Abstract: A sensor includes an acceleration or magnetic field sensitive microelectromechanical systems (MEMS) resonator, configured to oscillate in at least a first normal mode and a second normal mode. The sensor further includes: a coarse readout circuit configured to drive the first normal mode, measure a motion of the first normal mode, and derive from the measured motion a coarse measurement of the true acceleration or true external magnetic field; and a fine readout circuit configured to drive the second normal mode, measure a motion of the second normal mode, and derive from the measured motion and the coarse measurement a measurement of the difference between the true acceleration or true external magnetic field and the coarse measurement.

Abstract: A resonator includes an anchor, an outer stiffener ring on an outer perimeter of the resonator, and a plurality of curved springs between the anchor and the outer stiffener ring.

Abstract: An angular rate sensor. The sensor includes a Coriolis vibratory gyroscope (CVG) resonator, configured to oscillate in a first normal mode and in a second normal mode; a frequency reference configured to generate a reference signal; and a first phase control circuit. The first phase control circuit is configured to: measure a first phase difference between: a first phase target, and the difference between: a phase of an oscillation of the first normal mode and a phase of the reference signal. The first phase control circuit is further configured to apply a first phase correction signal to the CVG resonator, to reduce the first phase difference. A second phase control circuit is similarly configured to apply a second phase correction signal to the CVG resonator, to reduce a corresponding, second phase difference.

Abstract: A geopositioning system. The geopositioning system includes an accelerometer including three sensing axes, a gyroscope including three sensing axes, and a magnetometer including three sensing axes, and a processing circuit. The processing circuit is configured to calculate a location of the geopositioning system as a latitude, longitude, and altitude with respect to the Earth.

Abstract: A device preferably for use in an inertial navigation system the device having a single IC wafer; a plurality of sensors bonded to bond regions on said single IC wafer, at least one of said bond regions including an opening therein in gaseous communication with a pressure chamber associated with at least one of the plurality of said sensors; and a plurality of caps encapsulating said plurality of sensors, at least one of said plurality of caps forming at least a portion of said pressure chamber. A method of making the device is also disclosed.

Abstract: An angular sensor. The angular sensor includes a Coriolis vibratory gyroscope (CVG) resonator, configured to oscillate in a first pair of normal modes including a first normal mode and a second normal mode and a second pair of normal modes including a third normal mode and a fourth normal mode. The angular sensor further includes a coarse readout circuit configured to drive the first pair of modes, measure the motion of the first pair of modes, and derive from the measured motion of the first pair of modes a coarse measurement of an angular rate of the resonator. The angular sensor further includes and a fine readout circuit configured to derive a measurement of the difference between the true angular rate of the resonator and the coarse measurement.

Abstract: An angular sensor, comprising a Coriolis vibratory gyroscope (CVG) resonator, capable of oscillating along a first pair of normal n=1 modes comprising a first normal mode and a second normal mode; and a second pair of normal n=2 modes comprising a third normal mode and a fourth normal mode; the sensor further comprising one drive electrode and one sense electrode aligned along an anti-nodal axis of each mode; and a pair of bias tune electrodes aligned with an anti-nodal axis of each mode if no drive and sense electrode pair is aligned with said anti-nodal axis.

Abstract: A method of making a SiC resonator includes forming a layer of an oxide material on a relatively thick wafer of SiC; bonding the layer of oxide material on the relatively thick wafer of SiC to a handle wafer having at least an oxide exterior surface, the resulting bond being substantially free of voids; planarizing the relatively thick wafer of SiC to a desired thickness; forming top and bottom electrodes on the wafer of SiC wafer to define a SiC wafer resonator portion; and forming a trench around the top and bottom electrodes, the tench completely penetrating the planarized wafer of SiC around a majority of a distance surrounding said top and bottom electrodes, except for one or more tether regions of the planarized wafer of SiC which remain physically coupled a remaining portion the SiC wafer resonator portion which defines a frame formed of the planarized wafer of SiC surrounding the SiC wafer resonator portion.

Abstract: An instrument package for use during the drilling a wellbore. The instrument package includes a plurality of instruments such as accelerometers, gyroscopes, and magnetometers; a computer is configured to determine the current position of the plurality of instruments from a set of measurements produced by the plurality of instruments; and wherein the plurality of instruments are mechanically isolated from a drill head assembly by one or more multi-degree of freedom vibration isolators. The computer preferably has at least two modes different analytical modes of analyzing the set of measurements produced by the plurality of instruments, including a continuous mode and a survey mode, the continuous mode being operational during times that active drilling is occurring and the survey mode being operational during times that the active drilling is not occurring.

Abstract: A device preferably for use in an inertial navigation system the device having a single IC wafer; a plurality of sensors bonded to bond regions on said single IC wafer, at least one of said bond regions including an opening therein in gaseous communication with a pressure chamber associated with at least one of the plurality of said sensors; and a plurality of caps encapsulating said plurality of sensors, at least one of said plurality of caps forming at least a portion of said pressure chamber. A method of making the device is also disclosed.

Abstract: A phononic travelling wave gyroscope. The gyroscope includes a phononic waveguide including at least one loop. The phase change incurred by phonons propagating around the loop is compared to a reference phase, and utilized to form an estimate of the rotational rate of the gyroscope.

Abstract: A resonant structure comprising at least two coaxial rings, wherein adjacent coaxial rings have adjacent peripheries and are attached together by a plurality of connection structures regularly arranged along said adjacent peripheries; and wherein a first ring has a first ring portion with a first radial thickness and a second ring, portion, in a vicinity of a first connection structure, with a second radial thickness smaller than said first radial thickness.

Abstract: An angular sensor, comprising a Coriolis vibratory gyroscope (CVG) resonator, capable of oscillating along a first pair of normal n=1 modes comprising a first normal mode and a second normal mode; and a second pair of normal n=2 modes comprising a third normal mode and a fourth normal mode; the sensor further comprising one drive electrode and one sense electrode aligned along an anti-nodal axis of each mode; and a pair of bias tune electrodes aligned with an anti-nodal axis of each mode if no drive and sense electrode pair is aligned with said anti-nodal axis.

Abstract: A resonator includes an anchor, an outer stiffener ring on an outer perimeter of the resonator, and a plurality of curved springs between the anchor and the outer stiffener ring.

Abstract: A magnetometer system has a magnetometer, an interface circuit and an electronic demodulator, the interface circuit being coupled to sense electrodes disposed on the magnetometer and the demodulator being coupled to the interface circuit. Preferably, the magnetometer has a loop electrode which follows an outline of the shape of an active portion of the magnetometer and wherein the electronic demodulator has an output for driving the loop electrode of the magnetometer. Preferably, the magnetometer includes a quartz plate with flexural and thickness shear vibratory modes and wherein the flexural vibratory mode is driven, in use, into vibration by the electronic demodulator and wherein the thickness shear vibratory mode is driven, in use, into vibration by the interface circuit.

Abstract: A method for generating an output of a downhole inertial measurement unit (IMU) includes: generating a trajectory between a plurality of survey points of a planned well data as a function of time, wherein the planned well data includes a plurality of three-dimensional coordinates corresponding to the survey points of an underground planned well are used to generate a trajectory comprising a plurality of trajectory coordinates between the consecutive ones of the survey points; generating sensor data for each of the trajectory coordinates as a function of time based on the geodetic reference parameters, the generated sensor data comprising: generated accelerometer output; generated gyroscopic output; and generated magnetometer output; and outputting the generated accelerometer output; the generated gyroscopic output; and the generated magnetometer output as a function of time as a generated output of the downhole IMU.

Abstract: A method of fabricating a resonator includes providing a first quartz substrate, forming a metallic etch stop on a first surface of the first quartz substrate; attaching, using a temporary adhesive, the first surface of the first quartz substrate to a second quartz substrate, etching an opening for a via in a second surface of the first quartz substrate to the metallic etch stop, forming a metal electrode on the second surface of the first quartz substrate, the metal electrode penetrating the via in the first quartz substrate to make ohmic contact with the metallic etch stop, bonding the metal electrode formed on the second surface of the first quartz substrate to a pad formed on a host substrate; and dissolving the temporary adhesive to release the second quartz substrate from the first quartz substrate, wherein the first quartz substrate and the host substrate each comprise crystalline quartz.

Abstract: A resonator and/or a magnetometer has a resonating structure which is naturally resonant in at least one resonant mode, the resonating structure being significantly wider at a free end thereof than it is at a fixed end thereof, the resonating structure having at least one pair of sense electrodes disposed on opposing major surfaces of the resonating structure and having a conductive path formed as a loop, the loop being disposed near or at edges of the resonating structure so that the loop follows a path which is significantly wider at the free end of the resonating structure than it is at the fixed end of the resonating structure and wherein the at least one pair of sense electrodes are formed inwardly of the edges of the resonating structure and also inwardly of the path of the loop.

Abstract: A microelectromechanical (MEMS) sensor suite including a three axis accelerometer including an accelerometer sensor polyhedron having a series of faces, and a series of axial accelerometers on three faces of the series of faces of the accelerometer sensor polyhedron. The MEMS sensor suite also includes a three axis magnetometer including a magnetometer sensor polyhedron having a series of faces, and a series of axial magnetometers on three faces of the series of faces of the magnetometer sensor polyhedron.

Abstract: A magnetometer comprising a resonating structure which is naturally resonant in at least three resonant modes, a resonant frequency of the three modes being sufficiently separated to allow of detection of same, the resonating structure having two sense electrodes disposed on opposing major surfaces of the resonating structure and having a conductive path formed as a loop, the loop being disposed near or at edges of the resonating structure and the two sense electrodes being formed inwardly of the edges of the resonating structure and also inwardly of the loop.