Quality factor estimation for resonators
AssigneeAnalog Devices, Inc.
InventorsRonald A. Kapusta, Jiefeng Yan, James Lin
Life of this patent
Estimating the term…
Abstract
Various embodiments provide methods of determining the quality factor of a resonating body in ways that are advantageous over previously known methods. For example, embodiments allow the determination of the quality factors of a resonating body without preventing the simultaneous use of the resonating body. For micromachined (“MEMS”) devices, embodiments allow the determination of the quality factors of a resonating body in a manner that is not dependent on transduction parameters of the MEMS device.
Claims20
A method of estimating a quality factor of a resonator, the method comprising:
- driving the resonator between alternating ramp-up and ring-down phases, the ramp-up phases driven using a first drive signal for a first duration, the ring-down phases driven using a second drive signal for a second duration, wherein the first drive signal has a first amplitude and wherein the second drive signal has a second amplitude less than the first amplitude;
- making first and second measurements of a parameter associated with a resonance of the resonator;
- and
- producing an estimation of the quality factor of the resonator based on the first and second measurements.
Apparatus for estimating a quality factor of a resonator, the apparatus comprising:
- a driver circuit configured to drive the resonator between alternating ramp-up and ring-down phases, the ramp-up phases driven using the first drive signal for a first duration, the ring-down phases driven using a second drive signal for a second duration, wherein the first drive signal has a first amplitude and wherein the second drive signal has a second amplitude less than the first amplitude;
- and
- a quality factor measurement circuit configured to make first and second measurements of a parameter associated with a resonance of the resonator, the quality factor measurement circuit further configured to produce an estimation of the quality factor of the resonator based on the first and second measurements.
A MEMS gyroscope comprising:
- a resonator;
- a driver circuit configured to drive the resonator between alternating ramp-up and ring-down phases, the ramp-up phases driven using a first drive signal for a first duration, the ring-down phases driven using a second drive signal for a second duration, wherein the first drive signal has a first amplitude and wherein the second drive signal has a second amplitude less than the first amplitude;
- a quality factor measurement circuit configured to make first and second measurements of a parameter associated with a resonance of the resonator, the quality factor measurement circuit further configured to produce an estimation of a quality factor of the resonator based on the first and second measurements;
- and
- a gyroscope output circuit configured to sense rotation of the MEMS gyroscope based on Coriolis-induced signals.
Dependencies are inferred from the claim text.