A comparison of npn vs. pnp SiGe HBT oscillator phase noise performance in a complementary SiGe platform

Author

Horst, Stephen J. ; Chakraborty, Partha ; Saha, Prabir ; Cressler, John D. ; Gustat, Hans ; Heinemann, Bernd ; Fischer, Gerhard G. ; Knoll, Dieter ; Tillack, Bernd

Author_Institution

Sch. of ECE, Georgia Tech, Atlanta, GA, USA

fYear

2010

Firstpage

13

Lastpage

16

Abstract

A comparison of cross-coupled oscillator performance is presented for a high-speed, complementary SiGe (C-SiGe = npn + pnp) BiCMOS platform with matched npn and pnp performance. Results show with all factors held constant, the pnp-only VCO design holds an advantage in white FM phase noise over its npn counterpart at constant current; a counter-intuitive outcome if one only considers absolute base resistance. The reduced noise in the pnp-only VCO is shown to stem from the device´s decreased β compared to the npn, which reduces conversion of the thermal noise associated with the base resistance to the output node. Understanding this phase noise reduction effect has potential to influence oscillator device selection in any given technology family.

Keywords

BiCMOS integrated circuits; Ge-Si alloys; heterojunction bipolar transistors; phase noise; semiconductor materials; SiGe; SiGe HBT oscillator phase noise performance; base resistance; complementary SiGe platform; cross-coupled oscillator performance; high-speed complementary SiGe BiCMOS platform; oscillator device selection; phase noise reduction; pnp-only VCO design; thermal noise; white FM phase noise; Heterojunction bipolar transistors; Phase noise; Resonant frequency; Silicon germanium; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Bipolar/BiCMOS Circuits and Technology Meeting (BCTM), 2010 IEEE

Conference_Location

Austin, TX

ISSN

1088-9299

Print_ISBN

978-1-4244-8578-9

Type

conf

DOI

10.1109/BIPOL.2010.5667989

Filename

5667989