Frequency jumps on BVA and other precision quartz crystal resonators and burst-noise on overtone mode high-frequency quartz crystal resonators

Frequency jumps have been observed on BVA and other precision quartz crystal resonators/oscillators during prolonged and continuous operation. To date frequency-jump phenomena have not been well understood as these jumps have been designated as micro-jumps or abrupt frequency jumps irrespective of the nature of the jumps. In this paper, these frequency jumps will be classified into three distinct and separate categories and these are: (i) Intermittent Frequency Jumps, (ii) Discrete Frequency Jumps, and (iii) Abrupt Frequency Jumps. To characterise and distinguish these frequency jumps, apart from continuous and prolonged operation, other resonator/oscillator parameters, such as g-sens, retrace, drive-level-dependence, bandbreaks (i.e., dips), phase-noise etc. have also to be measured. Intermittent and discrete frequency jumps can be correlated to one or more resonator/oscillator parameter. Finally burst-noise observed on overtone-mode high-frequency quartz crystal resonators will be reviewed and explanations will be given to demonstrate why this noise process cannot be correlated to known crystal resonator parameter variations. As in the case of abrupt frequency jump, a new resonator model is required to explain this burst-noise phenomenon