Abstract: An electronic tag (10) is operable in both an RTF protocol mode and a TTF or TTO protocol mode. Typically, the tag is an RFID tag which includes an antenna (11) acting as a receiver for receiving a signal, and as a transmitter for transmitting a signal.

Abstract: A transponder (28) of a radio frequency identification (RFID) system comprises control circuitry, a response signal generating arrangement and a memory arrangement (22) connected to the control circuitry. The memory arrangement comprises at least a first part (42) and a second part (44). The first part (42) comprises unique identification data (UID) (70) relating to the transponder and which is permanently stored in the first part of the memory arrangement at manufacture of the transponder. The second part (44) is configured to be written to, after manufacture of the transponder. The control circuitry is configured, after energization of the transponder, to cause the response signal generating arrangement automatically to generate a first response signal modulated with data in the first part and data in the second part, to be transmitted by the transponder.

Abstract: A passive transponder (10) includes a resonator circuit (16) to receive a powering signal thereby to provide electrical energy to the transponder (10) by inductive coupling. The resonator circuit (16) is switchable between a high Q factor mode in which an induced voltage in the resonator circuit (16) decays slowly, and a low Q factor mode in which an induced voltage in the resonator circuit (16) decays more quickly. The transponder (10) includes a power storing arrangement (24) to store at least a portion of the electrical energy obtained from the powering signal.

Abstract: A radio frequency identification system comprises a reader associated, in use, with a transmitted beam of radio frequency energy and a plurality of transponders to be energized by the energy and each of which intermittently retransmits a response signal to be read by the reader. A method of monitoring the read quality of the reader comprises the steps of causing the transponders and beam to move relative to one another and defining a sequence of groups of transponders in the beam. For each transponder in a group, receiving the response signals transmitted and recording (68) a read count which is equal to the number of times the response signals was received and read by the reader while the transponder is in the beam. Thereafter computing (70) a statistical distribution of number of transponders against read count in the group. Data associated with the distribution is processed and compared (72) to stored historical data relating to a previously computed distribution for a previous group in the sequence.

Abstract: A radio frequency identification (RFID) system and more particularly a tag comprising a transponder forming parts of such a system. The tag preferably includes a substrate; a transponder mounted on the substrate; the transponder comprising electronic circuitry and an antenna connected to the circuitry; a sense element on the substrate which is sensitive to damage to the substrate and which is connected to a sense input of the circuitry; the antenna comprising a metal layer and the sense element a layer of conductive ink.