A time-variant analysis of the 1/f^(2) phase noise in CMOS parallel LC-Tank quadrature oscillators

Pietro Andreani

    Research output: Contribution to journalJournal articleResearchpeer-review

    823 Downloads (Pure)


    This paper presents a study of 1/f2 phase noise in quadrature oscillators built by connecting two differential LC-tank oscillators in a parallel fashion. The analysis clearly demonstrates the necessity of adopting a time-variant theory of phase noise, where a more simplistic, time-invariant approach fails to explain numerical simulation results even at the qualitative level. Two topologies of 5-GHz parallel quadrature oscillators are considered, and compact but nevertheless highly general, closed-form formulas are derived for the phase noise caused by the losses in the LC-tanks and by the noisy currents in the MOS transistors. A large number of spectreRF simulations, covering a wide range of working conditions for the oscillators, is used to validate the theoretical analysis.
    Original languageEnglish
    JournalI E E E Transactions on Circuits and Systems Part 1: Regular Papers
    Issue number8
    Pages (from-to)1749-1760
    Publication statusPublished - 2006

    Bibliographical note

    Copyright: 2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE


    • CMOS
    • LC-tank
    • oscillators
    • phase noise
    • quadrature


    Dive into the research topics of 'A time-variant analysis of the 1/f^(2) phase noise in CMOS parallel LC-Tank quadrature oscillators'. Together they form a unique fingerprint.

    Cite this