Patents by Inventor Shailendra Srinivas

Shailendra Srinivas 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: 11853826
    Abstract: An RFID IC may operate at a relatively low clock frequency while impedance matching to an antenna is being tuned to increase the amount of power that the IC can extract from an incident RF wave. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna. The IC may power-up with a low clock frequency or reduce its current clock frequency to a lower clock frequency prior to tuning or during the tuning process, and may increase its clock frequency upon completion of tuning or during the tuning process.
    Type: Grant
    Filed: July 19, 2022
    Date of Patent: December 26, 2023
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 11811415
    Abstract: A direct digital synthesizer (DDS) circuit. The circuit includes a first input to receive a first fixed frequency clock signal having a first frequency, a second input to receive a second fixed frequency clock signal having a second frequency lower than the first frequency, and an output to provide an output frequency that is based at least in part on a frequency control word (FCW). The DDS circuit may include a frequency correction circuit having a first input to receive the first clock signal, a second input to receive the second clock signal, and a third input to receive the FCW, and an output to provide a frequency error of the first clock signal, the frequency error determined using the second clock signal and FCW. Alternatively, or in addition to, the DDS circuit may include an all-digital phase lock loop to correct for frequency wander of the first clock signal.
    Type: Grant
    Filed: June 18, 2021
    Date of Patent: November 7, 2023
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventors: Shailendra Srinivas, Joseph D. Cali, Steven E. Turner
  • Publication number: 20220407524
    Abstract: A direct digital synthesizer (DDS) circuit. The circuit includes a first input to receive a first fixed frequency clock signal having a first frequency, a second input to receive a second fixed frequency clock signal having a second frequency lower than the first frequency, and an output to provide an output frequency that is based at least in part on a frequency control word (FCW). The DDS circuit may include a frequency correction circuit having a first input to receive the first clock signal, a second input to receive the second clock signal, and a third input to receive the FCW, and an output to provide a frequency error of the first clock signal, the frequency error determined using the second clock signal and FCW. Alternatively, or in addition to, the DDS circuit may include an all-digital phase lock loop to correct for frequency wander of the first clock signal.
    Type: Application
    Filed: June 18, 2021
    Publication date: December 22, 2022
    Applicant: BAE Systems Information and Electronic Systems Integration Inc.
    Inventors: Shailendra Srinivas, Joseph D. Cali, Steven E. Turner
  • Patent number: 10929734
    Abstract: An RFID IC may operate at a relatively low clock frequency while impedance matching to an antenna is being tuned to increase the amount of power that the IC can extract from an incident RF wave. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna. The IC may power-up with a low clock frequency or reduce its current clock frequency to a lower clock frequency prior to tuning or during the tuning process, and may increase its clock frequency upon completion of tuning or during the tuning process.
    Type: Grant
    Filed: October 10, 2019
    Date of Patent: February 23, 2021
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 10445535
    Abstract: An RFID IC may operate at a relatively low clock frequency while impedance matching to an antenna is being tuned to increase the amount of power that the IC can extract from an incident RF wave. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna. The IC may power-up with a low clock frequency or reduce its current clock frequency to a lower clock frequency prior to tuning or during the tuning process, and may increase its clock frequency upon completion of tuning or during the tuning process.
    Type: Grant
    Filed: May 21, 2018
    Date of Patent: October 15, 2019
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 10002266
    Abstract: An RFID IC may operate at a relatively low clock frequency while impedance matching to an antenna is being tuned to increase the amount of power that the IC can extract from an incident RF wave. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna. The IC may power-up with a low clock frequency or reduce its current clock frequency to a lower clock frequency prior to tuning or during the tuning process, and may increase its clock frequency upon completion of tuning or during the tuning process.
    Type: Grant
    Filed: August 6, 2015
    Date of Patent: June 19, 2018
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Shailendra Srinivas, Jay Kuhn, Ronald A Oliver, Harley Heinrich, Theron Stanford, Christopher J. Diorio
  • Patent number: 9875438
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: January 23, 2018
    Assignee: IMPINJ, INC.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Patent number: 9489611
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: November 8, 2016
    Assignee: IMPINJ INC.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Patent number: 9349090
    Abstract: A tuning circuit in an RFID tag may be used to match antenna and integrated circuit (IC) impedances to maximize the efficiency of IC power extraction from an incident RF wave. The tuning circuit, which requires less power to operate than the IC, adjusts a variable impedance to improve the impedance matching between the IC and the tag antenna and thereby increase the IC power extraction efficiency. The IC may begin operating according to a protocol when it extracts sufficient power from the RF wave or when an optimal impedance matching and power transfer is achieved.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: May 24, 2016
    Assignee: IMPINJ, INC.
    Inventors: Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, John D. Hyde, Christopher J. Diorio
  • Publication number: 20150248604
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Application
    Filed: May 16, 2015
    Publication date: September 3, 2015
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Publication number: 20150227832
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Application
    Filed: August 23, 2013
    Publication date: August 13, 2015
    Applicant: Impinj, Inc.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Patent number: 9053400
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Grant
    Filed: August 23, 2013
    Date of Patent: June 9, 2015
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Patent number: 8952792
    Abstract: A tuning circuit in an RFID tag may be used to match antenna and integrated circuit (IC) impedances to maximize the efficiency of IC power extraction from an incident RF wave. The tuning circuit, which requires less power to operate than the IC, adjusts a variable impedance to improve the impedance matching between the IC and the tag antenna and thereby increase the IC power extraction efficiency. The IC may begin operating according to a protocol when it extracts sufficient power from the RF wave or when an optimal impedance matching and power transfer is achieved.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: February 10, 2015
    Assignee: Impinj, Inc.
    Inventors: Shailendra Srinivas, Jay Kuhn, Ronald A. Oliver, John D. Hyde, Christopher J. Diorio
  • Publication number: 20140073071
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Application
    Filed: August 23, 2013
    Publication date: March 13, 2014
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Publication number: 20140070010
    Abstract: Embodiments are directed to a Radio Frequency Identification (RFID) integrated circuit (IC) having a first circuit block electrically coupled to first and second antenna contacts. The first antenna contact is disposed on a first surface of the IC and the second antenna contact is disposed on a second surface of the IC different from the first surface. The first and second antenna contacts are electrically disconnected from each other.
    Type: Application
    Filed: August 23, 2013
    Publication date: March 13, 2014
    Applicant: Impinj, Inc.
    Inventors: Christopher J. Diorio, Ronald L. Koepp, Harley K. Heinrich, Theron Stanford, Ronald A. Oliver, Shailendra Srinivas
  • Patent number: 8072329
    Abstract: The present disclosure provides examples of a voltage regulator for a Radio Frequency Identification tag circuit. The voltage regulator includes a pair of native transistors. A first native transistor is coupled to a reference voltage and biased to saturation. A resistive element coupled between the gate and the drain of the transistor ensures a sufficient voltage difference between the source and the drain of the first native transistor. The second native transistor, with a gate coupled to the gate of the first native transistor, outputs a regulated voltage.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: December 6, 2011
    Assignee: Impinj, Inc.
    Inventors: Shailendra Srinivas, Jay A. Kuhn
  • Patent number: 7573749
    Abstract: Methods and apparatuses prevent overtunneling in nonvolatile floating gate memory (NVM) cells. An individual cell includes a circuit with a transistor that has a floating gate that stores charge, and a capacitor structure for extracting charge from the gate, such as by tunneling. A counteracting circuit prevents extracting charge from the floating gate beyond a threshold, therefore preventing overtunneling or correcting for it. In one embodiment, the counteracting circuit supplies electrons to the floating gate, to compensate for tunneling beyond a point. In another embodiment, the counteracting circuit includes a switch, and a sensor to trigger the switch when the appropriate threshold is reached. The switch may be arranged in any number of suitable ways, such as to prevent a high voltage from being applied to the capacitor structure, or to prevent a power supply from being applied to a terminal of the transistor or to a well of the transistor.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: August 11, 2009
    Assignee: Virage Logic Corporation
    Inventors: Christopher J. Diorio, Chad A. Lindhorst, Shailendra Srinivas, Alberto Pesavento, Troy N. Gilliland
  • Publication number: 20070171724
    Abstract: Methods and apparatuses prevent overtunneling in nonvolatile floating gate memory (NVM) cells. An individual cell includes a circuit with a transistor that has a floating gate that stores charge, and a capacitor structure for extracting charge from the gate, such as by tunneling. A counteracting circuit prevents extracting charge from the floating gate beyond a threshold, therefore preventing overtunneling or correcting for it. In one embodiment, the counteracting circuit supplies electrons to the floating gate, to compensate for tunneling beyond a point. In another embodiment, the counteracting circuit includes a switch, and a sensor to trigger the switch when the appropriate threshold is reached. The switch may be arranged in any number of suitable ways, such as to prevent a high voltage from being applied to the capacitor structure, or to prevent a power supply from being applied to a terminal of the transistor or to a well of the transistor.
    Type: Application
    Filed: March 29, 2007
    Publication date: July 26, 2007
    Applicant: Impinj, Inc.
    Inventors: Christopher Diorio, Chad Lindhorst, Shailendra Srinivas, Alberto Pesavento, Troy Gilliland
  • Patent number: 7212446
    Abstract: Methods and apparatuses prevent overtunneling in nonvolatile floating gate memory (NVM) cells. An individual cell includes a circuit with a transistor that has a floating gate that stores charge, and a capacitor structure for extracting charge from the gate, such as by tunneling. A counteracting circuit prevents extracting charge from the floating gate beyond a threshold, therefore preventing overtunneling or correcting for it. In one embodiment, the counteracting circuit supplies electrons to the floating gate, to compensate for tunneling beyond a point. In another embodiment, the counteracting circuit includes a switch, and a sensor to trigger the switch when the appropriate threshold is reached. The switch may be arranged in any number of suitable ways, such as to prevent a high voltage from being applied to the capacitor structure, or to prevent a power supply from being applied to a terminal of the transistor or to a well of the transistor.
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: May 1, 2007
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Chad A. Lindhorst, Shailendra Srinivas, Alberto Pesavento, Troy N. Gilliland
  • Publication number: 20050030827
    Abstract: A single-poly PMOS nonvolatile memory (NVM) cell and a method of programming, erasing and reading such a cell are implemented using a single-poly PMOS NVM cell which includes a floating gate injection transistor, a select switch, and a tunneling capacitor having one plate in common with the floating gate of the injection transistor. Methods of altering the number of electrons on the floating gate of the single-poly PMOS NVM cell are used which, with appropriate biasing of the components permit the power terminals of the cell to have appropriate voltages applied to thereby avoid stuck bits and induce hot electrons onto the floating gate of the NVM cell.
    Type: Application
    Filed: September 7, 2004
    Publication date: February 10, 2005
    Inventors: Troy Gilliland, Chad Lindhorst, Christopher Diorio, Todd Humes, Shailendra Srinivas