Emitter-ballasting-resistor-free SiGe microwave power heterojunction bipolar transistor

Author

Jinshu Zhang ; Hongyong Jia ; Pei-Hsin Tsien ; Tai-Chin Lo

Author_Institution

Inst. of Microelectron., Tsinghua Univ., Beijing, China

Volume

20

Issue

7

fYear

1999

fDate

7/1/1999 12:00:00 AM

Firstpage

326

Lastpage

328

Abstract

The emitter ballasting resistor is used to equalize the current distribution between the emitter stripes in power transistor, but it will degrade the output power, power gain, and power added efficiency. Experimental results indicate that the current gain of uniform-base SiGe heterojunction bipolar transistors (HBTs) decreases with the increase of the temperature above 160 K, so the current distribution is equalized by itself to some extent. Therefore, the microwave power SiGe HBTs without emitter ballasting resistor were fabricated for the first time, and the continuous output power of 5 W and power added efficiency of 63% were obtained under Class C operation at a frequency of 900 MHz. Hence, the emitter current density of the SiGe HBT´s with emitter width of 6 μm is 0.79 A/cm.

Keywords

Ge-Si alloys; current density; heterojunction bipolar transistors; microwave bipolar transistors; power bipolar transistors; semiconductor materials; 5 W; 6 micron; 63 percent; 900 MHz; Class C operation; SiGe; current gain; emitter current density; microwave power heterojunction bipolar transistor; output power; power added efficiency; power gain; Current distribution; Degradation; Electronic ballasts; Germanium silicon alloys; Heterojunction bipolar transistors; Power generation; Power transistors; Resistors; Silicon germanium; Temperature distribution;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.772365

Filename

772365