Patents by Inventor Farrokh Ayazi

Farrokh Ayazi 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: 9726489
    Abstract: A single proof-mass, dual-axis gyroscope apparatus comprises a resonating body member and first and second electrodes each capacitively coupled to the resonating body member by a respective lateral capacitive air gap and a vertical capacitive air gap. The width of one of the lateral capacitive air gap of the first electrode is substantially smaller than the vertical capacitive air gap. The width of one of the vertical capacitive air gap of the second electrode is substantially smaller than the lateral capacitive air gap. The apparatus claimed can address the process variation such as vertical and lateral dimension variation by electrostatic tuning method.
    Type: Grant
    Filed: December 5, 2011
    Date of Patent: August 8, 2017
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Wang-kyung Sung, Mohammad Zaman
  • Publication number: 20170038211
    Abstract: Certain implementations of the disclosed technology may include systems and methods for high-frequency resonant gyroscopes. In an example implementation, a resonator gyroscope assembly is provided. The resonator gyroscope assembly can include a square resonator body suspended adjacent to a substrate, a ground electrode attached to a side of the resonator body, a piezoelectric layer attached to a side of the ground electrode, a drive electrode in electrical communication with the piezoelectric layer, and configured to stimulate one or more vibration modes of the square resonator body; and a sense electrode in electrical communication with the piezoelectric layer, and configured to receive an output from the square or disk resonator responsive to stimulation of the one or more vibration modes.
    Type: Application
    Filed: June 15, 2015
    Publication date: February 9, 2017
    Inventors: Farrokh Ayazi, Roozbeh Tabrizian, Mojtaba Hodjat-Shamami, Arashk Norouzpour-Shirazi
  • Publication number: 20160370183
    Abstract: A gyroscope having a resonant body utilizes a self-calibration mechanism that does not require physical rotation of the resonant body. Instead, interface circuitry applies a rotating electrostatic field to first and second drive electrodes simultaneously to excite both the drive and sense resonance modes of the gyroscope. When drive electrodes associated with both the drive and sense resonance modes of the gyroscope are excited by forces of equal amplitude but 90° phase difference, respectively, the phase shift in the gyroscope response, as measured by the current output of the sense electrodes for each resonance mode, is proportional to an equivalent gyroscope rotation rate.
    Type: Application
    Filed: May 20, 2016
    Publication date: December 22, 2016
    Inventors: Giorgio Casinovi, Farrokh Ayazi, Wang Kyung Sung, Milap Jayesh Dalal, Arashk Norouz Pour Shirazi
  • Publication number: 20160344368
    Abstract: Aspects of the present disclosure relate to microelectromechanical systems (MEMS) and methods for fabricating MEMS. In some embodiments, the system includes a resonator and a support stem. In some embodiments, the resonator is a hemisphere. The system can further include a front-side or back-side DC contact. The system can further include a levitation support, by which the resonator is virtually levitated from a substrate. In some embodiments, the resonator can be suitable for use in a microhemispherical resonator gyroscope Aspects of the present disclosure also relate to methods for fabricating axisymmetric resonators, including resonators for use in microhemispherical resonator gyroscopes.
    Type: Application
    Filed: May 22, 2015
    Publication date: November 24, 2016
    Inventors: Farrokh Ayazi, Peng Shao, Xin Gao, Vahid Tavassoli
  • Publication number: 20160327390
    Abstract: A resonant gyroscope apparatus has a decoupling mechanism implemented with spring-like flexure members to effectively isolate an axis-symmetric bulk-acoustic wave (BAW) vibratory gyroscope from its substrate, thereby minimizing the effect that external sources of error have on offset and scale-factor. The spring-like structure enables degeneracy of in-plane resonance modes of the annulus and aids in decoupling the in-plane and out-of-plane resonance modes of the resonant annulus, thereby enabling the mode-matched and/or near mode-matched operation of the structure as a vibratory gyroscope in the pitch, roll and yaw-modes.
    Type: Application
    Filed: January 13, 2015
    Publication date: November 10, 2016
    Inventors: Diego E. Serrano, Mohammad F. Zaman, Farrokh Ayazi, Amir Rahafrooz, Wang-Kyung Sung, Ijaz Jafri
  • Publication number: 20160258976
    Abstract: Accelerometers and associated techniques for detecting motion are described. For a resonant accelerometer, an externally-applied acceleration can cause a change in the electrical spring constant Ke of the electromechanical system. A resonant accelerometer can be driven to resonate in a bulk acoustic wave mode of vibration, which can have a high resonant frequency. Other accelerometers and associated techniques are disclosed.
    Type: Application
    Filed: March 7, 2016
    Publication date: September 8, 2016
    Inventor: Farrokh Ayazi
  • Patent number: 9347775
    Abstract: A gyroscope having a resonant body utilizes a self-calibration mechanism that does not require physical rotation of the resonant body. Instead, interface circuitry applies a rotating electrostatic field to first and second drive electrodes simultaneously to excite both the drive and sense resonance modes of the gyroscope. When drive electrodes associated with both the drive and sense resonance modes of the gyroscope are excited by forces of equal amplitude but 90° phase difference, respectively, the phase shift in the gyroscope response, as measured by the current output of the sense electrodes for each resonance mode, is proportional to an equivalent gyroscope rotation rate.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: May 24, 2016
    Assignee: Georgia Tech Research Corporation
    Inventors: Giorgio Casinovi, Farrokh Ayazi, Wang Kyung Sung, Milap Jayesh Dalal, Arashk Norouz Pour Shirazi
  • Publication number: 20160139176
    Abstract: A dual-mode actuation and sensing circuit actuates both modes of an axisymmetric gyroscope and senses both outputs thereof. The sum of the two outputs provides a self-sustaining closed-loop oscillation signal, while the difference of the two mode outputs is used for extracting differential rate information while rejecting the common-mode bias terms of the gyroscope to provide online bias calibration. The proposed system and method facilitates scale factor calibration of an axisymmetric gyroscope. Furthermore, the difference output of the dual-mode gyroscope can provide a mode-split indicator signal which can be used to automatically match the gyroscope modes.
    Type: Application
    Filed: November 16, 2015
    Publication date: May 19, 2016
    Inventors: Arashk Norouz Pour Shirazi, Farrokh Ayazi
  • Patent number: 9331264
    Abstract: A microelectromechanical resonator includes a resonator body having a semiconductor region therein that may be degenerately doped with boron. This high level of doping facilitates the formation of a eutectic alloy within the resonator body in response to resistive heating. The formation of a lattice-strained eutectic alloy within the resonator body supports reductions in the temperature coefficient of frequency (TCF) of the resonator over a relatively large temperature range.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: May 3, 2016
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Ashwin Samarao
  • Patent number: 9318998
    Abstract: An integrated circuit device includes a multi-port piezoelectric-on-semiconductor microelectromechanical resonator, which is configured to support independent and concurrent piezoelectric transduction of multiple resonance modes. The resonator includes a semiconductor resonator body (e.g., Si body) suspended opposite an underlying recess in a substrate. Opposite ends of the semiconductor resonator body are anchored to the substrate. The resonator body may be formed so that a plan layout view of a portion of the semiconductor resonator body is dumbbell-shaped to thereby support acoustic energy trapping of multiple high-Q resonance modes.
    Type: Grant
    Filed: August 30, 2013
    Date of Patent: April 19, 2016
    Assignee: Georgia Tech Research Corporation
    Inventors: Roozbeh Tabrizian, Farrokh Ayazi
  • Patent number: 9319020
    Abstract: A semiconductor resonator has a substrate with a thickness extending between a first end and a second end and a pn-junction along the thickness of the substrate forming a free charge carrier depletion region. In another embodiment, a semiconductor resonator has a substrate with a crystal lattice doped at degenerate levels such that the flow of free charge carriers can be minimized. A method of compensating a temperature coefficient of a semiconductor resonator by creating a pn-junction based free charge carrier depletion region within a thickness of a substrate of the resonator is also disclosed.
    Type: Grant
    Filed: October 19, 2011
    Date of Patent: April 19, 2016
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Ashwin Samarao
  • Publication number: 20160077126
    Abstract: A system and calibration method utilizes time averaging to suppress inherent capacitance mismatches or temperature variations in MEMS devices, such as a tri-axial accelerometer. An calibration interface circuit, operatively coupled the MEMS sensor, effectively cancels a range of non-ideal capacitive mismatches by employing pockets of calibration charges that are controlled by the duty-cycle of a clock.
    Type: Application
    Filed: September 15, 2015
    Publication date: March 17, 2016
    Inventors: Yaesuk Jeong, Farrokh Ayazi
  • Patent number: 9279824
    Abstract: Accelerometers and associated techniques for detecting motion are described. For a resonant accelerometer, an externally-applied acceleration can cause a change in the electrical spring constant Ke of the electromechanical system. A resonant accelerometer can be driven to resonate in a bulk acoustic wave mode of vibration, which can have a high resonant frequency. Other accelerometers and associated techniques are disclosed.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: March 8, 2016
    Assignee: GEORGIA TECH RESEARCH CORPORATION
    Inventor: Farrokh Ayazi
  • Patent number: 9154108
    Abstract: The present invention is directed towards a self-polarized capacitive micromechanical resonator apparatus and fabrication method. The apparatus includes a body member capable of retaining a polarization charge in the absence of a polarization voltage source. By creating potential wells or charge traps on the surface of the resonant body member through a nitrogen diffusing process, charges may be trapped in the charge traps. Unless perturbed externally, the charges remain trapped thus enabling a self-polarization technique without the need for any externally applied polarization voltage.
    Type: Grant
    Filed: July 6, 2011
    Date of Patent: October 6, 2015
    Inventors: Farrokh Ayazi, Ashwin Samarao
  • Patent number: 9003882
    Abstract: A high-Q, mode-matched, vibratory tuning fork based MEMS device, capable of sensing rotational and translational motion around three axes, and processes of fabrication are disclosed herein. In one embodiment, a MEMS device has first and second proof masses actuated along a first axis, and a third and fourth proof masses actuated along a second orthogonal axis. Each of the proof masses includes an inner mass mechanically coupled to an outer frame. A plurality of electrodes sense rotational or translational motion along the three orthogonal axes.
    Type: Grant
    Filed: November 3, 2011
    Date of Patent: April 14, 2015
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Divyanshu Agrawal
  • Patent number: 8763441
    Abstract: A gyroscope having a resonant body utilizes a self-calibration mechanism that does not require physical rotation of the resonant body. Instead, interface circuitry applies a rotating electrostatic field to first and second drive electrodes simultaneously to excite both the drive and sense resonance modes of the gyroscope. When drive electrodes associated with both the drive and sense resonance modes of the gyroscope are excited by forces of equal amplitude but 90° phase difference, respectively, the phase shift in the gyroscope response, as measured by the current output of the sense electrodes for each resonance mode, is proportional to an equivalent gyroscope rotation rate.
    Type: Grant
    Filed: April 11, 2012
    Date of Patent: July 1, 2014
    Assignee: Georgia Tech Research Corporation
    Inventors: Giorgio Casinovi, Farrokh Ayazi, Wang-Kyung Sung, Milap Jayesh Dalal, Arashk Norouz Pour Shirazi
  • Publication number: 20140157896
    Abstract: A gyroscope having a resonant body utilizes a self-calibration mechanism that does not require physical rotation of the resonant body. Instead, interface circuitry applies a rotating electrostatic field to first and second drive electrodes simultaneously to excite both the drive and sense resonance modes of the gyroscope. When drive electrodes associated with both the drive and sense resonance modes of the gyroscope are excited by forces of equal amplitude but 90° phase difference, respectively, the phase shift in the gyroscope response, as measured by the current output of the sense electrodes for each resonance mode, is proportional to an equivalent gyroscope rotation rate.
    Type: Application
    Filed: February 14, 2014
    Publication date: June 12, 2014
    Inventors: Giorgio Casinovi, Farrokh Ayazi, Wang Kyung Sung, Milap Jayesh Dalal, Arashk Norouz Pour Shirazi
  • Publication number: 20140102197
    Abstract: Accelerometers and associated techniques for detecting motion are described. For a resonant accelerometer, an externally-applied acceleration can cause a change in the electrical spring constant Ke of the electromechanical system. A resonant accelerometer can be driven to resonate in a bulk acoustic wave mode of vibration, which can have a high resonant frequency. Other accelerometers and associated techniques are disclosed.
    Type: Application
    Filed: September 9, 2013
    Publication date: April 17, 2014
    Inventor: Farrokh Ayazi
  • Patent number: 8680752
    Abstract: The present invention comprises systems, apparatuses, and methods for harvesting ambient mechanical energy at a lower frequency and transforming the harvested energy into electrical energy at a higher frequency. Transforming the energy from relatively lower input frequency energy to relatively higher output frequency energy can help realize greater efficiencies found at higher frequencies. Because the input plane of the ambient mechanical energy is not always predictable, some embodiments of the present invention comprise both in-plane and out-of-plane energy harvesters that produce an electrical output in multiple planes.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: March 25, 2014
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Logan Sorenson, Jenna Fu
  • Patent number: 8677821
    Abstract: Disclosed are methods and a sensor architecture that utilizes the residual quadrature error in a gyroscope to achieve and maintain perfect mode-matching, i.e., ˜0 Hz split between the drive and sense mode frequencies, and to electronically control sensor bandwidth. In a reduced-to-practice embodiment, a 6 mW, 3V CMOS ASIC and control algorithm are interfaced to a mode-matched MEMS tuning fork gyroscope to implement an angular rate sensor with bias drift as low as 0.15°/hr and angle random walk of 0.003°/?hr, which is the lowest recorded to date for a silicon MEMS gyroscope. The system bandwidth can be configured between 0.1 Hz and 1 kHz.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: March 25, 2014
    Assignee: Georgia Tech Research Coporation
    Inventors: Farrokh Ayazi, Ajit Sharma, Mohammad Faisal Zaman