FULLY DIFFERENTIAL CAPACITIVE ARCHITECTURE FOR MEMS ACCELEROMETER
First Claim
1. A method, comprising:
- detecting, by at least two pairs of capacitors within an apparatus, a change in the acceleration of the apparatus;
determining an acceleration of the apparatus based at least in part on the detecting.
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Accused Products
Abstract
A fully differential microelectromechanical system (MEMS) accelerometer configured to measure Z-axis acceleration is disclosed. This may avoid some of the disadvantages in traditional capacitive sensing architectures—for example, less sensitivity, low noise suppression, and low SNR, due to Brownian noise. In one embodiment, the accelerometer comprises three silicon wafers, fabricated with electrodes forming capacitors in a fully differential capacitive architecture. These electrodes may be isolated on a layer of silicon dioxide. In some embodiments, the accelerometer also includes silicon dioxide layers, piezoelectric structures, getter layers, bonding pads, bonding spacers, and force feedback electrodes, which may apply a force to the proof mass region. Fully differential MEMS accelerometers may be used in geophysical surveys, e.g., for seismic sensing or acoustic positioning.
28 Citations
20 Claims
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1. A method, comprising:
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detecting, by at least two pairs of capacitors within an apparatus, a change in the acceleration of the apparatus; determining an acceleration of the apparatus based at least in part on the detecting. - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus, comprising:
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a first substrate; first and second spring layers respectively disposed on a first surface and a second, opposite surface of the first substrate; first and second sets of electrodes respectively disposed on the first and second spring layers; a second substrate spaced from the first spring layer, wherein a third set of electrodes are disposed on the second substrate at locations corresponding to those of the first set of electrodes; and a third substrate spaced from the second spring layer, wherein a fourth set of electrodes are disposed on the third substrate at locations corresponding to those of the second set of electrodes. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. An apparatus, comprising:
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a central substrate region; a first bonded substrate opposing a first surface of the central substrate region; a second bonded substrate opposing a second surface of the central substrate region; a first pair of capacitors formed between the first bonded substrate and the central substrate region; and a second pair of capacitors formed between the second bonded substrate and the central substrate region. - View Dependent Claims (14, 15, 16, 17, 18)
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19. An apparatus, comprising:
a fully differential MEMS accelerometer configured to measure Z-axis acceleration of a proof mass. - View Dependent Claims (20)
Specification