An RFID echo cancellation assembly includes: a circulator defining a transmission path from a transmit module to an antenna module, and a reception path from the antenna module to a receive module; a combiner on the reception path between the circulator and the receive module; a variable reflector for applying a cancellation signal to the combiner; a controller for setting an operational parameter at the variable reflector according to an attribute of a transmitted signal from the transmit module; and a coupler defining a segment of the transmission path between the transmit module and the circulator, and a cancellation path between the variable reflector and the combiner. The coupler couples a portion of the transmitted signal to the variable reflector, whereupon the variable reflector generates the cancellation signal based on the operational parameter, for transmission to the combiner via the cancellation signal path.

Exemplary embodiments include RF integrated circuit (RFIC) chips including programmable on-chip element swapping circuitry, channel swapping circuitry, and/or phase rotation circuitry to allow a common software implementation or parameter computation to be used across multiple products having different arrangements and orientations of RFICs and elements.

The present disclosure provides collaborative radiofrequency identification (RFID) readers that employ code division multiple access (CDMA) encoding to simultaneously broadcast to and read responses from tags in an overlapping reading zone with improved data synchronization and read yield rates. In some embodiments, a harmonic backscattering scheme is used to enable the system to have a much higher signal-to-noise ratio (SNR) and sensitivity, while the reader CDMA protocol can be integrated with an initial TDMA polling process or alternative tag CDMA scheme.

A wireless tag communication device includes an antenna configured to transmit a carrier wave and receive a response wave output from a wireless tag with respect to the carrier wave and to specify a position of the wireless tag to be searched based on a radio wave intensity of the response wave received by the antenna. The device includes: a radio wave controller configured to switch the carrier wave between a first and second carrier wave to be transmitted in a first and second polarization direction respectively; and a comparator configured to compare a first and second radio wave intensity of a first and second response wave respectively output from the wireless tag with respect to the first and second carrier waves respectively, and the radio wave controller switches the carrier wave between the first carrier wave and the second carrier wave based on a comparison result of the comparator.

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.

Systems and methods are provided for automatically detecting passive components in communications systems using radio frequency identification (RFID) tags. A coupling circuit is provided in a system between a communications network and an RFID tag. The RFID tag is associated with a passive element of a distributed antenna system (DAS). The coupling circuit can allow an RFID signal received from an RFID transmitter over the communications network to be transported to the RFID tag. The coupling circuit can substantially prevent mobile communication signals on the communications network from being transported to the RFID tag.

A method for collision avoidance in a multi-reader environment comprising a plurality of Radio Frequency Identification (RFID) interrogators, the method comprises each of the plurality of interrogators entering a quiet state during which none of the interrogators transmits, each of the plurality of interrogators selecting a transmit time after the quiet period during which each of the interrogator will attempt to transmit, each of the plurality of interrogators monitoring their associated receive path, an interrogator of the plurality of interrogators transmitting an instruction during its selected transmit time indicating the beginning of a session when the interrogator does not detect data on its receive path prior to its select transmit time, the interrogator comparing its receive path to its transmit path when it transmits the instruction, the interrogator returning to the quiet state when the receive path does not match the transmit path, and the interrogator completing the session when the receive path matches the transmit path.

What is described is an Radio Frequency Identification (RFID) tag configured for communicating with an Radio Frequency Identification (RFID) reader, wherein the RFID tag is configured to receive a query command from the RFID reader, to measure a duration of a TRcal signal comprised by the query command, and to determine an individual Backscatter Link Frequency for communicating with the RFID reader based on the measured duration of the TRcal signal. The invention also refers to an RFID reader and to a corresponding method.

A system for cataloguing items disposed within a predefined volume; each item of the items having associated therewith a tag; each tag having a unique identifier; each tag including: a tag radio transmitter having a predefined tag transmission range a tag radio receiver having a predefined tag reception range a response logic device; the system further including a tag interrogator; the tag interrogator including: a database an interrogation logic device a tag interrogator transmitter having a predefined tag interrogator transmission range a tag interrogator radio receiver having a predefined tag interrogator reception range; the tag radio receiver of a first tag receiving communication from the tag radio transmitter of a second tag when the tag radio receiver of the first tag is within the predefined tag transmission range of the second tag and when the second tag is within the predefined tag reception range of the first tag.

According to one embodiment, according to one embodiment, an IC card executing a command from a processing apparatus includes a communication unit and a processing unit. The communication unit transmits/receives data to/from the processing apparatus. Upon receiving, through the communication unit, a first command requesting transmission of data in a first frame not including a start code or an end code, the processing unit transmits data in the first frame through the communication unit.