Low phase noise differential LC tank VCO with current...

Details Low phase noise differential LC tank VCO with current... Low phase noise differential LC tank VCO with current...

2006-09-11

2008-08-19

Chang, Joseph (Department: 2817)

Oscillators

L-c type oscillators

C331S1170FE

Reexamination Certificate

active

07414488

ABSTRACT:
A differential voltage controlled oscillator (VCO) employed in a frequency synthesizer used as a local oscillator of a wireless communication on-chip transmitter/receiver is provided. More particularly, a differential current negative feedback VCO equipped with a current-current negative feedback circuit that suppresses low- and high-frequency noise is provided.A differential current negative feedback VCO includes a resonator determining oscillation frequency, and an oscillator generating negative resistance. In the oscillator of the differential current negative feedback VCO, transistors Q1and Q2form a cross-coupled pair, and negative resistance is generated by positive feedback of the cross-coupled pair. And, transistors Q1and Q3together with an emitter resistor and a capacitor form a current negative feedback part, and transistors Q2and Q4together with an emitter resistor and a capacitor form another current negative feedback part which is disposed opposite to a resonator. Thus, the VCO operates differentially.In the oscillator of the differential current negative feedback VCO, emitter noise currents generated by base noise voltages of Q1and Q2induced by low- and high-frequency noise sources in the bases of Q1and Q2are sampled by emitter resistors, amplified through bases of Q3and Q4, and thus return to the bases of the Q1and Q2and suppress the base noise voltages. Measurement of the phase noise of the differential current negative feedback VCO reveals a phase noise reduction of approximately 25 dB compared to a conventional differential VCO.

REFERENCES:
patent: 4169248 (1979-09-01), Hongu et al.
patent: 5379003 (1995-01-01), Bizen
patent: 6198359 (2001-03-01), Wichern
patent: 6466099 (2002-10-01), Festag
patent: 2002/0113659 (2002-08-01), Scoggins
patent: 2020000018545 (2000-10-01), None
patent: 1020030026123 (2003-03-01), None
patent: 1020030070576 (2003-08-01), None
Ja-Yol Lee et al.; “A Low-Phase Noise 5-GHz CCNF Colpitts VCO with Parallel Branch Inductors”; Proceedings of the 2005 Bipolar/BiCMOS Circuits and Technology Meeting; IEEE Catalog No. 05CH37709C; pp. 240-243.
Ulrich L. Rohde; Nonlinear Effects In Oscillators and Synthesizers (Invited); 2001 IEEE MTT-S Digest; pp. 689-692.
Kyung-Whan Yeom; “Design and fabrication of the surface mountable VCO operating at 3V for PCS handset”; Korean Institute of Communication and Sciences, '96-3 vol. 21, No. 3; pp. 784-794.

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