AlGaAs/GaAs HBT linearity characteristics

Author

Wang, Nan Lei ; Ho, Wu Jing ; Higgins, J.A.

Author_Institution

Sci. Center, Rockwell Int. Corp., Thousand Oaks, CA, USA

Volume

42

Issue

10

fYear

1994

fDate

10/1/1994 12:00:00 AM

Firstpage

1845

Lastpage

1850

Abstract

Communication systems require linear power amplifiers with high efficiency and very low intermodulation distortion. AlGaAs/GaAs heterojunction bipolar transistors (HBT´s) were found to have very low intermodulation distortion in power operation. Two-tone tests were carried out on both common-emitter (CE) and common-base (CB) power HBT´s. At 7 GHz, the CE HBT showed -20 dBc IM₃ (third-order intermodulation ratio) and 12% power added efficiency (PAE) per tone at the 1 dB gain compression point; IM₃ dropped to -30 dBc at 1.5 dB output power backoff. The CE HBT has lower intermodulation distortion than CB HBT. Load pull data were collected to aid the understanding of the intermodulation. Parameters of the Gummel-Poon model (as used in SPICE) were derived for HBT´s based on dc data and small-signal S parameters at various bias points. The accuracy and validity of the model were confirmed by comparison to experimental two-tone results. SPICE predicts that the emitter and base resistances linearize the HBT and reduce the third-order intermodulation distortion. The excellent third-order intermodulation performance of the CE HBT makes it a very attractive choice for linear power amplifiers

Keywords

III-V semiconductors; S-parameters; aluminium compounds; gallium arsenide; heterojunction bipolar transistors; intermodulation; microwave amplifiers; power amplifiers; power transistors; semiconductor device models; solid-state microwave devices; 12 percent; 7 GHz; AlGaAs-GaAs; AlGaAs/GaAs; Gummel-Poon model; HBT; common-base configuration; common-emitter configuration; intermodulation distortion; linear power amplifiers; linearity characteristics; power added efficiency; small-signal S parameters; third-order intermodulation performance; two-tone tests; Gain; Gallium arsenide; Heterojunction bipolar transistors; High power amplifiers; Intermodulation distortion; Linearity; Power generation; SPICE; Scattering parameters; Testing;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.320763

Filename

320763