3

fYear

1994

fDate

5/1/1994 12:00:00 AM

Firstpage

297

Lastpage

308

Abstract

In this paper, the losses in a Class-D RF switching power amplifier and their frequency dependence are described. The losses analyzed are the switching, conduction, and gate drive losses. A 300 W, 13.56 MHz, Class-D circuit is designed in the traditional manner to illustrate the magnitude of the different types of loss. A circuit using the ZVS equations developed in this paper is designed. An experimental circuit is built using standard IRF540 devices in TO220 packages. That circuit does not meet its performance goals because of the package inductance. A new low inductance half-bridge package is introduced to solve this problem. Techniques for circuit layout and power measurements for RF applications are also presented in the experimental section. A low loss gate drive circuit is also presented using a Class-E circuit to provide the drive power. The experimental results confirm the accuracy of the design equations derived in this paper

Keywords

bridge circuits; circuit layout; inductance; losses; power amplifiers; power measurement; radiofrequency amplifiers; switching; 13.56 MHz; 300 W; Class-E circuit; IRF540 devices; RF Class-D power amplifier; TO220 packages; ZVS equations; circuit layout; conduction losses; drive power; frequency dependence; gate drive losses; high-efficiency; low inductance half-bridge package; low loss gate drive circuit; package inductance; power measurements; switching losses; Circuits; Equations; Frequency dependence; High power amplifiers; Inductance; Packaging; Power amplifiers; Radio frequency; Radiofrequency amplifiers; Zero voltage switching;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/63.311263

Filename

311263