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—A new concept for quadrature coupling of oscil-lators is introduced and demonstrated on a 5-GHz CMOS voltage-controlled 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)
—Flicker noise up-conversion in voltage-biased oscilla-tors can be effectively suppressed by inserting resistances in series to the drain of the transconductor MOSFETs. This solution avoids the degradation of the start-up margin and the adoption of area-demanding resonant filters with proper tuning. This paper presents a detailed theoretical analysis of 1/f(More)
This paper describes an original computational procedure to extract the perturbation projection vector of oscillators by means of a frequency domain technique. A key feature of the method is that it relies on the periodic transfer function analysis, which is available in most circuit simulators, and thus it can easily be exploited by oscillator designers.(More)