ABSTRACT
In this chapter, the authors introduce a method to reduce a flicker noise upconversion in voltage-biased RF oscillators. Close-in spectra of RF oscillators are degraded by a flicker noise upconversion. The resulting low-frequency phase noise fluctuations can be mitigated as long as they fall within a loop bandwidth of an enclosing phase-locked loop. The authors show that when even-order harmonics of the tank current flow into the capacitive part of the tank, they distort the oscillation waveform by making its rise and fall times asymmetric and hence causing the noise upconversion. Odd-order harmonics also distort the oscillation waveform; however, the waveform in that case is still symmetric and will not result in the noise upconversion.
