Method and apparatus for measuring the resonant frequency of a high Q resonator

摘要

A resonator is initially charged by applying a drive signal offset from the expected resonant frequency of the resonator for a selected period of time. After the drive signal is removed from the resonator a period counter is used to count the period of the output signal of the resonator as it rings down. For low-Q resonators an amplifier is included to amplify the resonator output signal before being applied to the period counter to increase the number of cycles of that signal which are within the dynamic range of the period counter.