US 7,545,239 B2 · Serrated MEMS resonators

Abstract

One embodiment of the present invention sets forth a serrated tooth actuator for driving MEMS resonator structures. The actuator includes a fixed drive electrode having a serrated tooth surface opposing a MEMS resonator arm also having a serrated tooth surface, where the MEMS resonator arm is configured to rotate towards the drive electrode when an AC signal is applied to the drive electrode. Such a configuration permits higher amplitude signals to be applied to the drive electrode without the performance of the actuator being compromised by nonlinear effects. In addition, the serrated tooth configuration enables a sufficiently high actuating force to be maintained even though the distance traversed by the MEMS resonator arm during operation is quite small. Further, the serrated configuration allows a MEMS resonator system to withstand larger fluctuations in voltage and larger substrate stresses without experiencing a substantial shift in resonant frequency.

Claims22

Dependent claims

A microelectromechanical system (MEMS) for generating a timing signal, the system comprising:

a MEMS resonator including a first member aligned substantially parallel to a fist axis when stationary and having a serrated surface comprised of a first plurality of teeth;
a sense electrode aligned substantially parallel to the first axis and having a serrated surface comprised of a second plurality of teeth that opposes the serrated surface of the first member, wherein the teeth in the first plurality are interleaved with the teeth in the second plurality;
and
a drive electrode, wherein the first member is configured to rotate towards the sense electrode about a second axis that is perpendicular to the first axis in response to a signal being applied to the drive electrode,
wherein the teeth in the first plurality of teeth and the teeth in the second plurality of teeth have no surfaces substantially parallel to a third axis that is perpendicular to both the first axis and the second axis, and
wherein a capacitive change across each surface of a tooth in the first plurality of teeth and a corresponding surface of an opposing tooth in the second plurality of teeth results when the first member rotates towards the sense electrode.

3 more elements

Dependencies are inferred from the claim text.

Serrated MEMS resonators

Life of this patent

Serrated MEMS resonators

Life of this patent

Abstract

Claims22