University of California

Sitime Corporation

Bernhard Boser

David Horsley

Richard J Przybyla

Stefon Shelton

Hao-Yen Tang

Markus Lutz

Aaron Partridge

Yipeng Lu

Crist Y Lu

Burak Eminoglu

Ofer Rozen

Andre Guedes

Mitchell H Kline

Paul Merritt Hagelin

Peter A Krulevitch

Frederick F Becker

Julie K Hamilton

Xiao-Bo Wang

Adam B Eldredge

Octavian Florescu

Peter R C Gascoyne

Harold D Ackler

Stefan P Swierkowski

Christopher K Fuller

Igor Izyumin

Moritz Mattmann

Yu-Ching Yeh

A precision gyroscope which provides mode matching which is insensitive to rate input in response to continuously monitoring the split between the resonances of the drive and sense modes. A calibration signal, having at least one modulated term whose carrier is synchronous with the excitation in the drive resonator is utilized to modify the feedback signal in the sense resonator. The gyroscope thus does not suffer from corruption of, or from, the rate measurement; whereas the frequency of the calibration signal can be chosen independently of the bandwidth of the rate input.

Precision gyroscope mode-matching insensitive to rate input

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

Variable thickness diaphragm for a wideband robust piezoelectric micromachined ultrasonic transducer (PMUT)

A vibratory gyroscope system having a mechanical resonator (proof mass) and drive circuitry for maintaining oscillation in two axes at a small frequency split. Angular rate input is shifted to the frequency split and modulates both the frequency (FM) and the amplitude (AM) of the oscillations. Unlike other gyroscope modulation techniques which derive rate information from only the FM information and are subject to aliasing for rate signals with bandwidth exceeding the modulation frequency, the innovation uses both the FM and AM information. By exploiting their orthogonality, the image frequencies from the modulation cancel, thus removing the bandwidth limitation.

Bandwidth extension for continuous mode reversal gyroscope

MEMS ultrasound fingerprint ID systems are provided. Aspects of the systems include the capability of detecting both epidermis and dermis fingerprint patterns in three dimensions. Also provided are methods of making and using the systems, as well as devices that include the systems.

MUT fingerprint ID system

An ultrasonic imaging apparatus having a Micro-machined Ultrasonic Transducer (MUT), such as a Piezoelectric MUT (PMUT) or Capacitive MUT (CMUT), with a transmitting mode and a receiving mode for generating and sensing acoustic pressure in imaging applications. During transmission in a PMUT the inverse piezoelectric effect on the piezo layer causes transverse stress, which causes a bending moment in the PMUT structure leading to out-of-plane deflection. Different applied signs of voltage generates different signs of stress inside the piezo that in turn cause oscillating motion generating an acoustic pressure wave. During signal reception, incident pressure waves deflect the PMUT creating transverse stress, resulting in a charge determined through measuring voltage between electrodes. The apparatus is particularly well-suited for use in health care, such as measuring fat/muscle thickness, blood-flow, and blood pressure.

Miniature ultrasonic imaging system

An apparatus and method for frequency tuning/tracking between an electrical subsystem and a mechanical transducer subsystem is presented. An electromechanical transducer generates acoustic pulses as it is driven by a transmit signal from an electrical subsystem. As the transmit signal goes inactive, the settling behavior of the transducer is registered from which the difference in frequency between the resonance of the electromechanical transducer and the transmit signal frequency is determined and utilized for locking the electrical subsystem to the mechanical transducer subsystem by either tuning operating frequency of the electrical subsystem, or the mechanical transducer, to keep them matched (locked).

Frequency tuning and/or frequency tracking of a mechanical system with low sensitivity to electrical feedthrough

A frequency readout gyroscope is provided, having 2 or 3 axes, in which the frequency of the carrier associated with the oscillation of the proof mass changes while the amplitude stays constant. The invention departs from conventional gyroscopes which rely on measuring transducer sense axis displacement (amplitude modulation) to determine angular input rate. The invention utilizes what could be termed a form of frequency modulation, such as evaluating frequency phase difference between the axes of modulation. Examples include gyroscopes having either a quadrature or Lissajous FM mode of operation, in which angle random walk contribution from the electronics is reduced by approximately two orders of magnitude.

Frequency readout gyroscope

A vibratory gyroscope system is described which utilizes a mechanical resonator having a first mode of vibration and an associated first natural frequency, and a second mode of vibration having an associated second natural frequency. The angular rate of motion input couples energy between the first and second modes of vibration. The gyroscope has driver circuits, sensors and actuators for the first and second modes. The invention utilizes a bias error shifting method which provides for shifting the bias error away from DC to a higher frequency, where it can be removed by low pass filtering. As a result of the inventive method, gyroscope systems can be produced with significantly lower bias error.

Continuous mode reversal for rejecting drift in gyroscopes

An apparatus for determining location of a moveable object in relation to an input device includes an array of one or more piezoelectric micromachined ultrasonic transducer (pMUT) elements and a processor. The array is formed from a common substrate. The one or more pMUT elements include one or more transmitters and one or more receivers. The processor configured to determine a location of a moveable object in relation to an input device using sound waves that are emitted from the one or more transmitters, reflected from the moveable object, and received by the one or more receivers.

In-air ultrasonic rangefinding and angle estimation

An integrated magnetic field generation and detection platform is described that is capable of manipulating and detecting individual magnetic particles, such as spherical super-paramagnetic beads, and providing biosensing functionality. The platform is implemented in an integrated circuit, a portion of the surface of which is functionalized with one or more biochemical agents that binds tightly (i.e., specifically) with a target analyte. The magnetic beads are similarly functionalized with one or more biochemical agents that that bind specifically with the target analyte. When a sample is introduced, magnetic beads that specifically bind to the integrated circuit can be separated from non-specifically bound beads and detected.

Integrated magnetic field generation and detection platform

There are many inventions described and illustrated herein. In one aspect, the present inventions relate to a temperature measurement system comprising (1) a first microelectromechanical resonator to generate a first output signal having a frequency that varies with operating temperature, wherein the first microelectromechanical resonator includes a frequency function of temperature; (2) a second microelectromechanical resonator to generate a second output signal having a frequency that varies with operating temperature, wherein the second microelectromechanical resonator includes a frequency function of temperature; and (3) frequency division circuitry, coupled to the first and second microelectromechanical resonators, to determine data which is representative of the operating temperature of the first and/or second microelectromechanical resonator using (i) data which is representative of the frequency of the first output signal and (ii) data which is representative of the frequency of the second output signal. The frequency division circuitry may include circuitry to divide the frequency of the first output signal by the frequency of the second output signal (whether in digital or analog domain).

Growing community of inventors

Berkeley, CA, United States of America

Bernhard Boser