Patents by Inventor Mina Raieszadeh

Mina Raieszadeh 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: 9742373
    Abstract: A method of making a temperature-compensated resonator is presented. The method comprises the steps of: (a) providing a substrate including a device layer; (b) replacing material from the device layer with material having an opposite temperature coefficient of elasticity (TCE) along a pre-determined region of high strain energy density for the resonator; (c) depositing a capping layer over the replacement material; and (d) etch-releasing the resonator from the substrate. The resonator may be a part of a micro electromechanical system (MEMS).
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: August 22, 2017
    Assignee: The Regents of the University of Michigan
    Inventors: Mina Raieszadeh, Zhengzheng Wu, Vikram Atul Thakar, Adam Peczalski
  • Patent number: 9419213
    Abstract: An RF switch is provided with a direct heating method. The RF switch is comprised of two RF electrodes disposed on opposing sides of a phase change element. Depending on the state of the phase change material, the RF electrodes form a conductive path through the phase change material for an RF signal. To control the state of the phase change material, the RF switch further includes a heater formed from two heater electrodes. The two heater electrodes are configured to draw a current through the phase change element in a direction transverse to the conductive path.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: August 16, 2016
    Assignee: The Regents Of The University Of Michigan
    Inventors: Mina Raieszadeh, Yonghyun Shim, Muzhi Wang
  • Publication number: 20160035973
    Abstract: An RF switch is provided with a direct heating method. The RF switch is comprised of two RF electrodes disposed on opposing sides of a phase change element. Depending on the state of the phase change material, the RF electrodes form a conductive path through the phase change material for an RF signal. To control the state of the phase change material, the RF switch further includes a heater formed from two heater electrodes. The two heater electrodes are configured to draw a current through the phase change element in a direction transverse to the conductive path.
    Type: Application
    Filed: June 5, 2015
    Publication date: February 4, 2016
    Inventors: Mina Raieszadeh, Yonghyun Shim, Muzhi Wang
  • Patent number: 9197188
    Abstract: A wide range tunable capacitor bank is provided. The capacitor bank comprises a variable capacitor, the capacitance value of which is adjustable within a predetermined capacitance range defined by a minimum capacitance value and a maximum capacitance value. The capacitor bank further comprises one or more switched capacitors each electrically connected in circuit to the variable capacitor. The variable capacitor is configured to allow the capacitance value thereof to be adjusted within the predetermined capacitance range and the one or more switched capacitors are configured to be selectively actuated to permit continuous tuning of the capacitor bank over a second capacitance range that is greater than the predetermined capacitance range. Applications in which the capacitor bank may be implemented, and a method of fabricating an integrated system comprising a plurality of passive components, such as, for example, those of the capacitor bank and high quality factor inductors, are also provided.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: November 24, 2015
    Assignee: The Regents of The University of Michigan
    Inventors: Mina Raieszadeh, Yonghyun Shim
  • Patent number: 9097578
    Abstract: An infrared sensor formed from a resonant sensor element having a mechanical resonator and an IR absorber arranged to receive and absorb incident infrared radiation. The resonator includes a temperature-responsive material that exhibits pyroelectric and piezoelectric effects. The IR absorber is thermally coupled to the resonator such that the resonator receives thermal energy from at least some of the incident infrared radiation absorbed by the IR absorber. The resonator has at least one resonant characteristic that varies based on the amount of thermal energy received from the IR absorber by the resonator. A sensor array and infrared sensing method are included that use a plurality of the infrared sensors along with a reference sensor having the same construction as the other sensor elements, except that the sensor either lacks the IR absorber or has it arranged so that it is not exposed to the incident infrared radiation.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: August 4, 2015
    Assignee: The Regents of The University of Michigan
    Inventors: Mina Raieszadeh, Vikrant Jayant Gokhale
  • Publication number: 20140070905
    Abstract: A wide range tunable capacitor bank is provided. The capacitor bank comprises a variable capacitor, the capacitance value of which is adjustable within a predetermined capacitance range defined by a minimum capacitance value and a maximum capacitance value. The capacitor bank further comprises one or more switched capacitors each electrically connected in circuit to the variable capacitor. The variable capacitor is configured to allow the capacitance value thereof to be adjusted within the predetermined capacitance range and the one or more switched capacitors are configured to be selectively actuated to permit continuous tuning of the capacitor bank over a second capacitance range that is greater than the predetermined capacitance range. Applications in which the capacitor bank may be implemented, and a method of fabricating an integrated system comprising a plurality of passive components, such as, for example, those of the capacitor bank and high quality factor inductors, are also provided.
    Type: Application
    Filed: September 13, 2012
    Publication date: March 13, 2014
    Applicant: The Regents of the University of Michigan
    Inventors: Mina Raieszadeh, Yonghyun Shim
  • Publication number: 20120286161
    Abstract: An infrared sensor formed from a resonant sensor element having a mechanical resonator and an IR absorber arranged to receive and absorb incident infrared radiation. The resonator includes a temperature-responsive material that exhibits pyroelectric and piezoelectric effects. The IR absorber is thermally coupled to the resonator such that the resonator receives thermal energy from at least some of the incident infrared radiation absorbed by the IR absorber. The resonator has at least one resonant characteristic that varies based on the amount of thermal energy received from the IR absorber by the resonator. A sensor array and infrared sensing method are included that use a plurality of the infrared sensors along with a reference sensor having the same construction as the other sensor elements, except that the sensor either lacks the IR absorber or has it arranged so that it is not exposed to the incident infrared radiation.
    Type: Application
    Filed: May 14, 2012
    Publication date: November 15, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGAN
    Inventors: Mina Raieszadeh, Vikrant Jayant Gokhale
  • Patent number: 7977136
    Abstract: Disclosed are one-port and two-port microelectromechanical structures including variable capacitors, switches, and filter devices. High aspect-ratio micromachining is used to implement low-voltage, large value tunable and fixed capacitors, and the like. Tunable capacitors can move in the plane of the substrate by the application of DC voltages and achieve greater than 240 percent of tuning. Exemplary microelectromechanical apparatus comprises a single crystalline silicon substrate, and a conductive structure laterally separated from the single crystalline silicon substrate by first and second high aspect ratio gaps of different size, wherein at least one of the high aspect ratio gaps has an aspect ratio of at least 30:1, and is vertically anchored to the single crystalline silicon substrate by way of silicon nitride.
    Type: Grant
    Filed: January 10, 2009
    Date of Patent: July 12, 2011
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Mina Raieszadeh, Pezhman Monadgemi
  • Patent number: 7933112
    Abstract: Disclosed are one-port and two-port voltage-tunable micro-electromechanical capacitors, switches, and filter devices. High aspect-ratio metal micromachining is used to implement very high quality factor (Q) tunable and fixed capacitors, fixed inductors, and low insertion loss tunable and fixed bandpass LC filters. The tunable capacitors can move in the plane of the substrate by the application of DC voltages and achieve greater than 100% of tuning. A combination of low-loss substrate and highest conductivity metal is used to achieve record high Q and low insertion loss at radio frequencies. The disclosed tunable capacitor structure can also be used as a micromechanical switch.
    Type: Grant
    Filed: December 4, 2007
    Date of Patent: April 26, 2011
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Mina Raieszadeh
  • Patent number: 7847669
    Abstract: Disclosed is an integrated tunable inductor having mutual micromachined inductances fabricated in close proximity to a tunable inductor that is switched in and out by micromechanical ohmic switches to change the inductance of the integrated tunable inductor. To achieve a large tuning range and high quality factor, silver is preferably used as the structural material to co-fabricate the inductors and micromachined switches, and silicon is selectively removed from the backside of the substrate. Using this method, exemplary tuning of 47% at 6 GHz is achievable for a 1.1 nH silver inductor fabricated on a low-loss polymer membrane. The effect of the quality factor on the tuning characteristic of the integrated inductor is evaluated by comparing the measured result of substantially identical inductors fabricated on various substrates. To maintain the quality factor of the silver inductor, the device may be encapsulated using a low-cost wafer-level polymer packaging technique.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: December 7, 2010
    Assignee: Georgia Tech Research Corporation
    Inventors: Farrokh Ayazi, Mina Raieszadeh, Paul A. Kohl
  • Publication number: 20100176489
    Abstract: Disclosed are one-port and two-port microelectromechanical structures including variable capacitors, switches, and filter devices. High aspect-ratio micromachining is used to implement low-voltage, large value tunable and fixed capacitors, and the like. Tunable capacitors can move in the plane of the substrate by the application of DC voltages and achieve greater than 240 percent of tuning. Exemplary microelectromechanical apparatus comprises a single crystalline silicon substrate, and a conductive structure laterally separated from the single crystalline silicon substrate by first and second high aspect ratio gaps of different size, wherein at least one of the high aspect ratio gaps has an aspect ratio of at least 30:1, and is vertically anchored to the single crystalline silicon substrate by way of silicon nitride.
    Type: Application
    Filed: January 10, 2009
    Publication date: July 15, 2010
    Inventors: Farrokh Ayazi, Mina Raieszadeh, Pezhman Monadgemi
  • Publication number: 20090002915
    Abstract: Disclosed are one-port and two-port voltage-tunable micro-electromechanical capacitors, switches, and filter devices. High aspect-ratio metal micromachining is used to implement very high quality factor (Q) tunable and fixed capacitors, fixed inductors, and low insertion loss tunable and fixed bandpass LC filters. The tunable capacitors can move in the plane of the substrate by the application of DC voltages and achieve greater than 100% of tuning. A combination of low-loss substrate and highest conductivity metal is used to achieve record high Q and low insertion loss at radio frequencies. The disclosed tunable capacitor structure can also be used as a micromechanical switch.
    Type: Application
    Filed: December 4, 2007
    Publication date: January 1, 2009
    Inventors: Farrokh Ayazi, Mina Raieszadeh
  • Publication number: 20080136572
    Abstract: Disclosed is an integrated tunable inductor having mutual micromachined inductances fabricated in close proximity to a tunable inductor that is switched in and out by micromechanical ohmic switches to change the inductance of the integrated tunable inductor. To achieve a large tuning range and high quality factor, silver is preferably used as the structural material to co-fabricate the inductors and micromachined switches, and silicon is selectively removed from the backside of the substrate. Using this method, exemplary tuning of 47% at 6 GHz is achievable for a 1.1 nH silver inductor fabricated on a low-loss polymer membrane. The effect of the quality factor on the tuning characteristic of the integrated inductor is evaluated by comparing the measured result of substantially identical inductors fabricated on various substrates. To maintain the quality factor of the silver inductor, the device may be encapsulated using a low-cost wafer-level polymer packaging technique.
    Type: Application
    Filed: December 6, 2007
    Publication date: June 12, 2008
    Inventors: Farrokh Ayazi, Mina Raieszadeh, Paul A. Kohl
  • Publication number: 20060001124
    Abstract: Methods and apparatus providing high quality factor (Q) components on low loss substrates. A substrate is fabricated having a plurality of substrate support elements. A bridging layer is formed on the substrate that is supported by the support elements. A component is formed on the bridging layer. CMOS-compatible processing of silicon substrates may be used. One or more cavities comprising high aspect-ratio trenches may be formed using a low-temperature fabrication sequence which reduces the high-frequency losses in silicon at RF frequencies. The cavities (trenches) are subsequently bridged over or refilled with a dielectric to close the open areas and create a rigid low-loss structure. The structures mechanically-robust and are compatible with any packaging technology. An exemplary one-turn 0.8 nH inductor fabricated on trenched silicon support elements exhibited a very high peak Q of 70.6 at 8.75 GHz with a self-resonant frequency larger than 15 GHz.
    Type: Application
    Filed: June 28, 2005
    Publication date: January 5, 2006
    Inventors: Farrokh Ayazi, Mina Raieszadeh