A conductive structure for use with a RFID device having a metallic mass that is below a standard detection threshold of a metal detector and a method of manufacturing the same is disclosed herein. The conductive structure preferably comprises a pair of dipole arms extending from a tuning loop, wherein each of the pair of dipole arms terminates in a load end. The conductive structure may be manufactured from a printed metallic ink, or by cutting, lasering, or etching a metal foil. The conductive structure is modified to reduce overall thickness and metallic mass of the device as much as possible, while still maintaining an acceptable level of performance. Portions of the load ends may also be hollowed out to further reduce the conductive structure's metallic mass.

An RFID inlay includes an RFID module and an antenna. The RFID module includes an RFIC and an antenna sharing circuit provided between the RFIC and the antenna. The RFIC includes a power receiving terminal to which power induced upon receipt of an electromagnetic wave for power reception is input and a transmitting terminal from which a transmission signal for RFID is output. Moreover, the antenna receives the electromagnetic wave for power reception and generates an electromagnetic wave for RFID.

A mobile device includes a smartcard controller that does not rely on power received from an interrogating RF field. The mobile device also includes a small inductive device capable of inductive coupling with an RFID reader. The smartcard controller includes circuitry to modulate an impedance of a port coupled to the inductive element when in the presence of an interrogating RF field at substantially 13.56 MHz.

A tuning assembly for an RFID chip includes an input port, a control unit, and a plurality of capacitors connected in parallel between the input port and the control unit. A selector circuit is coupled to each capacitor and to the control unit and is configured to selectively allow and prevent current flow through any of the capacitors in response to commands from the control unit, thereby adjusting the capacitance of the RFID chip. The commands include a command to always allow current flow through a capacitor, another command to always prevent current flow through a capacitor, and a third command to selectively allow and prevent current flow through a capacitor (e.g., for automatic adjustment of the capacitance of the RFID chip). The control unit may be programmed before or after the RFID chip is coupled to an antenna, including after a fully assembled RFID label has been attached to an article.

It is described an RF communication device comprising: i) an RF antenna functionality; ii) at least one antenna pad connected to the RF antenna functionality; iii) a further functionality which is not an RF antenna functionality; and iv) at least one non-antenna pad electrically connected to the further functionality.

The antenna pad and the non-antenna pad are arranged to be short-circuited with each other, and the non-antenna pad is electrically connected via a connection line to the further functionality within the RF communication device.

Further, a method of manufacturing an RF communication device is described.

In some embodiments, an RFID device includes a reactive strap having an RFID chip and a conductive ring connected to the RFID chip. The RFID device may further include an antenna configured to be coupled to the reactive strap, and a tuning block set positioned in the vicinity of the reactive strap, a resonant frequency of the RFID device being determined at least in part by at least one of the shape of the tuning block set and the position of the tuning block set relative to at least the reactive strap.

A non-contact communication medium according to one disclosed embodiment includes a memory unit, a power generation unit, a power monitoring unit, and a capacitance control unit. The power generation unit includes a resonant circuit and a rectification circuit, and generates electric power to be supplied to the memory unit. The resonant circuit includes an antenna coil and resonant capacitance unit having a variable capacitance value, and the rectification circuit rectifies a resonant output of the resonant circuit. The power monitoring unit includes a current adjustment element, a reference voltage generation source, and an operational amplifier. The operational amplifier controls the current adjustment element such that an output voltage of the rectification circuit is equal to a reference voltage from the reference voltage generation source. The capacitance control unit is configured to control the resonant capacitance unit on the basis of an output of the operational amplifier.

A label with RFID function comprises a support layer and an RFID inlay with an RFID chip and an antenna connected to the RFID chip. The RFID inlay is arranged on the support layer. The antenna comprises at least one capacitive element on which the resonant frequency of the antenna depends. By adding the at least one capacitive element to the antenna, the read/write range of the RFID inlay can be increased.

A method includes transmitting, by a radio frequency identification (RFID) reader, a series of RF signals to a plurality of RF receiver circuits in a time sequence. The first RF signal commands the plurality of RF receiver circuits to remain silent when received signal strength of the first RF signal corresponds to a power level greater than a first power level. The method further includes receiving one or more sets of responses from one or more sets of RF receiver circuits of the plurality of RF receiver circuits in response to the series of RF signals. The method further includes determining an area of interest based on the one or more sets of responses, determining a set of power levels corresponding to the area of interest, and transmitting a second series of RF signals to the plurality of RF receiver circuits in a second time sequence.

A voltage limiter incorporated in a radio frequency identification (RFID) integrated circuit (IC) for a RFID tag is disclosed. The RFID IC includes a radio frequency (RF) rectifier and a clock generator. The RF rectifier is configured to convert an AC signal received from an antenna incorporated in the RFID tag to a DC signal. The voltage limiter includes a current sink device coupled between output of the RF rectifier and ground and a charge pump to control conduction of current through the current sink device to limit output voltage of the RF rectifier to a predefined voltage level.