Salvatore Levantino

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A new concept for quadrature coupling of oscillators is introduced and demonstrated on a 5-GHz CMOS voltagecontrolled oscillator (VCO). It uses the second harmonic of the outputs to couple the oscillators. The technique provides quadrature over a wide tuning range without introducing any increase in phase noise or power consumption. The VCO is tunable(More)
This paper proposes a complete analysis of quadrature-coupled LC oscillators. These oscillators operate off-resonance and for this reason, their phase noise worsens at increasing coupling strength. Since the coupling transistors raise the total power consumption, the noise-power product degrades further with respect to a stand-alone oscillator. On the other(More)
In digital bang-bang phase-locked loops (BBPLLs), both the hard nonlinearity of the phase detector and the frequency granularity of the digitally controlled oscillator (DCO) can give rise to undesired tones or peaking in the output spectrum. This work derives the maximum ratio between DCO resolution and jitter, which avoids limit cycles, in the case of(More)
Flicker noise up-conversion in voltage-biased oscillators can be effectively suppressed by inserting resistances in series to the drain of the transconductor MOSFETs. This solution avoids the degradation of the start-upmargin and the adoption of area-demanding resonant filters with proper tuning. This paper presents a detailed theoretical analysis of 1/f(More)