Phase jitter in an oscillator is also often referred to as timing jitter. When the signal approaches the oscillation frequency, the phase noise level generally increases in an electronic oscillator. The RMS phase jitter for an oscillator is a time measurement expressed in picoseconds (pSec) and refers to how phase jitter is calculated from phase noise. Within an oscillator, the phase noise components move the device signal to adjacent frequencies, which produces various noise sidebands. The phase noise from an oscillator usually includes white noise and lower-frequency flicker noise.
