Patents by Inventor Clark T. -C Nguyen

Clark T. -C Nguyen 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).

  • Publication number: 20160268999
    Abstract: A tunable Q resonator using a capacitive-piezoelectric transducer provides a flexible top electrode above an AlN resonator. The top electrode can be pulled electrostatically towards the resonator and substrate, forming a frictional contact with either the resonator or the combined resonator-electrode structure to the substrate, allowing for electrical tuning the Q of the resonator. With a sufficient electrostatic bias voltage Vb, the resonator may be completely turned OFF, allowing for an integrated switchable AlN resonator. Such switchable resonator may be integrated into a radio frequency (RF) front end as a digitally selectable band pass filter element, obviating the need for ancillary micromechanical switches in the signal path. The device has been demonstrated with a Q approaching 9,000, together with ON/OFF switchability and electromechanical coupling up to 0.63%.
    Type: Application
    Filed: March 17, 2016
    Publication date: September 15, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Robert A. Schneider
  • Patent number: 9431201
    Abstract: A circuit of N micromechanical resonant switches (resoswitches) is presented, which mimics a Dickson charge pump to amplify an input voltage to an output voltage of N plus 1 times the input voltage, while avoiding the diode voltage drop and breakdown voltage limitations of CMOS-based conventional charge pumps. Important aspects of successful charge pumping are: 1) the long cycle lifetime of resonant micromechanical switches, which has been shown to operate 173.9×1012 cycles, is orders of magnitude higher than non-resonant switches; 2) the use of gated-sinusoid drive excitation to allow a charging period independent of resoswitch resonance frequency; and 3) the use of resonance operation to lower required drive and DC-bias voltages to below the supply voltage. This mechanical charge pump obviates the need for custom high voltage CMOS for applications where large voltages are needed such as MEMS-based timing references, thereby allowing the use of virtually any CMOS process.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: August 30, 2016
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Yang Lin
  • Publication number: 20160164458
    Abstract: A micromechanical resonator having one or more anchoring stems which are hollow to increase resonator Q factor. By way of example a micromechanical disk resonator embodiment is shown utilizing a resonant micromechanical disk anchored by a stem between at least one electrode used for input and output. To increase resonator Q, a hollow stem is utilized in which an outer thickness of stem material surrounds a hollow area interior of the stem, or that is fabricated with a plurality of vias and/or fabricated substructures containing hollow spaces in the stem material. Measurements have confirmed that Q values can be increased using the hollow core stems by a factor of 2.9 times in certain implementations and operating modes.
    Type: Application
    Filed: March 28, 2014
    Publication date: June 9, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Lingqi Wu
  • Publication number: 20160155595
    Abstract: A circuit of N micromechanical resonant switches (resoswitches) is presented, which mimics a Dickson charge pump to amplify an input voltage to an output voltage of N plus 1 times the input voltage, while avoiding the diode voltage drop and breakdown voltage limitations of CMOS-based conventional charge pumps. Important aspects of successful charge pumping are: 1) the long cycle lifetime of resonant micromechanical switches, which has been shown to operate 173.9×1012 cycles, is orders of magnitude higher than non-resonant switches; 2) the use of gated-sinusoid drive excitation to allow a charging period independent of resoswitch resonance frequency; and 3) the use of resonance operation to lower required drive and DC-bias voltages to below the supply voltage. This mechanical charge pump obviates the need for custom high voltage CMOS for applications where large voltages are needed such as MEMS-based timing references, thereby allowing the use of virtually any CMOS process.
    Type: Application
    Filed: December 4, 2015
    Publication date: June 2, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Yang Lin
  • Patent number: 7911296
    Abstract: A resonator system such as a microresonator system and a method of making same are provided. In at least one embodiment, a mechanical circuit-based approach for boosting the Q of a vibrating micromechanical resonator is disclosed. A low Q resonator is embedded into a mechanically-coupled array of much higher Q resonators to raise the functional Q of the composite resonator by a factor approximately equal to the number of resonators in the array. The availability of such a circuit-based Q-enhancement technique has far reaching implications, especially considering the possibility of raising the functional Q of a piezoelectric resonator by merely mechanically coupling it to an array of much higher Q capacitively-transduced ones to simultaneously obtain the most attractive characteristics of both technologies: low impedance from the piezo-device and high-Q from the capacitive ones. Furthermore, the manufacturing repeatability of such micromechanical resonator-based products is enhanced.
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: March 22, 2011
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T. C. Nguyen, Yu-Wei Lin
  • Patent number: 7551043
    Abstract: Micromechanical structures having at least one lateral capacitive transducer gap filled with a dielectric and method of making same are provided. VHF and UHF MEMS-based vibrating micromechanical resonators filled with new solid dielectric capacitive transducer gaps to replace previously used air gaps have been demonstrated at 160 MHz, with Q's˜20,200 on par with those of air-gap resonators, and motional resistances (Rx's) more than 8× smaller at similar frequencies and bias conditions. This degree of motional resistance reduction comes about via not only the higher dielectric constant provided by a solid-filled electrode-to-resonator gap, but also by the ability to achieve smaller solid gaps than air gaps. These advantages with the right dielectric material may now allow capacitively-transduced resonators to match to the 50-377? impedances expected by off-chip components (e.g., antennas) in many wireless applications without the need for high voltages.
    Type: Grant
    Filed: August 28, 2006
    Date of Patent: June 23, 2009
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Yu-Wei Lin, Sheng-Shian Li, Yuan Xie
  • Patent number: 7295088
    Abstract: High-Q micromechanical resonator devices and filters utilizing same are provided. The devices and filters include a vibrating polysilicon micromechanical “hollow-disk” ring resonators obtained by removing quadrants of material from solid disk resonators, but purposely leaving intact beams or spokes of material with quarter-wavelength dimensions to non-intrusively support the resonators. The use of notched support attachments closer to actual extensional ring nodal points further raises the Q. Vibrating micromechanical hollow-disk ring filters including mechanically coupled resonators with resonator Q's greater than 10,000 achieve filter Q's on the order of thousands via a low-velocity coupling scheme. A longitudinally mechanical spring is utilized to attach the notched-type, low-velocity coupling locations of the resonators in order to achieve a extremely narrow passband.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: November 13, 2007
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Sheng-Shian Li
  • Patent number: 7119636
    Abstract: A micromechanical resonate device having an extensional wine-glass mode shape is described herein. Different embodiments of the device may employ vibrating polysilicon micromechanical ring resonators, utilizing a unique extensional wine-glass mode shape to achieve lower impedance than previous UHF resonators at frequencies as high as 1.2-GHz with a Q of 3,700, and 1.47-GHz (highest to date for polysilicon micromechanical resonators) with a Q of 2,300. The 1.2-GHz resonator exhibits a measured motional resistance of 560 k? with a dc-bias voltage of 20V, which is 6× lower than measured on radial contour mode disk counterparts at the same frequency, and which can be driven down as low as 2 k? when a dc-bias voltage of 100V and electrode-to-resonator gap spacing of 460 ? are used.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: October 10, 2006
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T. -C. Nguyen, Yuan Xie
  • Patent number: 6985051
    Abstract: A micromechanical resonator device and a method of making the micromechanical resonator device, as well as other extensional mode devices are provided wherein anchor losses are minimized by anchoring at one or more side nodal points of the resonator device. Lower damping forces are experienced by the resonator device when operated in air.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: January 10, 2006
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Mohamed A. Abdelmoneum
  • Patent number: 6958566
    Abstract: A mechanical resonator device which has a phenomena-dependent electrical stiffness is provided. The phenomena may be temperature or acceleration, for example. The device includes a substrate and a resonator supported above the substrate by supports. The device further includes an electrode supported above the substrate adjacent the resonator by supports to obtain an electrode-to-resonator gap wherein electrical stiffness generated across the gap is phenomena-dependent to take instability of resonant frequency of the device caused by the phenomena into consideration.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: October 25, 2005
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Wan-Thai Hsu
  • Patent number: 6954301
    Abstract: A low-voltage electromechanical device including a tiltable microplatform, method of tilting same and array of such devices are provided. The tiltable or steerable microplatform utilizes a bent-beam actuator to achieve large tilting angles with low actuation voltages. Thin beams of the actuator are bent in such a way as to cause the microplatform to pivot around a dimple support that generates a torsional force leading to angular motion in suspension beams attached perpendicular to the thin beams and, in turn, leading to angular or tilting motion in the suspended microplatform. Some of the key features include (1) the low-voltage bent-beam actuator; (2) a dimple-supported microplatform with a hole underneath in the substrate to allow light to pass through and to allow unhindered tilting of the microplatform; and (3) a method for constructing a microprism on the tiltable transparent microplatform for color dispersion purposes in an adaptive vision system.
    Type: Grant
    Filed: April 29, 2003
    Date of Patent: October 11, 2005
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Yuan Xie
  • Patent number: 6917138
    Abstract: Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. A method and subsystem are provided for processing RF signals utilizing a plurality of vibrating micromechanical devices typically in the form of an IF mixer-filter and an RF channel selector or an image-reject RF filter. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Also, such methods and circuits can eliminate the need for a low noise amplifier in a receiver or transceiver subsystem. Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.
    Type: Grant
    Filed: July 24, 2003
    Date of Patent: July 12, 2005
    Assignee: The Regents of the University of Michigan
    Inventor: Clark T. -C. Nguyen
  • Patent number: 6856217
    Abstract: A micromechanical resonator device and a micromechanical device utilizing same are disclosed based upon a radially or laterally vibrating disk structure and capable of vibrating at frequencies well past the GHz range. The center of the disk is a nodal point, so when the disk resonator is supported at its center, anchor dissipation to the substrate is minimized, allowing this design to retain high-Q at high frequency. In addition, this design retains high stiffness at high frequencies and so maximizes dynamic range. Furthermore, the sidewall surface area of this disk resonator is often larger than that attainable in previous flexural-mode resonator designs, allowing this disk design to achieve a smaller series motional resistance than its counterparts when using capacitive (or electrostatic) transduction at a given frequency. Capacitive detection is not required in this design, and piezoelectric, magnetostrictive, etc. detection are also possible.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: February 15, 2005
    Assignee: The Regents of the University of Michigan
    Inventors: John R. Clark, Clark T.-C. Nguyen
  • Patent number: 6846691
    Abstract: A method and resulting formed device are disclosed wherein the method combines polysilicon surface-micromachining with metal electroplating technology to achieve a capacitively-driven, lateral micromechanical resonator with submicron electrode-to-resonator capacitor gaps. Briefly, surface-micromachining is used to achieve the structural material for a resonator, while conformal metal-plating is used to implement capacitive transducer electrodes. This technology makes possible a variety of new resonator configurations, including disk resonators and lateral clamped-clamped and free-free flexural resonators, all with significant frequency and Q advantages over vertical resonators. In addition, this technology introduces metal electrodes, which greatly reduces the series resistance in electrode interconnects, thus, minimizing Q-loading effects while increasing the power handling ability of micromechanical resonators.
    Type: Grant
    Filed: July 24, 2003
    Date of Patent: January 25, 2005
    Assignee: The Regents of the University of Michigan
    Inventors: Wan-Thai Hsu, John R. Clark, Clark T. C. Nguyen
  • Publication number: 20040207492
    Abstract: A micromechanical resonator device and a method of making the micromechanical resonator device, as well as other extensional mode devices are provided wherein anchor losses are minimized by anchoring at one or more side nodal points of the resonator device. Lower damping forces are experienced by the resonator device when operated in air.
    Type: Application
    Filed: December 16, 2003
    Publication date: October 21, 2004
    Inventors: Clark T.-C. Nguyen, Mohamed A. Abdelmoneum
  • Publication number: 20040109222
    Abstract: A low-voltage electromechanical device including a tiltable microplatform, method of tilting same and array of such devices are provided. The tiltable or steerable microplatform utilizes a bent-beam actuator to achieve large tilting angles with low actuation voltages. Thin beams of the actuator are bent in such a way as to cause the microplatform to pivot around a dimple support that generates a torsional force leading to angular motion in suspension beams attached perpendicular to the thin beams and, in turn, leading to angular or tilting motion in the suspended microplatform. Some of the key features include (1) the low-voltage bent-beam actuator; (2) a dimple-supported microplatform with a hole underneath in the substrate to allow light to pass through and to allow unhindered tilting of the microplatform; and (3) a method for constructing a microprism on the tiltable transparent microplatform for color dispersion purposes in an adaptive vision system.
    Type: Application
    Filed: April 29, 2003
    Publication date: June 10, 2004
    Inventors: Clark T.-C. Nguyen, Yuan Xie
  • Patent number: 6742389
    Abstract: A method and system for measuring angular speed of an object uses a micromechanical filter apparatus and allows Q-multiplication in both drive and sense modes. The invention takes advantage of the constant amplitude region of a filter spectrum within a passband of the filter apparatus to sense with a constant scaling factor that is independent of frequency variations with the passband. Thus, the system has much less sensitivity to drive mode resonance frequency shifts due to temperature variations, fabrication non-idealities and aging. The system senses angular rate or speed at resonance, which results in a great improvement over conventional gyroscopes operated off-resonance.
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: June 1, 2004
    Assignee: The Regents of the University of Michigan
    Inventors: Clark T.-C. Nguyen, Mustafa U. Demirci
  • Patent number: 6739190
    Abstract: A micromechanical resonator device is disclosed that utilizes competition between the thermal dependencies of geometrically tailored stresses and Young's modulus to (1) reduce the temperature coefficient (TCf) of the resonance frequencies of the micromechanical resonator device without any additional power consumption; and (2) introduce a zero TCf temperature at which subsequent oven-controlled resonators may be biased. A key feature in this resonator design involves the strategic sizing of the geometries of the resonator and its support structure to harness thermal expansion temperature coefficients that oppose and cancel those of Young's modulus variation. This transforms the original monotonically decreasing resonance frequency versus temperature curve to an S-shaped curve (or a linear one with a much smaller slope), with a smaller overall frequency excursion over a given temperature range, and with points at which the resonance frequency TCf is zero.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: May 25, 2004
    Assignee: The Regents of the University of Michigan
    Inventors: Wan-Thai Hsu, Clark T. C. Nguyen
  • Publication number: 20040095210
    Abstract: Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. A method and subsystem are provided for processing RF signals utilizing a plurality of vibrating micromechanical devices typically in the form of an IF mixer-filter and an RF channel selector or an image-reject RF filter. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Also, such methods and circuits can eliminate the need for a low noise amplifier in a receiver or transceiver subsystem. Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.
    Type: Application
    Filed: July 24, 2003
    Publication date: May 20, 2004
    Applicant: The Regents of the University of Michigan
    Inventor: Clark T.-C. Nguyen
  • Patent number: 6713938
    Abstract: Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. Apparatus is provided for filtering signals utilizing vibrating micromechanical resonators. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: March 30, 2004
    Assignee: The Regents of the University of Michigan
    Inventor: Clark T.-C. Nguyen