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.

Abstract: The present disclosure provides a power rectifier for a Radio Frequency Identification tag circuit. The rectifier is constructed from a pair of complementary MOS transistors. Gates of the transistors have predetermined voltages applied to them. The applied voltages bias the transistors to near their active operating region. During the same time additional control signals are applied to the gates of the transistors, the control signals are synchronous, but out of phase, with each other.

Abstract: An Integrated Circuit (IC) for an RFID tag includes two electrically isolated antenna ports for connecting to two antennas, with each antenna port configured to operate at a different frequency range and/or with a different communications protocol. In some embodiments a rectifier coupled to one of the antenna ports is operable to extract energy from an electromagnetic field in a first frequency range, and a demodulator coupled to the other antenna port is operable to demodulate symbols according to an RFID protocol in a second frequency range. In some embodiments the frequency ranges are disjoint, intersecting, or one is a proper subset of the other. In some embodiments each port is coupled to its own rectifier and/or its own modulator and/or its own demodulator. In some embodiments an RFID tag includes the IC and two antennas, each operable in one of the two frequency ranges.

Abstract: The present disclosure provides a power rectifier for a Radio Frequency Identification tag circuit. The power rectifier is constructed from a pair of complementary MOS transistors. Gates of the transistors have predetermined voltages applied to them. The applied voltages bias the transistors to near their active operating regions, while an additional RF control signal is being applied to only one of the gates of the transistors in the complementary pair.

Abstract: RFID tag circuits, tags, and methods are provided for backscattering a received RF wave using a controllable admittance difference between the ON state and the OFF state. The admittance difference is controlled responsive to a control signal. In some embodiments, the control signal is generated responsive to a command. In others, the control signal is generated responsive to detecting the power level of the received RF wave. In those, the inherent behavior of the admittance difference can be shaped as desired. For example, it can be such that the backscatters with advantageously more power when it is away from the reader, and with less power when it is close to the reader, so as to meet regulatory requirements.

Abstract: Radio frequency identification (RFID) reader devices are disclosed. An RFID reader device of one aspect may include a radio frequency (RF) output port operable to allow a plurality of RFID antenna modules to be coupled with the RFID reader device. An RF signal generator of the device may be coupled with the RF output port. The RF signal generator may be operable to generate an RF signal and provide the RF signal to the RF output port. A select signal generator of the device may be operable to generate a select signal. The select signal may be operable to be output to select one or more of the plurality of RFID antenna modules.

Abstract: Apparatus and method for generating a rectified output signal in a RFID tag from first and second alternating signals. A dual-terminal rectifier device has first and second input terminals to which the first and second alternating signals are applied, and further has a gate configured to form a conductive channel to electrically couple the first and second input terminals to the output terminal in response to a gate voltage. The dual-terminal rectifier device is configured to rectify a combination of the alternating input signals applied to the input terminals of the semiconductor device to generate a rectified output signal at an output terminal.

Abstract: An antenna system for a reader configured to interact with RFID tags includes one or more antenna elements electrically coupled to the reader for transmission and reception of RFID signals. In one embodiment the antenna elements include a conductive plate, a first elongate aperture in the plate oriented longitudinally in a first direction, a second elongate aperture in the plate oriented longitudinally in the first direction so as to be generally parallel with the first elongate aperture, a third elongate aperture in the plate oriented longitudinally in a second direction generally perpendicular to the first direction and configured to join the first and second apertures at about the longitudinal middle of the first aperture. Both “h”-shaped and “H”-shaped versions are provided. In another embodiment the antenna element comprises a rectangular slot.

Abstract: A precursor for a Radio Frequency Identification (RFID) tag includes a conductive lead frame with at least three segments, an RFID Integrated Circuit (IC) with at least two antenna terminals, and at least two jumpers. The RFID IC is mounted on at least one of the segments. The antenna terminals are electrically coupled to at least two of the segments, and the jumpers electrically couple the segments such that the coupled segments form a two-turn coil between the antenna terminals of the RFID IC.

Abstract: A Schottky junction diode device having improved performance is fabricated in a conventional CMOS process. A substrate including a material doped to a first conductivity type is formed. A first well is disposed over the substrate. The first well includes a material doped to a second conductivity type opposite that of the first conductivity type. A region of metal-containing material is disposed over the first well to form a Schottky junction at an interface between the region of metal-containing material and the first well. In one embodiment, a first well contact is disposed in a portion of the first well. A second well is disposed over the substrate wherein the second well includes a material doped to the first conductivity type. In one embodiment, the first well and the second well are not in direct contact with one another.

Abstract: RFID reader systems, components, software and methods are provided for use premises that have RFID-tagged items. When a person comes onto an enclosure of the premises already carrying a personal tag, the incoming code of that personal tag is read. When later the person exits the enclosure, they could be transporting some of the items that have actionable codes. The actionable codes can be read, but the incoming code can be removed from them, before the actionable codes are acted upon, in Point-of-Sale or Electronic Article Surveillance systems.

Abstract: RFID tags have an on-chip antenna and an off-chip antenna. One of the antennas can become uncoupled if the proper signal is received, while the other antenna may still operate. The uncoupled antenna can be the larger one, for example the off-chip antenna. Then the tag can then be read only by the smaller antenna, which effectively reduces the range of the RFID tag, but without disabling it entirely.