A study of Class C operation of GaAs power HBTs

Author

Ali, Farahiyah ; Gupta, Arpan ; Salib, M. ; Veasel, B.

Author_Institution

Adv. Technol. Div., Westinghouse Electr. Corp., Baltimore, MD, USA

fYear

1995

fDate

16-20 May 1995

Firstpage

721

Abstract

GaAs power HBTs are traditionally biased in Class A or Class AB mode for power amplifiers. This paper describes the tradeoffs of operating these devices in Class C bias. We find that power-added efficiency (PAE) improves and power gain decreases in Class C when compared to Class AB bias. At 6 GHz, the PAE increased by greater than 10 percentage points (from 68.9% in Class AB to 80.6% in Class C) with concurrent loss of 4.3 dB in power gain. The efficiency improves monotonically with lower operating frequency. In a single-tone environment, the second harmonic increases by /spl sim/7 dB in Class C over Class AB. To our knowledge, this is the first report on the experimental study of Class C operation of GaAs HBTs.<>

Keywords

III-V semiconductors; gallium arsenide; heterojunction bipolar transistors; microwave bipolar transistors; microwave power transistors; power bipolar transistors; semiconductor device testing; 4.3 dB; 6 GHz; 80.6 percent; GaAs; class C operation; power HBTs; power amplifiers; power gain; power-added efficiency; second harmonic; single-tone environment; Breakdown voltage; Fingers; Gallium arsenide; Heterojunction bipolar transistors; MESFETs; Power amplifiers; Power supplies; Radio frequency; Radiofrequency amplifiers; Tuners;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 1995., IEEE MTT-S International

Conference_Location

Orlando, FL, USA

ISSN

0149-645X

Print_ISBN

0-7803-2581-8

Type

conf

DOI

10.1109/MWSYM.1995.406006

Filename

406006