Parametric amplification of a MEMS gyroscope by capacitance modulation
First Claim
1. A method for operating a Micro-Electro-Mechanical Systems (MEMS) gyroscope sensor, comprising:
- inducing a motor motion to a proof mass, the proof mass capacitively coupled to a sense electrode via a gap between mating comb fingers of at least one comb finger pair that define a sense capacitance between the proof mass and the electrode, the shape of the sense electrode such that motion along the motor axis produces a variation in sense capacitance whereby the capacitance is variable as a function of a displacement in a position of the mated comb fingers caused by the induced motor motion; and
producing a time-varying electrical output in response to a rotation of the MEMS gyroscope, wherein the time-varying electrical output is amplified by the capacitance variation caused by the induced motor motion and the shape of the sense electrode.
3 Assignments
0 Petitions
Accused Products
Abstract
Parametric amplification of the output of a MEMS gyroscope is achieved by modulating the sense capacitance, or an auxiliary capacitance having an applied DC voltage. The capacitance modulation is produced by the driven motion of the gyroscope mechanism, so the pump signal of the parametric amplifier is not subject to phase errors in the electronics. The capacitance modulation affects the mechanical gain of the sensor (transfer function from input force to sensor mechanism displacement), as well as the electrical gain of the sensor (transfer function from sensor mechanism displacement to output electrical signal). The mechanical and electrical gains of the sensor become phase-dependent, so the Coriolis rate signal can be amplified while the unwanted quadrature-phase signal is attenuated.
-
Citations
18 Claims
-
1. A method for operating a Micro-Electro-Mechanical Systems (MEMS) gyroscope sensor, comprising:
-
inducing a motor motion to a proof mass, the proof mass capacitively coupled to a sense electrode via a gap between mating comb fingers of at least one comb finger pair that define a sense capacitance between the proof mass and the electrode, the shape of the sense electrode such that motion along the motor axis produces a variation in sense capacitance whereby the capacitance is variable as a function of a displacement in a position of the mated comb fingers caused by the induced motor motion; and producing a time-varying electrical output in response to a rotation of the MEMS gyroscope, wherein the time-varying electrical output is amplified by the capacitance variation caused by the induced motor motion and the shape of the sense electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A Micro-Electro-Mechanical Systems (MEMS) sensor, comprising:
-
a proof mass with at least one proof mass comb finger, the proof mass comb finger comprising; a proof mass comb finger end portion; and a proof mass comb finger attaching portion that couples the proof mass comb finger end portion to the proof mass; a sense electrode with at least one sense electrode comb finger separated from the proof mass comb finger by a gap, the gap defining a variable capacitive coupling between the proof mass comb finger and the sense electrode comb finger, the sense electrode comb finger comprising; a sense electrode comb finger end portion; and a sense electrode comb finger attaching portion that couples the sense electrode comb finger end portion to an anchor; an electrical output operable to output a time-varying electrical output, the time-varying electrical output being amplified by a variation of the variable capacitive coupling produced by an induced motor motion of the proof mass and the shape of the sense electrode, wherein the shape is such that the induced motor motion produces a variation in sense capacitance, whereby the variable output is amplified by the capacitance variation. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A sensor, comprising:
-
a proof mass with at least one proof mass comb finger, the proof mass comb finger comprising; a proof mass comb finger end portion; and a proof mass comb finger attaching portion that couples the proof mass comb finger end portion to the proof mass; a sense electrode with at least one electrode comb finger separated from the proof mass comb finger by a gap, the gap defining a variable capacitive coupling between the proof mass comb finger and the electrode comb finger, the electrode comb finger comprising; an electrode comb finger end portion; and an electrode comb finger attaching portion that couples the electrode comb finger end portion to an anchor; an electrical output operable to output a variable output in response to a variation of the variable capacitive coupling produced by an induced motor motion of the proof mass and the shape of the sense electrode, wherein the shape is such that the induced motor motion produces a variation in sense capacitance, whereby the variable output is amplified by the capacitance variation. - View Dependent Claims (18)
-
Specification