Patents Assigned to Sirit Inc.
  • Patent number: 8248212
    Abstract: The present disclosure includes a method and system for pipelining processes in an RF reader. In some implementations, a method includes receiving, from a transponder, a reply to an initial command. A physical (PHY) layer and a media control access (MAC) layer are pipelined to initiate transmission of a subsequent command during demodulation of the transponder reply.
    Type: Grant
    Filed: May 24, 2007
    Date of Patent: August 21, 2012
    Assignee: Sirit Inc.
    Inventor: Thomas J. Frederick
  • Patent number: 8228173
    Abstract: The present disclosure is directed to a system and method for interrogating radio frequency tags. In some implementations, a method includes A method includes successively polling, for a specified number of inventory cycles, a plurality of Radio Frequency Identification (RFID) tags in a first state. At least a first subset of the plurality of RFID tags transitions from the first state to a second state in response to the poll. After the specified number of inventory cycles, a command is transmitted to update at least a second subset of the plurality of RFID tags from the second state to first state. The plurality of RFID tags are subsequently polled after transmitting the update command.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: July 24, 2012
    Assignee: Sirit Inc.
    Inventors: David Ross Missimer, Thomas J. Frederick, George D. Cruickshanks, Steven C. Lin
  • Patent number: 8226003
    Abstract: The present disclosure includes a system and method for adjusting parameters associated with leakage signals. In some implementations, an RFID reader includes an RF antenna, a transmitter section, a receiver section, a control module and a cancellation noise reduction (CNR) section. The transmitter section is coupled to the RF antenna and operable to generate a transmit signal to be transmitted by the RF antenna. The receiver section is coupled to the RF antenna and operable to receive a receive signal from the RF antenna. In addition, the receiver section further includes a de-rotation module and a control module. The de-rotation module is operable to de-rotate, by ?, an in-phase signal and quadrature signal associated with the leakage signal. The control module is operable to generate control signals used to produce a signal for reducing the leakage signal in a receive path of the reader. The CNR section is operable to subtract from the reduction signal from the leakage signal.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: July 24, 2012
    Assignee: Sirit Inc.
    Inventors: Thomas J. Frederick, Joseph P. Repke
  • Patent number: 8169312
    Abstract: The present disclosure is directed to determining speeds of radio frequency tags. In some implementations, a method includes sampling a Radio Frequency (RF) signal from an RFID tag at a plurality of different times as the RFID tag approaches an RFID reader and recedes from the RFID reader. A phase of the RF signal is determined for each of the plurality of different times based, at least in part, on the sampled RF signal. A speed of the RFID tag is determined based, at least in part, on the determined phase for the sampled signal for each of the plurality of different times.
    Type: Grant
    Filed: January 9, 2009
    Date of Patent: May 1, 2012
    Assignee: Sirit Inc.
    Inventor: Thomas J. Frederick
  • Publication number: 20070066224
    Abstract: An RFID reader, comprising a high-efficiency Class-C power amplifier having an input, an output, and a supply voltage, a modulator coupled to the supply voltage of the Class-C power amplifier, and an RF carrier signal coupled to the input of the Class-C power amplifier. The modulator changes the supply voltage of the Class-C power amplifier resulting in highly controlled amplitude modulation of the RF carrier signal at the output of the Class-C power amplifier.
    Type: Application
    Filed: February 27, 2006
    Publication date: March 22, 2007
    Applicant: Sirit, Inc.
    Inventors: Loek d'Hont, Bernard Barink
  • Publication number: 20070066223
    Abstract: A method for use in a RFID reader, the method comprising providing an output signal from an amplifier of a transmitter, attenuating the output signal via a step attenuator, detecting and comparing the attenuated output signal to a reference value, and adjusting power to the amplifier until the attenuated output signal is substantially equal to the reference value. The attenuated output signal drives a local oscillator signal of a receiver thereby canceling noise generated by the transmitter in the receiver.
    Type: Application
    Filed: February 27, 2006
    Publication date: March 22, 2007
    Applicant: Sirit, Inc.
    Inventors: Loek D'Hont, Bernard Barink