Analog Devices,inc.

Analod Devices, Inc.

John Albert Geen

William Albert Clark

Donald W Carow

Jinbo Kuang

Igor P Prikhodko

Michael W Judy

Vineet Kumar

John R Martin

Jeffrey A Gregory

Steven J Sherman

Edward L Wolfe

Houri Johari-Galle

A Paul Brokaw

Geoffrey Thomas Haigh

Lawrence E Felton

Harvey Weinberg

Chau Cuong Tran

Gaurav Vohra

Kenneth Flanders

George M Molnar

Kevin H-l Chau

Gregory S Davis

Bruce Ma

Kenneth J Cole

James Timony

John F Chang

John Chang

According to some aspects, there is provided a microelectromechanical systems (MEMS) device wherein one or more components of the MEMS device exhibit attenuated motion relative to one or more other moving components. The MEMS device may comprise a substrate; a proof mass coupled to the substrate and configured to move along a resonator axis; and a first shuttle coupled to the proof mass and comprising one of a drive structure configured to drive the proof mass along the resonator axis or a sense structure configured to move along a second axis substantially perpendicular to the resonator axis in response to motion of the proof mass along the resonator axis, wherein displacement of at least a first portion of the proof mass is attenuated relative to displacement of the first shuttle and/or a second portion of the proof mass.

Isotropic attenuated motion gyroscope

Micromachined inertial devices are presented having multiple linearly-moving masses coupled together by couplers that move in a linear fashion when the coupled masses exhibit anti-phase motion. The couplers move in opposite directions of each other, such that one coupler on one side of the movable masses moves in a first linear direction and another coupler on the opposite side of the movable masses moves in a second linear direction opposite the first linear direction. The couplers ensure proper anti-phase motion of the masses.

Balanced runners synchronizing motion of masses in micromachined devices

Synchronized mass gyroscope

Thick (i.e., greater than two microns), fine-grained, low-stress tungsten MEMS structures are fabricated at low temperatures, particularly for so-called 'MEMS last' fabrication processes (e.g., when MEMS structures are fabricated after electronic circuitry is fabricated). Means for very accurately etching structural details from the deposited tungsten layer and for strongly and stably anchoring the tungsten layer to an underlying substrate are disclosed. Also, means for removing a sacrificial layer underlying the mobile tungsten layer without damaging the tungsten or allowing it to be drawn down and stuck by surface tension is disclosed.

Fabrication of tungsten MEMS structures

A method of detecting motion provides a resonator having a mass, moves the mass in a translational mode, and actuates the mass in a given bulk mode. The mass moves in the translational and given bulk modes at substantially the same time and, accordingly, the resonator is configured to detect linear and rotational movement when moving and actuating the mass in the translational and given bulk modes. The method produces one or more movement signals representing the detected linear and rotational movement.

Method and apparatus for detecting linear and rotational movement

In comb drive vibratory gyroscopes, drive-induced Coriolis accelerometer offset is effectively canceled by demodulating the output during equal times of in-phase and anti-phase drive of the shuttle with respect to the velocity signal used for angular rate demodulation. This reduces or eliminates the corresponding thermal and die-stress effects otherwise needing calibration.

MEMS gyroscopes with reduced errors

A substrate for an inertial sensor system includes a plurality of electrode arrangements, each electrode arrangement including an acceleration sensor electrode and a pair of quadrature adjusting electrodes on opposite sides of the acceleration sensor electrode, where each electrode arrangement is capable of being overlaid by a corresponding plate of a shuttle such that the plate completely overlays the acceleration sensor electrode and partially overlays the pair of quadrature adjusting electrodes on opposite sides of the acceleration sensor electrode such that capacitive coupling between the plate and each of the quadrature adjusting electrodes is dependent upon the rotational position of the at least one shuttle while capacitive coupling between the plate and the acceleration sensor electrodes is substantially independent of the rotational position of the at least one shuttle.

Electrode arrangements for quadrature suppression in inertial sensors

One or more electrodes that interact with a movable mass in a MEMS device are anchored or otherwise supported from both the top and bottom and optionally also from one or more of the lateral sides other than the transduction side (i.e., the side of the electrode facing the mass) in order to severely restrict movement of the electrodes such as from interaction with the mass and/or external forces.

Apparatus and method for anchoring electrodes in MEMS devices

Bulk acoustic wave (BAW) gyroscopes purposefully operate using non-degenerate modes, i.e., resonant frequencies of drive and sense modes are controlled so they are not identical. The resonant frequencies differ by a small controlled amount (&#x394;f). The difference (&#x394;f) is selected such that the loss of sensitivity, as a result of using non-degenerate modes, is modest. Non-degenerate operation can yield better bandwidth and improves signal-to-noise ratio (SNR) over comparable degenerate mode operation. Increasing Q of a BAW resonator facilitates trading bandwidth for increased SNR, thereby providing a combination of bandwidth and SNR that is better than that achievable from degenerate mode devices. In addition, a split electrode configuration facilitates minimizing quadrature errors in BAW resonators.

Non-degenerate mode MEMS gyroscope

Error sources relating to the drive signal applied to the resonator of an inertial sensor, such as in-phase offset errors relating to the drive signal and/or electronic pass-through of the drive signal to accelerometer sense electronics, are detected by modulating the drive signal and sensing accelerometer signals that are induced by the modulated drive signal. Error sources related to aerodynamics of an inertial sensor resonator are detected by modulating the distance between the resonator and the underlying substrate and sensing accelerometer signals that are induced by such modulation. Compensating signals may be provided to substantially cancel errors caused by such error sources.

Offset detection and compensation for micromachined inertial sensors

The transduction scale factor for a MEMS gyroscope is calibrated without moving the MEMS device based on measurements of the resonator resonance frequency and the accelerometer resonance frequency as well as a distance value that may be a fixed distance value or a measured distance value. The measured distance value may be obtained by measuring the quality factor of the resonator or accelerometer and deriving the measured distance value from the quality factor measurement.

Apparatus and method for calibrating MEMS inertial sensors

Error sources related to aerodynamics of an inertial sensor resonator are detected by modulating the distance between the resonator and the underlying substrate and sensing modulated error signals in the accelerometer that are induced by such modulation. Compensating signals may be provided to substantially cancel errors caused by such error sources.

Detection and mitigation of aerodynamic error sources for micromachined inertial sensors

In an inertial sensor having a resonator and an accelerometer, acceleration signals are induced by resonating at least one shuttle of the resonator in a device plane at a shuttle resonance mode frequency and modulating the motion of the at least one resonator shuttle to induce accelerometer signals from the accelerometer. The motion may be modulated in the device plane or out of the device plane. A shuttle resonance mode and an accelerometer resonance mode may me matched based on the induced accelerometer signals, for example, by providing a feedback signal to the inertial sensor in response to such induced accelerometer signals to substantially nullify the induced accelerometer signals.

Mode-matching apparatus and method for micromachined inertial sensors

Detecting and/or mitigating the presence of particle contaminants in a MEMS device involves converting benign areas in which particles might become trapped undetectably by electric fields during test to field-free regions by extending otherwise non-functional conductive shield and gate layers and placing the same electrical potential on the conductive shield and gate layers. Particle contaminants can then be moved into detection locations remote from the potential trap areas and having particle detection structures by providing some mechanical disturbance.

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Tewksbury, MA, United States of America

John Albert Geen