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On the oscillation limits of HBT cross-coupled oscillators

Published online by Cambridge University Press:  16 February 2012

Atheer Barghouthi
Affiliation:
Chair for Circuit Design and Network Theory, Dresden University of Technology, Helmholzstrasse 18, 01069 Dresden, Germany. Phone: +49 351 463 32702
Corrado Carta
Affiliation:
Chair for Circuit Design and Network Theory, Dresden University of Technology, Helmholzstrasse 18, 01069 Dresden, Germany. Phone: +49 351 463 32702
Udo Jörges
Affiliation:
Chair for Circuit Design and Network Theory, Dresden University of Technology, Helmholzstrasse 18, 01069 Dresden, Germany. Phone: +49 351 463 32702
Frank Ellinger*
Affiliation:
Chair for Circuit Design and Network Theory, Dresden University of Technology, Helmholzstrasse 18, 01069 Dresden, Germany. Phone: +49 351 463 32702
*
Corresponding author: F. Ellinger Email: frank.ellinger@tu-dresden.de

Abstract

In evaluating the potential of a given integrated-circuit technology, the negative conductance approach is used to estimate a maximum frequency limit for the ability of Heterojunction Bipolar Transistor (HBT) cross-coupled architecture to function as an oscillator at high frequencies. In this paper, the simple low-frequency estimation of the negative conductance, commonly used in the literature, is extended by deriving a new expression that takes into account the HBT parasitics. An expression for the frequency at which the negative conductance of the circuit crosses zero is given, which gives maximum frequency of oscillation for an ideal tank (no tank losses). In addition, the effect of the feedback capacitor, which is commonly added for direct current (DC) decoupling and boosting the negative conductance, is analyzed and new insight on the choice of the value of this capacitance is introduced. The results were proven by simulations using SiGe HBT transistors with an ft of 190 GHz.

Type
Research Papers
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2012

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References

REFERENCES

[1]Hajimiri, A.; Lee, T.: A general theory of phase noise in electrical oscillators. IEEE J. Solid-State Circuits, 33 (2) (1998), 179194.CrossRefGoogle Scholar
[2]Barghouthi, A.; Ellinger, F.: Design of a 54 to 63 GHz differential common collector SiGe colpitts VCO, in Proc. IEEE Conf. on Microwave, Radar, and Wireless Communications, MIKON, Vilnius, Lithuania, 2010, 120123.Google Scholar
[3]Li, H.; Rein, H.: Millimeter-wave VCOs with wide tuning range and low phase noise, fully integrated in a SiGe bipolar production technology. IEEE J. Solid-State Circuits, 33 (8) (2003), 184190.CrossRefGoogle Scholar
[4]Mansour, Ma.; Mansour, Mo.; Mehorta, A.: Analysis of MOS cross-coupled LC-Tank oscillators using short-channel device equations, in Proc. IEEE Design Automation Conf, CA, USA, October 2004.Google Scholar
[5]Ellinger, F.: Radio Frequency Integrated Circuits, 2nd ed., Springer, Berlin, Heidelberg, Germany, 2007.Google Scholar
[6]Rogers, J.; Plett, C.: Radio Frequency Integrated Circuit Design, 1st ed., Artech House, Norwood, MA, USA, 2003.Google Scholar
[7]Jeong, Y.; Choi, S.; Yang, K.: Performance Improvements of InP-based differential HBT VCO using the resonant tunneling diode, in Proc. IEEE Conf. on Indium Phosphide and Related Materials, NJ, USA, 2006, 4245.Google Scholar