Patents by Inventor Stefon Shelton
Stefon Shelton 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).
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Patent number: 11938515Abstract: The teachings of the present disclosure enable the manufacture of one or more piezoelectric micromachined ultrasonic transducers (PMUTs) having a resonant frequency of a specific target value and/or substantially matched resonant frequencies. In accordance with the present disclosure, a flexible membrane of a PMUT is modified to impart a desired parameter profile for stiffness and/or mass to tune its resonant frequency to a target value. The desired parameter profile is achieved by locally removing or adding material to regions of one or more layers of the flexible membrane to alter its geometric dimensions and/or density. In some embodiments, material is added or removed non-uniformly across the structural layer to realize a material distribution that more strongly affects membrane stiffness than mass. In some embodiments, material having a specific residual stress is added to, and/or removed from, the membrane to define a desired modal stiffness for the membrane.Type: GrantFiled: December 21, 2018Date of Patent: March 26, 2024Assignee: InvenSense, Inc.Inventors: Fabian Goericke, Stefon Shelton, Benedict Costello
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Publication number: 20240049602Abstract: A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a substrate having an opening therethrough and a membrane attached to the substrate over the opening. An actuating structure layer on a surface of the membrane includes a piezoelectric layer sandwiched between the membrane and an upper electrode layer. The actuating structure layer is patterned to selectively remove portions of the actuating structure from portions of the membrane to form in a central portion proximate a center of the open cavity and three or more rib portions projecting radially outward from the central portion.Type: ApplicationFiled: October 17, 2023Publication date: February 8, 2024Inventors: Andre Guedes, Fabian Goericke, Stefon Shelton, Benedict Costello, David Horsley
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Patent number: 11844282Abstract: A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a substrate having an opening therethrough and a membrane attached to the substrate over the opening. An actuating structure layer on a surface of the membrane includes a piezoelectric layer sandwiched between the membrane and an upper electrode layer. The actuating structure layer is patterned to selectively remove portions of the actuating structure from portions of the membrane to form a central portion proximate a center of the open cavity and three or more rib portions projecting radially outward from the central portion.Type: GrantFiled: February 26, 2020Date of Patent: December 12, 2023Assignee: InvenSense, Inc.Inventors: Andre Guedes, Fabian Goericke, Stefon Shelton, Benedict Costello, David Horsley
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Patent number: 11800804Abstract: A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.Type: GrantFiled: August 26, 2022Date of Patent: October 24, 2023Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Bernhard Boser, David Horsley, Richard Przybyla, Ofer Rozen, Stefon Shelton
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Patent number: 11711067Abstract: A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.Type: GrantFiled: February 18, 2020Date of Patent: July 25, 2023Assignee: InvenSense, Inc.Inventors: Stefon Shelton, Andre Guedes, Richard Przybyla, Meng-Hsiung Kiang, David Horsley
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Publication number: 20230152433Abstract: A robotic cleaning appliance includes a housing to which is coupled a surface treatment item and a sensor assembly with first and second transducers and an acoustic interface. The first sonic transducer transmits sonic signals through an acoustic interface and out of a first acoustic opening toward a surface beneath the robotic cleaning appliance. The sonic signals reflect from the surface as corresponding returned signals received by the second sonic transducer via a second acoustic opening port of the acoustic interface. A first plurality of annular rings is defined in the external surface around the first acoustic opening port and a second plurality of annular rings is defined in the external surface around the second acoustic opening port. The pluralities of annular rings attenuate direct path echoes from a subset of the transmitted sonic signals which attempt to travel across the external surface to the second acoustic opening port.Type: ApplicationFiled: November 15, 2022Publication date: May 18, 2023Applicant: InvenSense, Inc.Inventors: Tony LEI, Joe Youssef, Daniela Hall, Ben Eovino, Stefon Shelton
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Publication number: 20230053609Abstract: A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.Type: ApplicationFiled: August 26, 2022Publication date: February 23, 2023Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Bernhard Boser, David Horsley, Richard Przybyla, Ofer Rozen, Stefon Shelton
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Patent number: 11508346Abstract: A package design for a micromachined ultrasound transducer (MUT) utilizing curved geometry to control the presence and frequency of acoustic resonant modes is described. The approach consists of reducing in number and curving the reflecting surfaces present in the package cavity to adjust the acoustic resonant frequencies to locations outside the band of interest. The design includes a cavity characterized by a curved geometry and a MUT mounted to a side of a substrate facing the cavity with a sound emitting portion of the MUT facing an opening in the substrate. The substrate is disposed over an opening of the cavity with the substrate oriented such that the MUT located within the cavity.Type: GrantFiled: May 23, 2018Date of Patent: November 22, 2022Assignee: InvenSense, Inc.Inventors: Stefon Shelton, Andre Guedes, David Horsley
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Patent number: 11462677Abstract: A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.Type: GrantFiled: November 26, 2019Date of Patent: October 4, 2022Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Bernhard Boser, David Horsley, Richard Przybyla, Ofer Rozen, Stefon Shelton
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Patent number: 11292030Abstract: A piezoelectric micromachined ultrasound transducer (PMUT) is disclosed. The device consists of a flexible membrane that is connected to a rigid substrate via flexures. The flexures are defined by slots etched through the perimeter of the membrane. These features release the stress present on the structural layers of the membrane, making it less sensitive to residual stress. The flexures are designed to act as torsion springs so that the membrane's vibration mode shape is highly curved in the piezoelectric actuation area, thereby increasing the electromechanical coupling.Type: GrantFiled: December 13, 2018Date of Patent: April 5, 2022Assignee: CHIRP Microsystems Inc.Inventors: David Horsley, Andre Guedes, Stefon Shelton, Richard Przybyla
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Patent number: 11005025Abstract: A piezoelectric micromachined ultrasonic transducer (pMUT) device may include a piezoelectric membrane transducer designed to have lower sensitivity to residual stress and reduced sensitivity to geometric variations arising from the backside etching process used to release the membrane. These designs allow some of its key feature to be adjusted to achieve desired characteristics, such as pressure sensitivity, natural frequency, stress sensitivity, and bandwidth.Type: GrantFiled: June 16, 2017Date of Patent: May 11, 2021Assignee: CHIRP MICROSYSTEMS, INC.Inventors: David Horsley, Andre Guedes, Stefon Shelton, Richard Przybyla, Meng-Hsiung Kiang
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Publication number: 20200338592Abstract: The teachings of the present disclosure enable the manufacture of one or more piezoelectric micromachined ultrasonic transducers (PMUTs) having a resonant frequency of a specific target value and/or substantially matched resonant frequencies. In accordance with the present disclosure, a flexible membrane of a PMUT is modified to impart a desired parameter profile for stiffness and/or mass to tune its resonant frequency to a target value. The desired parameter profile is achieved by locally removing or adding material to regions of one or more layers of the flexible membrane to alter its geometric dimensions and/or density. In some embodiments, material is added or removed non-uniformly across the structural layer to realize a material distribution that more strongly affects membrane stiffness than mass. In some embodiments, material having a specific residual stress is added to, and/or removed from, the membrane to define a desired modal stiffness for the membrane.Type: ApplicationFiled: December 21, 2018Publication date: October 29, 2020Inventors: Fabian GOERICKE, Stefon SHELTON, Benedict COSTELLO
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Publication number: 20200270122Abstract: A micromechanical system (MEMS) device package comprising a substrate and a first enclosure including a first cavity, coupled to the substrate. Wherein a transverse dimension of the first cavity relative to the substrate is configured to reduce undesirable acoustic modes within the first cavity and the first cavity comprises an acoustic port. A MEMS device is located inside the first cavity and an Application Specific Integrated Circuit (ASIC) is communicatively coupled to the MEMS device and located outside the first cavity.Type: ApplicationFiled: May 12, 2020Publication date: August 27, 2020Inventors: Stefon Shelton, Fabian Goericke
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Patent number: 10751755Abstract: An apparatus comprises an ultrasonic transducer having a first and second electrode and switches which configured to selectively connect the first and second electrodes to a transmit voltage source or to a receive amplifier. The switches are configured to selectively connect a first input of the amplifier to the first electrode of the transducer and to selectively connect a second input of the amplifier to the second electrode of the transducer. The switches are also configured to selectively connect the voltage source to the first and second electrodes of the transducer. The transducer may include a piezoelectric layer attached to and sandwiched between the first electrode and the second electrode, and a flexible membrane attached to the first electrode. The piezoelectric layer may be patterned to form an annular ring at the outer diameter of the flexible membrane.Type: GrantFiled: March 22, 2017Date of Patent: August 25, 2020Assignee: Chirp Microsystems, Inc.Inventors: David A. Horsley, Andre Guedes, Meng-Hsiung Kiang, Richard Przybyla, Stefon Shelton
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Publication number: 20200266798Abstract: A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.Type: ApplicationFiled: February 18, 2020Publication date: August 20, 2020Inventors: Stefon Shelton, Andre Guedes, Richard Przybyla, Meng-Hsiung Kiang, David Horsley
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Publication number: 20200194658Abstract: A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a substrate having an opening therethrough and a membrane attached to the substrate over the opening. An actuating structure layer on a surface of the membrane includes a piezoelectric layer sandwiched between the membrane and an upper electrode layer. The actuating structure layer is patterned to selectively remove portions of the actuating structure from portions of the membrane to form a central portion proximate a center of the open cavity and three or more rib portions projecting radially outward from the central portion.Type: ApplicationFiled: February 26, 2020Publication date: June 18, 2020Inventors: Andre Guedes, Fabian Goericke, Stefon Shelton, Benedict Costello, David Horsley
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Publication number: 20200194661Abstract: A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.Type: ApplicationFiled: November 26, 2019Publication date: June 18, 2020Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Bernhard Boser, David Horsley, Richard Przybyla, Ofer Rozen, Stefon Shelton
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Patent number: 10573289Abstract: A system and method use an array of ultrasonic transducers to emit and receive sound in a phased array fashion by using acoustic waveguides to achieve a desired acoustic radiation and reception pattern. A chip package attached to an acoustic transducer array includes acoustic waveguides coupled to acoustic ports. Each waveguide is coupled between a corresponding acoustic transducer and a corresponding acoustic port. A spacing of a pair of acoustic ports is different than a spacing of a corresponding pair of acoustic transducers.Type: GrantFiled: May 1, 2017Date of Patent: February 25, 2020Assignee: CHIRP MICROSYSTEMS, INC.Inventors: Richard Przybyla, Andre Guedes, Stefon Shelton, Meng-Hsiung Kiang, David Horsley
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Patent number: 10562069Abstract: A piezoelectric micromachined ultrasound transducer (PMUT) is disclosed. The PMUT consists of a flexural membrane that is piezoelectrically actuated. These membranes are formed on a first substrate that is bonded to a second substrate. The two substrates are separated by an air gap to allow the PMUT to vibrate. Several methods for joining the two substrates are described.Type: GrantFiled: January 13, 2017Date of Patent: February 18, 2020Assignee: CHIRP MICROSYSTEMS, INC.Inventors: David A. Horsley, Andre Guedes, Meng-Hsiung Kiang, Richard J. Przybyla, Stefon Shelton
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Patent number: 10566949Abstract: A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.Type: GrantFiled: November 3, 2016Date of Patent: February 18, 2020Assignee: CHIRP MICROSYSTEMS, INC.Inventors: Stefon Shelton, Andre Guedes, Richard Przybyla, Meng-Hsiung Kiang, David Horsley