Patents Assigned to Impinj, Inc.
  • Powering RFID tags using multiple synthesized-beam RFID readers
    Patent number: 9652643
    Abstract: Synthesized-beam RFID readers may be used to manage and provide information about RFID tag populations. In one embodiment, two or more synthesized-beam readers synthesize respective RF beams towards a tag location. The synthesized-beam readers may coordinate their pointing by means of a controller, a peer-to-peer network, or by using a master-slave arrangement. The synthesized-beam readers may coordinate their transmissions to increase the RF energy available to a tag at the pointing location.
    Type: Grant
    Filed: March 21, 2016
    Date of Patent: May 16, 2017
    Assignee: IMPINJ, INC
    Inventors: Alberto Pesavento, Christopher J. Diorio
  • Rectifier biasing for self-tuning RFID tags
    Patent number: 9646186
    Abstract: Impedance matching between an RFID IC and an antenna may be tuned to increase the amount of power that the IC can extract from an RF wave incident on the antenna. A tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the IC and the antenna and/or adjusting a bias of a rectifier in the IC. The tuning circuit may adjust the variable impedance and/or the rectifier bias based on predetermined or stored tuning settings. For example, the tuning circuit may retrieve stored tuning settings from a nonvolatile memory (NVM) configured to operate with limited functionality at low power.
    Type: Grant
    Filed: February 12, 2016
    Date of Patent: May 9, 2017
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, Harley K. Heinrich, Charles Peach, Christopher J. Diorio, Theron Stanford
  • RFID integrated circuits with channels for reducing misalignment
    Patent number: 9633302
    Abstract: Embodiments are directed to an RFID tag integrated circuit (IC) having antenna contacts separated by a channel. The channel has a smaller cross-section at its center than at its ends, which facilitates fluid flow from the channel center to the channel ends. During attachment of the IC to an inlay or strap, the channel facilitates the flow of liquid adhesive so as to reduce the turbulence and the propagation velocity associated with the liquid adhesive, thereby reducing misalignment caused by the movement of the IC with respect to the inlay or strap.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: April 25, 2017
    Assignee: Impinj, Inc.
    Inventor: Harley K. Heinrich
  • RFID tag memory check using wireless margin read commands
    Patent number: 9607191
    Abstract: Data stored in nonvolatile memory on a Radio Frequency Identification (RFID) tag integrated circuit may have a “margin” associated with how strongly the data is written to the memory. Upon receiving a wireless margin read command, the RFID IC determines whether the margin for one of more data values stored in memory exceeds a margin threshold. The IC may determine the margin by applying bias voltages or currents to the memory cells storing the data values. If the determined margin does not exceed the margin threshold, the IC may respond with an error code.
    Type: Grant
    Filed: June 11, 2015
    Date of Patent: March 28, 2017
    Assignee: Impinj, Inc.
    Inventors: Charles Peach, Alberto Pesavento, Theron Stanford, Jay Kuhn, Christopher Diorio
  • RFID tags with brand protection and loss prevention
    Patent number: 9607286
    Abstract: Brand-protection codes may be used to maintain authenticity chains for items or tags across a number of different entities. A first entity, such as a tag or item manufacturer, may generate a first brand-protection code (BPC) based on a first key and a tag or item identifier and store the first BPC on a tag associated with an item. A second entity that receives the tag and/or item may attempt to authenticate the first BPC. If the second entity authenticates the first BPC, the second entity may generate an authentication code based on a second key and the first BPC and/or the tag/item identifier, and may write the authentication code to the tag. In some embodiments, the authentication code may be a second brand-protection code, or an exit code that allows the item to exit a facility such as a retail store.
    Type: Grant
    Filed: January 18, 2016
    Date of Patent: March 28, 2017
    Assignee: Impinj, Inc.
    Inventor: Christopher J. Diorio
  • RFID tags with dynamic key replacement
    Patent number: 9565022
    Abstract: A cryptographically-enabled RFID tag stores a primary secret key and derives secondary keys from the primary key. A secondary key may be derived by combining the primary key with one or more other parameters using one or more algorithms. The tag uses a derived secondary key to encrypt or electronically sign a tag response sent to a verifying entity. The verifying entity does not know the derived secondary key, but knows the tag primary key and the parameters and algorithms used to derive the secondary key and can derive all of the potential secondary keys. The verifying entity can then attempt to authenticate the tag or tag response by trying potential secondary keys.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: February 7, 2017
    Assignee: Impinj, Inc.
    Inventors: Matthew Robshaw, Alberto Pesavento, Christopher Diorio
  • RFID tag and reader authentication by trusted authority
    Patent number: 9501675
    Abstract: A Radio Frequency Identification (RFID) reader containing a reader key authenticates an RFID tag containing a tag key by receiving a tag identifier from the tag; challenging the tag with a tag challenge; receiving a tag response based at least on the tag challenge and the tag key but not including the tag key; sending a second message including at least the tag identifier and the tag response to a verification authority; and receiving a reply from the verification authority. The reader and the verification authority may mutually authenticate each other before, during, or after the tag authentication process. The verification authority may notify a designated party if a response is incorrect.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: November 22, 2016
    Assignee: IMPINJ INC.
    Inventors: Christopher J. Diorio, Scott A. Cooper, Matthew Robshaw
  • Low-noise amplifier mixer with coupled inductors
    Patent number: 9503160
    Abstract: A Radio Frequency Identification (RFID) reader configured to perform self-jammer cancellation (SJC) may include an SJC module coupled to a low-noise amplifier (LNA), which in turn may be coupled to a mixer via an LNA-mixer interface. The interface may be implemented with a horizontal matching circuit that includes four inductors magnetically and direct-current (DC) coupled to each other. In some embodiments, the inductors may each be implemented using a different segment of a single inductor.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: November 22, 2016
    Assignee: IMPINJ INC.
    Inventor: John D. Hyde
  • RFID integrated circuits with contact islands
    Patent number: 9495631
    Abstract: A Radio Frequency Identification (RFID) IC may have raised contact islands that include conductive contact pads covering a repassivation layer. The raised contact islands are formed by removing part or all of the repassivation material surrounding the raised contact islands. The repassivation material that is not covered and protected by the contact pads may be removed by a strip process that also removes a masking layer used for IC etching. Singulated RFID ICs may be assembled into an RFID tag using a B-stage adhesive that is applied to the ICs and then partially cured. The ICs are deposited onto preheated inlays. The preheated inlays cause the B-stage adhesive on the ICs to bind to the inlays.
    Type: Grant
    Filed: July 18, 2013
    Date of Patent: November 15, 2016
    Assignee: IMPINJ INC.
    Inventors: Ronald L. Koepp, Harley K. Heinrich, Christopher J. Diorio, Tan Mau Wu
  • RFID integrated circuits with antenna contacts on multiple surfaces
    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
  • Increasing dynamic range of RFID tag self-tuning
    Patent number: 9471816
    Abstract: An RFID tag tuning circuit is capable of tuning the impedance matching between an RFID integrated circuit (IC) and an antenna on an RFID tag to increase the amount of power that the IC can extract from an incident RF wave. The tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the antenna and the IC. Prior to tuning, the variable impedance is set using a voltage output from a tuning switch stage of an IC rectifier.
    Type: Grant
    Filed: May 13, 2015
    Date of Patent: October 18, 2016
    Assignee: IMPINJ, INC.
    Inventors: John Hyde, Theron Stanford, Harley Heinrich, Omer Onen, Charles Peach
  • RFID integrated circuit identifier self-check
    Patent number: 9454680
    Abstract: A Radio Frequency Identification (RFID) tag IC stores an identifier and a check code. The IC determines whether the stored identifier is corrupted by comparing it to the check code. If the stored identifier does not correspond to the check code then the IC may terminate operation or indicate an error. The IC may also reconstruct the correct identifier from the check code.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: September 27, 2016
    Assignee: IMPINJ, INC
    Inventor: Christopher J. Diorio
  • Passive self-jammer cancellation in RFID systems
    Patent number: 9430683
    Abstract: A self-jammer-cancellation circuit in an RFID system uses passive variable capacitance networks to attenuate phase-adjusted carrier signals, which are then combined with a received signal to reduce unwanted carrier signals in the received signal. The self-jammer-cancellation circuit also adjusts the passive variable capacitance networks such that the overall capacitance of each network remains constant or the overall relationship of capacitances between the networks remains constant.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: August 30, 2016
    Assignee: IMPINJ, INC.
    Inventor: John D Hyde
  • Network-enabled RFID tag endorsement
    Patent number: 9405945
    Abstract: A Radio Frequency Identification (RFID) reader may be configured to endorse an RFID tag. The reader receives an identifier from the tag and challenges the tag with a challenge. After receiving a response from the tag, the reader sends a first message including at least the identifier, challenge, and response to an authenticating entity and sends a second message including at least the identifier to a certifying entity. The reader then receives a first reply from the authenticating entity and a second reply from the certifying entity. The second reply may include a certificate associated with the tag, or may identify some property of the tag or an item associated with the tag. In some embodiments, the reader may serve as the authenticating and/or certifying entity.
    Type: Grant
    Filed: April 2, 2015
    Date of Patent: August 2, 2016
    Assignee: IMPINJ, INC.
    Inventors: Christopher J. Diorio, Larry Arnstein, Scott A. Cooper
  • Powering RFID tags using multiple synthesized-beam RFID readers
    Patent number: 9373012
    Abstract: Synthesized-beam RFID readers may be used to manage and provide information about RFID tag populations. In one embodiment, two or more synthesized-beam readers synthesize respective RF beams towards a tag location. The synthesized-beam readers may coordinate their pointing by means of a controller, a peer-to-peer network, or by using a master-slave arrangement. The synthesized-beam readers may coordinate their transmissions to increase the RF energy available to a tag at the pointing location.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: June 21, 2016
    Assignee: IMPINJ, INC.
    Inventors: Alberto Pesavento, Christopher Diorio
  • Self tuning RFID tags
    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
  • RFID loss-prevention using angle-of-arrival
    Patent number: 9349032
    Abstract: An RFID loss-prevention system (LPS) permits authorized items to leave a facility and may perform a security action if an unauthorized item leaves the facility. A checkout reader first authorizes an item tagged with an RFID tag to exit a facility by reading an identifier from the tag, obtaining an exit authorization, and sending the identifier to a database. A reader system configured to direct at least two beams along a facility exit path reads tagged items exiting the facility, determines at least one of a travel direction and a tag location, and uses the determination to indicate that a tag is exiting or has exited the facility. The LPS then uses the database to determine if the exiting/exited tag is authorized to leave the facility.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: May 24, 2016
    Assignee: IMPINJ, INC
    Inventors: Christopher J. Diorio, Alberto Pesavento
  • Broadcast refresh of RFID tag persistence
    Patent number: 9330284
    Abstract: A reader may broadcast a refresh command to a population or subpopulation of tags and thereby refresh and extend the persistence time of a tag flag, such as an inventoried flag. The characteristics, timing, and other details of this broadcast refresh command may be determined based on the state of a reader, environmental, tag-population, and/or tag-capability conditions and parameters. The refresh command may be a Select command of the Gen2 Specification, in which case parameters of the Select command specify the refresh operation.
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: May 3, 2016
    Assignee: IMPINJ, INC.
    Inventor: Christopher J. Diorio
  • RFID tag assembly methods
    Patent number: 9317799
    Abstract: RFID tags are assembled through affixing an antenna to an integrated circuit (IC) by forming one or more capacitors coupling the antenna and the IC with the dielectric material of the capacitor(s) including a non-conductive covering layer of the IC, a non-conductive covering layer of the antenna such as an oxide layer, and/or an additionally formed dielectric layer. Top and bottom plates of the capacitor(s) are formed by the antenna traces and one or more patches on a top surface of the IC.
    Type: Grant
    Filed: December 26, 2013
    Date of Patent: April 19, 2016
    Assignee: IMPINJ, INC.
    Inventors: Ronald L. Koepp, Ronald A. Oliver, William T. Colleran, Yanjun Ma, Jay M. Fassett, Vincent C. Moretti
  • RFID tags and readers employing QT command to switch tag profiles
    Patent number: 9305195
    Abstract: RFID readers transmit a Quiet Technology (QT) command to RFID tags causing at least one of the tags to transition between a private profile and a public profile. When a tag is inventoried in the private profile, it replies to the reader with contents from its private memory. When a tag is inventoried in the public profile, it replies to the reader with contents from its public memory, where the contents of the public memory may be a subset and/or modified version of the private memory contents, or entirely different altogether. The tag's profile can be switched again by another QT command from the reader, or following a loss of power at the tag. An access password and/or a short-range mechanism may be employed to allow only authorized readers to transition tag profiles or interrogate the private memory contents of tags in the public profile.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: April 5, 2016
    Assignee: IMPINJ, INC.
    Inventors: Christopher J. Diorio, Theron Stanford, Scott A. Cooper, Harley K. Heinrich, Chad A. Lindhorst, Kambiz Rahimi