Abstract: A system and method for determining characteristics of a proximity sensor. According to a preferred embodiment, the admittance of a proximity sensor/cable assembly is measured at two frequencies. Assumptions about sensor characteristics and cable characteristics are made, and an admittance corresponding to the assumed characteristics is derived. The assumptions are adjusted to obtain a correspondence between the measured admittance and the derived admittance. When the assumptions have been updated a specified number of times or when a desired accuracy threshold has been met, the adjusted assumptions may be used to determine one or more sensor characteristics, such as the separation between the proximity sensor and the target object.

Abstract: Two sensor units are formed from magnetoresistive material. Elements of the first sensor unit have a total anisotropy field in a first direction. Elements of the second sensor unit have a total anisotropy field in a second direction. An integral coil sets a direction of magnetization in the elements of the first and second sensor units. An output of the first sensor unit is representative of magnetic field components perpendicular to the first direction and an output of the second sensor is representative of magnetic field components perpendicular to the second direction.

Abstract: Random pulse generators and generating systems using at least three oscillators. The output signals of at least two of the oscillators are combined to disturb the output signal of a final oscillator. For one configuration, combined output signals of at least two phase shift oscillators are used to modify the feedback signal of a final phase shift oscillator, thus disturbing the output signal of the final oscillator. For another configuration, the output signals of at least two phase shift oscillators are used to drive a subtractor whose output signal is combined with the output signal of a final phase shift oscillator to drive a subsequent subtractor, thus disturbing the output signal of the final oscillator.

Abstract: A high-voltage output buffer is implemented in a low-voltage semiconductor process. The buffer comprises a level translator circuit, the level translator operable to receive a signal varying between ground and a low voltage level, and to output a corresponding signal varying between a reference voltage level and a high voltage level. The reference voltage level is an intermediate voltage level between half of the low voltage level and the high voltage level. The buffer further comprises an output circuit operable to receive via an input the output of the level translator circuit, and to output a high voltage level when the input is a high voltage level or a zero voltage level when the input is at the reference voltage level.

Abstract: A multi-layer PZT comprises a plurality of stacked ceramic layers. The stack of ceramic layers includes a top ceramic layer on which negative and positive contacts for electrically coupling the PZT to external circuitry are formed. The stack of ceramic layers also includes at least one negatively poled ceramic layer having a negative conductive pattern formed thereon and at least one positively poled ceramic layer having a positive conductive pattern formed thereon. The PZT also includes a negative pattern interconnect for electrically connecting the negative contact and the negative conductive pattern and a positive pattern interconnect for electrically connecting the positive contact and the positive conductive pattern. The multi-layer PZT can be fabricated using a ceramic co-firing process.

Abstract: A ring laser gyro uses electrodes plated with a high corrosive resistant material to extend the life of the ring laser gyro. The material creates an environment that will prevent degradation of the ring laser gyro cathode and the mirrors which in turn will lengthen the life of a ring laser gyro.

Abstract: A semiconductor structure includes an upper and a lower layer of semiconductor material separated by a layer of insulation material. Resistors formed in the upper layer are connected into a Wheatstone bridge arrangement having an output. A first voltage provides power to the bridge. A second voltage connected to the lower layer of semiconductor material has a value selected to reduce the drift of the output following power up of the sensor.

Abstract: A circuit is protected from the application voltage from a high and a low voltage source that may power up at different times by supplying a circuit the applies an intermediate voltage whenever the high voltage has powered up when the low voltage has not until such time as the low voltage has powered up.

Abstract: A magnetometer package with a housing, a plurality of sensing elements, a board, and a sealing element. The housing has a first end, a second end, and a bore. The first end of the housing is adapted to receive the board and the sealing element. The second end of the housing is adapted to receive a plug. The plurality of sensing elements, the board, and the sealing element rest in the bore. The plurality of sensing elements are mounted on the board and are orientated so that their sensing axes sense magnetic fields in different directions.

Abstract: A method for fabricating a magneto-optic modulator, such as for use with a solid state ring resonator gyroscope. The method includes inducing a magnetic field at a substrate holder as a layer of magnetic material is being deposited on a substrate. The magnetic field helps to optimally orient the deposited magnetic material layer to improve the characteristics of the magneto-optic modulator. In addition to inducing a magnetic field, a low energy ion beam may be applied to optimize orientation. The method can be used to fabricate a magneto-optic modulator on a substrate containing a partially fabricated ring resonator without destroying previously fabricated components.

Abstract: Vibration induced errors in sensors are predicted based on a measurement of vibration power spectra. Accelerometer samples are used to estimate vibration power spectral densities. A calibration procedure using suitable vibration stimulus provides the ability to estimate sensitivity coefficients to be used to compensate for the vibration induced error. The vibration power spectrum estimates are combined with previously obtained calibration coefficients to generate real time vibration-induced error corrections. Vibration bias sensitivity coefficients are estimated in a controlled environment to ensure their accuracy to compensate the sensor in real-time applications using acceleration measurement devices such as accelerometers mounted to a rigid sensor assembly shared with the sensor to be compensated. Vibration bias estimates are then used to correct the outputs of the sensors(s) being compensated for vibration-induced error.

Abstract: A three-dimensional micro-coil situated in a planar substrate. Two wafers have metal strips formed in them, and the wafers are bonded together. The metal strips are connected in such a fashion to form a coil and are encompassed within the wafers. Also, metal sheets are formed on the facing surfaces of the wafers to result in a capacitor. The coil may be a single or multi-turn configuration. It also may have a toroidal design with a core volume created by etching a trench in one of the wafers before the metal strips for the coil are formed on the wafer. The capacitor can be interconnected with the coil to form a resonant circuit An external circuit for impedance measurement, among other things, and a processor may be connected to the micro-coil chip.

Abstract: A cryogenic inertial Micro-Electro-Mechanical System (MEMS) device is provided. The device may include a vibratory gyroscope operable to sense a rotational acceleration. The device may also include a pre-amplifier co-located in a close proximity to the vibratory gyroscope. The device may be operated at substantially low temperatures, such as cryogenic temperatures, to reduce electrical noise and improve stability of outputs of the system.

Abstract: A dither control system for a laser gyro having a dither motor for dithering the laser gyro through a desired angular displacement, known as the command angle, in response to a drive signal. In order to help avoid saturation of the laser gyro, the dither control system reduces the command angle by command angle reduction data when the average drive signal applied to the dither motor exceeds a maximum drive value until the command angle reduction data reaches zero. The command angle reduction value is calculated by integrating the difference between the average drive signal and the maximum drive value.

Abstract: A sensor for determining the on/off condition of a railroad car handbrake that utilizes a manual wheel which applies tension to a chain extending under the car to the brake setting system and the sensor utilizes a bias member which pushes against the side of the chain so that when the car brakes are not set, and the chain is loose, the bias member moves to distort the chain and such movement causes a sensor, such as a Hall effect device, to approach a magnetic member to produce a signal indicating that the brake is in a released condition.

Abstract: An output buffer is provided in the form of a voltage follower having a positive input that receives a reference voltage, a negative input and an output coupled together, and a control input that turns the voltage follower on and off. The output is coupled to one side of a load. The output buffer may have one or more additional voltage followers. For example, the output buffer may include three additional voltage followers with all voltage followers arranged as a low voltage differential signal (LVDS) buffer.

Abstract: A method is provided to form a LOCOS isolation in a CMOS SOI device. The SOI has a top silicon layer, a bottom silicon layer, and an insulation layer between the top and bottom silicon layers. An oxide layer is formed over the top silicon layer, and an LPCVD layer is deposited over the oxide layer. A photoresist is provided over the LPCVD layer that exposes a localized area of the LPCVD layer. The LPCVD layer and the oxide layer are etched away through the localized area to expose the top silicon layer. The silicon in the top silicon layer is etched so as to form a recess in the top silicon layer. The photoresist is removed and an isolation oxide is grown over the silicon in the recess so that the silicon in the recess is fully oxidized.

Abstract: A ring laser gyroscope (RLG) is configured with control circuits that are capable of automatic calibration. The RLG generates two laser beams in opposite directions around a closed loop path to determine angular rotation of the RLG. The laser beams propagate in a laser gain medium, and a laser intensity monitor circuit is operatively connected to the laser gain medium to monitor an intensity of the laser beams propagating in the laser gain medium. A dithering circuit is provided, including a dithering motor for mechanically oscillating the RLG at a controlled frequency and dither angle. A gain circuit is operatively connected to a detector array of the RLG to amplify a detector signal therefrom. According to the present invention, an automatically variable resistance is provided to calibrate the laser intensity monitor circuit of the RLG, to control the dither angle at which the dithering motor mechanically oscillates the RLG, and/or to calibrate the gain circuit of the RLG.

Abstract: An output buffer with built-in ESD protection is disclosed. The built-in ESD protection is preferably formed using transistors from the sea-of-transistors or sea-of-gates region of the integrated circuit, which may eliminate the need for dedicated ESD devices, and in particular, dedicated ESD devices that are pre-fabricated into the under-layers in and around the perimeter of the integrated circuit.

Abstract: A centered annular ring, or moat, is disposed on each of the six planar sides of a RLG block. The surface of each moat is slightly below the surrounding surface of each side of the block. Because each moat is recessed relative to the respective side surface, the moat surface is less likely to become scratched, and therefore allows for a better seal between the block and the components attached thereto.