Patents by Inventor David T. Chang

David T. Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9991863
    Abstract: A piezoelectric quartz shear-mode resonator includes plasma etched quartz tethers, each including a mount. The tethers are for mounting the resonator to a semiconductor substrate for the purpose of isolating the thermally-induced stress from the mounts from the active resonating region, wherein the quartz tethers have rounded corners.
    Type: Grant
    Filed: April 7, 2015
    Date of Patent: June 5, 2018
    Assignee: HRL Laboratories, LLC
    Inventors: Randall L. Kubena, Deborah J. Kirby, David T. Chang
  • Patent number: 9985198
    Abstract: High-yield fabrication methods are provided for making quartz resonators having thicknesses ranging from one micrometer to several hundred micrometers and thus covering the frequency range from HF to UHF. Plasma dry etching is used to form arbitrary resonator geometries. The quartz resonator structure and the through-quartz vias are formed concurrently. The method includes bonding a quartz device wafer to a quartz handle wafer with a temporary adhesive. Mesa structures formed by plasma dry etching enable the resonators to achieve high-Q operation with energy trapping/mode confinement. A thermo-compression bond integrates the quartz resonators to a host wafer (e.g., an oscillator ASIC) to form oscillators. Silicon cap wafers are bonded over the resonators to the ASIC to provide wafer scale hermetic encapsulation of the quartz oscillators.
    Type: Grant
    Filed: May 23, 2014
    Date of Patent: May 29, 2018
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Frederic P. Stratton, Hung Nguyen, Randall L. Kubena
  • Patent number: 9977097
    Abstract: A magnetometer has a resonating structure which is naturally resonant in at least first and second resonant modes, a resonant frequency of the second mode being at least an order of magnitude greater than a resonant frequency of the first mode, 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 said loop.
    Type: Grant
    Filed: February 20, 2015
    Date of Patent: May 22, 2018
    Assignee: HRL Laboratories, LLC
    Inventors: Hung Nguyen, Logan D. Sorenson, David T. Chang, Raviv Perahia, Deborah J. Kirby, Richard J. Joyce
  • Patent number: 9879997
    Abstract: A resonator assembly includes a semiconductor substrate; a resonator gyroscope, the resonator gyroscope including a first resonator formed in a layer of a first material; and an oscillator on the semiconductor substrate, the oscillator including a second resonator formed of a second material. The second resonator is disposed in a cavity, the cavity comprising a first recess in the layer of a first material with the edges of the first recess being attached to the substrate, or the cavity comprising a second recess in the substrate and the edges of the second recess being attached to the layer of a first material.
    Type: Grant
    Filed: November 18, 2014
    Date of Patent: January 30, 2018
    Assignee: HRL Laboratories, LLC
    Inventors: Randall L. Kubena, Yook-Kong Yong, Deborah J. Kirby, David T. Chang
  • Publication number: 20170292840
    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.
    Type: Application
    Filed: December 21, 2016
    Publication date: October 12, 2017
    Inventors: Logan D. Sorenson, Hung Nguyen, Raviv Perahia, Deborah J. Kirby, Richard J. Joyce, David T. Chang
  • Patent number: 9599470
    Abstract: A gyroscope includes a cylindrical shell having a first end and a second end, a base on the second end of the shell, a substrate, an anchor coupling the base to the substrate, and electrodes for driving and sensing mechanically separated from the cylindrical shell.
    Type: Grant
    Filed: September 11, 2013
    Date of Patent: March 21, 2017
    Assignee: HRL Laboratories, LLC
    Inventors: Deborah J. Kirby, Raviv Perahia, Hung Nguyen, David T. Chang, Tracy J. Boden
  • Patent number: 9404748
    Abstract: An apparatus for driving and sensing motion in a gyroscope including a dielectric mass, an anchor, a spring coupled between the anchor and the dielectric mass, a substrate adjacent the dielectric mass, an insulator layer on the substrate, and a first electrode and a second electrode on the insulator layer. When an alternating current voltage is applied between the first and second electrodes, an electric field gradient is generated in the dielectric mass and causes the dielectric mass to move relative to the anchor. When the dielectric mass has motion relative to the anchor and a voltage is applied between the first and second electrodes, the movement of the dielectric mass generates a current at the first and second electrodes proportional to the motion.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: August 2, 2016
    Assignee: HRL Laboratories, LLC
    Inventors: Raviv Perahia, Hung Nguyen, Deborah J. Kirby, Srikanth S. Iyer, David T. Chang
  • Patent number: 9250074
    Abstract: A resonator assembly comprising a semiconductor substrate, a resonator gyroscope, the resonator gyroscope including a first resonator formed in a layer of a first material, and an oscillator on the semiconductor substrate, the oscillator including a second resonator formed of a second material, wherein the second resonator is attached in a cavity; the cavity comprising a first recess in said layer of a first material and the edges of the first recess being attached to the substrate, or the cavity comprising a second recess in said substrate and the edges of the second recess being attached to said layer of a first material.
    Type: Grant
    Filed: April 10, 2014
    Date of Patent: February 2, 2016
    Assignee: HRL Laboratories, LLC
    Inventors: Randall L. Kubena, David T. Chang
  • Patent number: 9061886
    Abstract: A resonator includes a base substrate with anchor pads, and a quartz resonator device including a resonant microbridge with an electrode, a first flexure beam connected to an end of the microbridge, a second flexure beam connected to a second end of the microbridge, a first and second spring connected between the first flexure beam and first and second anchor mounts, respectively, a third and fourth spring connected between the second flexure beam and third and fourth anchor mounts, respectively, the anchor mounts connected to anchor pads on the base substrate. A single crystal quartz includes the microbridge, the flexure beams, the springs, and the anchor mounts. The flexure beams and the springs prevent buildup of stress in the microbridge.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: June 23, 2015
    Assignee: HRL Laboratories, LLC
    Inventors: Hung Nguyen, Deborah J. Kirby, David T. Chang
  • Patent number: 9046541
    Abstract: A method for producing a disk resonator gyroscope includes providing a base substrate and a handle wafer with a release hole, bonding a release wafer to the handle wafer, bonding a resonator wafer to the release wafer, etching the resonator wafer to form a disk resonator with a central pillar, and sense and drive electrodes, selectively applying a conductive film onto the disk resonator on a side of the disk resonator opposite the release wafer, on the outer edge of the disk resonator, and on the surfaces of the sense and drive electrodes facing the outer edge of the disk resonator, bonding the sense and drive electrodes and the central pillar of the disk resonator to the base substrate, and releasing the handle wafer by introducing a dry release agent into the release hole to undercut the release wafer.
    Type: Grant
    Filed: October 9, 2012
    Date of Patent: June 2, 2015
    Assignees: HRL Laboratories, LLC, The Boeing Company
    Inventors: Randall L. Kubena, David T. Chang, Robert L. Larson
  • Publication number: 20150000401
    Abstract: An apparatus for driving and sensing motion in a gyroscope including a dielectric mass, an anchor, a spring coupled between the anchor and the dielectric mass, a substrate adjacent the dielectric mass, an insulator layer on the substrate, and a first electrode and a second electrode on the insulator layer. When an alternating current voltage is applied between the first and second electrodes, an electric field gradient is generated in the dielectric mass and causes the dielectric mass to move relative to the anchor. When the dielectric mass has motion relative to the anchor and a voltage is applied between the first and second electrodes, the movement of the dielectric mass generates a current at the first and second electrodes proportional to the motion.
    Type: Application
    Filed: June 28, 2013
    Publication date: January 1, 2015
    Inventors: Raviv Perahia, Hung Nguyen, Deborah J. Kirby, Srikanth S. Iyer, David T. Chang
  • Patent number: 8912711
    Abstract: In an embodiment, a thermal stress resistant resonator is disclosed. The thermal stress resistant resonator may include or comprise a piezoelectric member having one or more non-linear piezoelectric support members extending there from.
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: December 16, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Tsung-Yuan Hsu
  • Patent number: 8782876
    Abstract: A process for fabricating an integrated Micro-Electro-Mechanical Systems (MEMS) filter includes bonding an insulating substrate having a first end and a second end to a base substrate, the second end of the insulating substrate cantilevered over and separated from the base substrate by a gap, forming a resonator element on the second end of the insulating substrate, forming an inductive element comprising a coil, wherein the coil is formed on the insulating substrate, and forming a capacitive element on the first side of the insulating substrate, the capacitive element comprised of two conductive plates, wherein one of the two conductive plates is formed on the insulating substrate.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: July 22, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: Randall L. Kubena, David T. Chang
  • Patent number: 8778800
    Abstract: This invention provides a micro-supercapacitor with high energy density and high power density. In some variations, carbon nanostructures, such as carbon nanotubes, coated with a metal oxide, such as ruthenium oxide, are grown in a supercapacitor cavity that contains no separator. A lid is bonded to the cavity using a bonding process to form a hermetic seal. These micro-supercapacitors may be fabricated from silicon-on-insulator wafers according to the disclosed methods. An exemplary micro-supercapacitor is cubic with a length of about 50-100 ?m. The absence of a separator translates to higher energy storage volume and less wasted space within the supercapacitor cell. The energy density of the micro-supercapacitor may exceed 150 J/cm3 and the peak output power density may be in the range of about 2-20 W/cm3, in various embodiments.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: July 15, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Pamela R. Patterson, Ping Liu
  • Patent number: 8769802
    Abstract: A method for manufacturing a resonator is presented in the present application. The method includes providing a handle substrate, providing a host substrate, providing a quartz substrate comprising a first surface opposite a second surface, applying interposer film to the first surface of the quartz substrate, bonding the quartz substrate to the handle substrate wherein the interposer film is disposed between the quartz substrate and the handle substrate, thinning the second surface of the quartz substrate, removing a portion of the bonded quartz substrate to expose a portion of the interposer film, bonding the quartz substrate to the host substrate, and removing the handle substrate and the interposer film, thereby releasing the quartz substrate.
    Type: Grant
    Filed: July 6, 2010
    Date of Patent: July 8, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Randall L. Kubena, Pamela R. Patterson
  • Patent number: 8766745
    Abstract: A disk resonator gyroscope includes a quartz base, a quartz resonator disk having a central pillar connected to the base, the quartz resonator disk having a surface facing the base and having plurality of circumferential slots in the surface of the quartz resonator disk around the central pillar, and an electrode comprised of quartz and connected to the base outside of an outer edge of the resonator disk.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: July 1, 2014
    Assignees: HRL Laboratories, LLC, The Boeing Company
    Inventors: Randall L. Kubena, David T. Chang, Robert L. Larson
  • Patent number: 8765615
    Abstract: A quart resonator for use in lower frequency applications (typically lower than the higher end of the UHF spectrum) where relatively thick quartz members, having a thickness greater than ten microns, are called for.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: July 1, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Frederic P. Stratton, Hung Nguyen, Randall L. Kubena
  • Patent number: 8698201
    Abstract: A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate of a first dielectric, forming first sidewalls of a second dielectric on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a dielectric layer over the mesa, planarizing the dielectric layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the dielectric layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.
    Type: Grant
    Filed: August 15, 2013
    Date of Patent: April 15, 2014
    Assignee: HRL Laboratories, LLC
    Inventors: Dean C. Regan, Keisuke Shinohara, Andrea Corrion, Ivan Milosavljevic, Miroslav Micovic, Peter J. Willadsen, Colleen M. Butler, Hector L. Bracamontes, Bruce T. Holden, David T. Chang
  • Patent number: 8558281
    Abstract: A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate including silicon, forming first sidewalls of a first material on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a material layer over the mesa, planarizing the material layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the material layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: October 15, 2013
    Assignee: HRL Laboratories, LLC
    Inventors: Dean C. Regan, Keisuke Shinohara, Andrea Corrion, Ivan Milosavljevic, Miroslav Micovic, Peter J. Willadsen, Colleen M. Butler, Hector L. Bracamontes, Bruce T. Holden, David T. Chang
  • Patent number: 8503161
    Abstract: This invention provides a micro-supercapacitor with high energy density and high power density. In some variations, carbon nanostructures, such as carbon nanotubes, coated with a metal oxide, such as ruthenium oxide, are grown in a supercapacitor cavity that contains no separator. A lid is bonded to the cavity using a bonding process to form a hermetic seal. These micro-supercapacitors may be fabricated from silicon-on-insulator wafers according to the disclosed methods. An exemplary micro-supercapacitor is cubic with a length of about 50-100 ?m. The absence of a separator translates to higher energy storage volume and less wasted space within the supercapacitor cell. The energy density of the micro-supercapacitor may exceed 150 J/cm3 and the peak output power density may be in the range of about 2-20 W/cm3, in various embodiments.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: August 6, 2013
    Assignee: HRL Laboratories, LLC
    Inventors: David T. Chang, Pamela R. Patterson, Ping Liu