A gate-modulated CMOS LC quadrature VCO

Kuang-Wei Cheng, David J. Allstot

Research output: Chapter in Book/Report/Conference proceedingConference contribution

20 Citations (Scopus)


A quadrature voltage-controlled oscillator (QVCO) based on the time-varying gate-modulated coupling of two LC tank VCOs is introduced. Using a standard 0.18μm CMOS process, the new topology is compared to the conventional series QVCO in terms of start-up loop gain, quadrature phase accuracy, phase noise, tuning range, and voltage headroom characteristics. In addition to comparable phase noise performance, the gate-modulated QVCO (GM-QVCO) also exhibits superior quadrature phase accuracy, and suitability for low power supply voltage designs that use cascode current sources and active loads. It draws 2.4 mA from a 1.8 V power supply, displays a phase noise of -122 dBc/Hz @ 1MHz offset, and has a quadrature phase error of 0.4°.

Original languageEnglish
Title of host publicationProceedings of the 2009 IEEE Radio Frequency Integrated Circuits Symposium, RFIC 2009
Number of pages4
Publication statusPublished - 2009 Oct 27
Event2009 IEEE Radio Frequency Integrated Circuits Symposium, RFIC 2009 - Boston, MA, United States
Duration: 2009 Jun 72009 Jun 9

Publication series

NameDigest of Papers - IEEE Radio Frequency Integrated Circuits Symposium
ISSN (Print)1529-2517


Other2009 IEEE Radio Frequency Integrated Circuits Symposium, RFIC 2009
Country/TerritoryUnited States
CityBoston, MA

All Science Journal Classification (ASJC) codes

  • Engineering(all)


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