Abstract: RFID tag ICs in a population can adjust the impedance values used to backscatter-modulate reply signals to increase the distribution or spread of backscattered signal parameters, thereby facilitating the recovery of collided tag replies. An RFID tag IC may adjust its impedance value(s) based on a reader command or independently.

Abstract: A Radio Frequency Identification (RFID) integrated circuit (IC) is at least partially covered by a repassivation layer that is, in turn, at least partially covered by a large, electrically conductive contact pad. The repassivation layer is disposed so as to leave uncovered at least one IC contact. The large contact pad is disposed so as to cover the IC IC contact. The large contact pad forms a first galvanic coupling to the IC contact and a second galvanic coupling to a tag antenna. The surface area of the first galvanic coupling is substantially smaller than the surface area of the second galvanic coupling.

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. A substrate of the RFID IC, or a portion of the IC substrate, electrically couples the first circuit block to at least one of the first and second antenna contacts. The IC includes one or more interfaces or barrier regions that at least partially electrically isolate the first circuit block from the rest of the IC substrate.

Abstract: Embodiments are directed to mitigating power-based impedance changes in Radio Frequency Identification (RFID) tags. The intrinsic impedance of components in an RFID tag front-end may change as incident RF power on the tag changes, causing the input impedance of the front-end to change and altering the RF properties of the RFID tag. A number of approaches can be used to mitigate input impedance variations due to power variations. One approach involves adjusting the operating point of one or more components in the RFID tag front-end to change their intrinsic impedances so as to counteract or mitigate the RF-power-based input impedance variation.

Abstract: Embodiments are directed to mitigating power-based impedance changes in Radio Frequency Identification (RFID) tags. The intrinsic impedance of components in an RFID tag front-end may change as incident RF power on the tag changes, causing the input impedance of the front-end to change and altering the RF properties of the RFID tag. A number of approaches can be used to mitigate input impedance variations due to power variations. One approach involves adjusting the operating point of one or more components in the RFID tag front-end to change their intrinsic impedances so as to counteract or mitigate the RF-power-based input impedance variation.

Abstract: A Radio Frequency Identification (RFID) integrated circuit (IC) is at least partially covered by a repassivation layer that is, in turn, at least partially covered by a large, electrically conductive contact pad. The repassivation layer is disposed so as to leave uncovered at least one IC contact. The large contact pad is disposed so as to cover the IC IC contact. The large contact pad forms a first galvanic coupling to the IC contact and a second galvanic coupling to a tag antenna. The surface area of the first galvanic coupling is substantially smaller than the surface area of the second galvanic coupling.

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. A substrate of the RFID IC, or a portion of the IC substrate, electrically couples the first circuit block to at least one of the first and second antenna contacts. The IC includes one or more interfaces or barrier regions that at least partially electrically isolate the first circuit block from the rest of the IC substrate.

Abstract: Embodiments are directed to mitigating power-based impedance changes in Radio Frequency Identification (RFID) tags. The intrinsic impedance of components in an RFID tag front-end may change as incident RF power on the tag changes, causing the input impedance of the front-end to change and altering the RF properties of the RFID tag. A number of approaches can be used to mitigate input impedance variations due to power variations. One approach involves adjusting the operating point of one or more components in the RFID tag front-end to change their intrinsic impedances so as to counteract or mitigate the RF-power-based input impedance variation.

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.

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.

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.

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.

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.

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.

Abstract: An Integrated Circuit (IC) for an RFID tag and a tag including such an IC are provided where the IC includes at least two rectifiers and two antenna ports for connecting to two respective antennas with at least three of the four antenna terminals not sharing a reference potential of the IC. According to other embodiments, the antenna ports are also electrically isolated from each other.

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.

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.

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.

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.

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.