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: 20220163413
    Abstract: An on-chip strain measurement device that uses precision frequency measurements to precisely extract sub-nm displacements, allowing residual strain measurements in a given structural film. Strain-induced gap changes to resonance frequencies use differential strategies to remove bias uncertainty, allowing measurement of sub-nm displacements. Gap-dependent electrical stiffness is used to shift resonance frequencies as structural elements stretch or shrink to relieve strain. An output based on differential frequencies between two proximal structures with unequal stress arm lengths removes uncertainty on the initial gap spacing. The ability to precisely measure the frequency of the high-Q structures allows lifetime stress correction of micromechanical circuits, such as oscillators and filters.
    Type: Application
    Filed: November 30, 2021
    Publication date: May 26, 2022
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Alper Ozgurluk
  • Publication number: 20210159868
    Abstract: System and methods for a hollow-disk radial-contour mode resonator structure. The hollow disk reduces the dynamic mass and stiffness of the structure. Since electromechanical coupling Cx/Co goes as the reciprocal of mass and stiffness, the hollow disk structure has a considerably stronger electromechanical coupling than a solid one at the same frequency, and thus raises Cx/Co without excessive gap-scaling. Several embodiments of hollow disk resonators are detailed, including asymmetric and symmetric disk configurations.
    Type: Application
    Filed: November 13, 2020
    Publication date: May 27, 2021
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Yafei Li, Alper Ozgurluk
  • Patent number: 10867757
    Abstract: A microelectromechanical resonant switch (“resoswitch”) converts received radio frequency (RF) energy into a clock output. The resoswitch first accepts incoming amplitude- or frequency-shift keyed clock-modulated RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the carrier clock waveform. The resulting output derives from the clock signal that originally modulated the RF carrier, resulting in a local clock that shares its originator's accuracy. A bare push-pull 1-kHz RF-powered mechanical clock generator driving an on-chip inverter gate capacitance of 5 fF can potentially operate with only 5 pW of battery power, 200,000 times lower than a typical real-time clock. Using an off-chip inverter with 17.5 pF of effective capacitance, a 1-kHz push-pull resonator would consume 17.5 nW.
    Type: Grant
    Filed: October 23, 2018
    Date of Patent: December 15, 2020
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Ruonan Liu, Jalal Naghsh Nilchi
  • Patent number: 10530337
    Abstract: Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.
    Type: Grant
    Filed: December 4, 2018
    Date of Patent: January 7, 2020
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Thura Lin Naing, Tristan O. Rocheleau
  • Publication number: 20190190497
    Abstract: Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.
    Type: Application
    Filed: December 4, 2018
    Publication date: June 20, 2019
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Thura Lin Naing, Tristan O. Rocheleau
  • Publication number: 20190157015
    Abstract: A microelectromechanical resonant switch (“resoswitch”) converts received radio frequency (RF) energy into a clock output. The resoswitch first accepts incoming amplitude- or frequency-shift keyed clock-modulated RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the carrier clock waveform. The resulting output derives from the clock signal that originally modulated the RF carrier, resulting in a local clock that shares its originator's accuracy. A bare push-pull 1-kHz RF-powered mechanical clock generator driving an on-chip inverter gate capacitance of 5 fF can potentially operate with only 5 pW of battery power, 200,000 times lower than a typical real-time clock. Using an off-chip inverter with 17.5 pF of effective capacitance, a 1-kHz push-pull resonator would consume 17.5 nW.
    Type: Application
    Filed: October 23, 2018
    Publication date: May 23, 2019
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Ruonan Liu, Jalal Naghsh Nilchi
  • Patent number: 10257002
    Abstract: A microelectromechanical resonant switch (“resoswitch”) converts received radio frequency (RF) energy into an output signal with zero quiescent power usage by using a resonant element with a passband input sensitivity of: <?60 dBm, <?68 dBm, and <?100 dBm. The resoswitch first accepts incoming amplitude- or frequency-shift keyed RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the modulating waveform. Mechanical gain may be used to amplify received signals, whose amplitudes may be binned, thereby preserving use of amplitude modulated (AM) signals. A second resoswitch may be used to control additional circuitry, whereby the first resoswitch detects a control signal output to the additional circuitry.
    Type: Grant
    Filed: June 19, 2017
    Date of Patent: April 9, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Wei-Chang Li, Ruonan Liu
  • Patent number: 10224875
    Abstract: A micro-electromechanical system (MEMS) frequency divider apparatus having one or more MEMS resonators on a substrate is presented. A first oscillator frequency, as an approximate multiple of the parametric oscillation frequency, is capacitively coupled from a very closely-spaced electrode (e.g., 40 nm) to a resonant structure of the first oscillator, thus inducing mechanical oscillation. This mechanical oscillation can be coupled through additional MEMS resonators on the substrate. The mechanical resonance is then converted, in at least one of the MEMS resonators, by capacitive coupling back to an electrical signal which is a division of the first oscillation frequency. Output may be generated as a single ended output, or in response to a differential signal between two output electrodes.
    Type: Grant
    Filed: June 1, 2016
    Date of Patent: March 5, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Tristan O. Rocheleau
  • Patent number: 10177742
    Abstract: Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.
    Type: Grant
    Filed: November 14, 2016
    Date of Patent: January 8, 2019
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Thura Lin Naing, Tristan O. Rocheleau
  • Patent number: 10050602
    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: Grant
    Filed: March 17, 2016
    Date of Patent: August 14, 2018
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Robert A. Schneider
  • Publication number: 20180145853
    Abstract: A microelectromechanical resonant switch (“resoswitch”) converts received radio frequency (RF) energy into an output signal with zero quiescent power usage by using a resonant element with a passband input sensitivity of: <?60 dBm, <?68 dBm, and <?100 dBm. The resoswitch first accepts incoming amplitude- or frequency-shift keyed RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the modulating waveform. Mechanical gain may be used to amplify received signals, whose amplitudes may be binned, thereby preserving use of amplitude modulated (AM) signals. A second resoswitch may be used to control additional circuitry, whereby the first resoswitch detects a control signal output to the additional circuitry.
    Type: Application
    Filed: June 19, 2017
    Publication date: May 24, 2018
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Wei-Chang Li, Ruonan Liu
  • Patent number: 9866172
    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: Grant
    Filed: March 28, 2014
    Date of Patent: January 9, 2018
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Lingqi Wu
  • Patent number: 9853679
    Abstract: A radio frequency (RF) MEMS resonator is embedded in an active positive feedback loop to form a tunable RF channel-selecting radio transceiver employing a super-regenerative reception scheme. This transceiver harnesses the exceptionally high Q (around 100,000) and voltage-controlled frequency tuning of a resonator structure to enable selection of any one of among twenty 1 kHz wide RF channels over an 80 kHz range, while rejecting adjacent channels and consuming <490 ?W. Such transceivers are well suited to wireless sensor node applications, where low-power and simplicity trump transmission rate. Electrical stiffness-based frequency tuning also allows this same device to operate as a frequency shift keyed (FSK) transmitter, making a complete transceiver in one simple device. Finally, the geometric flexibility of resonator structure design should permit a large range of usable RF frequencies, from the presently demonstrated 60.6-MHz VHF, all the way up to UHF.
    Type: Grant
    Filed: November 17, 2016
    Date of Patent: December 26, 2017
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Tristan O. Rocheleau, Thura Lin Naing
  • Publication number: 20170141810
    Abstract: A radio frequency (RF) MEMS resonator is embedded in an active positive feedback loop to form a tunable RF channel-selecting radio transceiver employing a super-regenerative reception scheme. This transceiver harnesses the exceptionally high Q (around 100,000) and voltage-controlled frequency tuning of a resonator structure to enable selection of any one of among twenty 1 kHz wide RF channels over an 80 kHz range, while rejecting adjacent channels and consuming <490 ?W. Such transceivers are well suited to wireless sensor node applications, where low-power and simplicity trump transmission rate. Electrical stiffness-based frequency tuning also allows this same device to operate as a frequency shift keyed (FSK) transmitter, making a complete transceiver in one simple device. Finally, the geometric flexibility of resonator structure design should permit a large range of usable RF frequencies, from the presently demonstrated 60.6-MHz VHF, all the way up to UHF.
    Type: Application
    Filed: November 17, 2016
    Publication date: May 18, 2017
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Tristan O. Rocheleau, Thura Lin Naing
  • Publication number: 20170126206
    Abstract: Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.
    Type: Application
    Filed: November 14, 2016
    Publication date: May 4, 2017
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Thura Lin Naing, Tristan O. Rocheleau
  • Publication number: 20170047893
    Abstract: A micro-electromechanical system (MEMS) frequency divider apparatus having one or more MEMS resonators on a substrate is presented. A first oscillator frequency, as an approximate multiple of the parametric oscillation frequency, is capacitively coupled from a very closely-spaced electrode (e.g., 40 nm) to a resonant structure of the first oscillator, thus inducing mechanical oscillation. This mechanical oscillation can be coupled through additional MEMS resonators on the substrate. The mechanical resonance is then converted, in at least one of the MEMS resonators, by capacitive coupling back to an electrical signal which is a division of the first oscillation frequency. Output may be generated as a single ended output, or in response to a differential signal between two output electrodes.
    Type: Application
    Filed: June 1, 2016
    Publication date: February 16, 2017
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Clark T.-C. Nguyen, Tristan O. Rocheleau
  • 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