On the phase-noise and phase-error performances of multiphase LC CMOS VCOs

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This paper presents an analysis of phase noise in multiphase LC oscillators, and measurement results for several CMOS quadrature-voltage-controlled-oscillators (QVCOs) working in the 2-GHz frequency range. The phase noise data for a so-called BS-QVCO (-140 dBc/Hz or less at 3 MHz frequency offset from the carrier, for a power consumption of 20.8 mW and a figure-of-merit of 184 dBc/Hz) show that phase noise performances are close to the previously derived limits. A systematic cause of departure from ideal quadrature between QVCO signals is also analyzed and measured experimentally, and a compact LC-tank layout that removes this source of phase error is proposed. A TS-QVCO designed with this technique shows a phase-noise figure-of-merit improvement of 4 dB, compared to a previous implementation. The measured equivalent phase error for all QVCOs is between 0.6/spl deg/ and 1/spl deg/.


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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Electrical Engineering, Electronic Engineering, Information Engineering
Original languageEnglish
Pages (from-to)1883-1893
JournalIEEE Journal of Solid-State Circuits
Issue number11
Publication statusPublished - 2004
Publication categoryResearch
Externally publishedYes