Abstract: The output to the antenna of an RFID tag or label is disconnected from the balance of the RFID chip by means of a series switch activated in response to a logic command, CLOAK, generated by the RFID chip. Activation of the switch disconnects the output to the antenna of the RFID tag without disconnecting its input. The output to the antenna is thus disconnected for a time sufficient to allow the remaining RFID tags in an RF interrogation field to be identified. However, the input of the antenna remains connected and is capable of receiving at any time, including during the cloaking period commands which can lift the tag out of cloaking and allow it to then selectively output its signal.

Abstract: An RFID interrogator comprises an amplifier configured to amplify signals being transmitted by the RFID interrogator. The RFID interrogator also comprises a bypass path to direct received signals around the amplifier so that the amplifier does no block the reception of signals received from an RFID tag.

Abstract: A location tracking system for tracking the location of items within a controlled area comprises a plurality of RFID tags located according to the required accuracy of the location determinations. Vehicles configured to transport items being tracked include two RFID interrogators configured to acquire RFID information from the plurality of RFID tags and to transmit the RFID tag information to a location authority. The separation the two RFID interrogators is set based on the spacing of the plurality of RFID tags such that the required accuracy results. The location authority can then simply map the RFID tag information to coordinate information stored for each of the plurality of tags to obtain the location of the vehicle and, therefore, the item being transported.

Abstract: An RFID conveyor system comprises one or more wedges designed to allow an RFID scanner to detect and uniquely identify RFID-tagged baggage as they are conveyed through an antenna array. The RFID conveyor system can also be designed to prevent the reading of previous or subsequent bags by using antennas with highly focused RF read fields in conjunction with RF energy absorbing materials, such as RF curtains, designed to eliminate the identification of any baggage located outside of the “read” area.

Abstract: The output to the antenna of an RFID tag or label is disconnected from the balance of the RFID chip by means of a series switch activated in response to a logic command, CLOAK, generated by the RFID chip. Activation of the switch disconnects the output to the antenna of the RFID tag without disconnecting its input. The output to the antenna is thus disconnected for a time sufficient to allow the remaining RFID tags in an RF interrogation field to be identified. However, the input of the antenna remains connected and is capable of receiving at any time, including during the cloaking period commands which can lift the tag out of cloaking and allow it to then selectively output its signal.

Abstract: The invention reduces recovery time in a receiving coil or antenna of an RFID reader by generating a reference voltage that then clamps the node on which the desired signal is monitored. The coil is coupled to parallel channels. One channel has a recovery time or capacitance very much less than the other parallel channel. The two channels have a monitored node which are clamped together or at least close together by means of a Schottky diode. The monitored nodes of both channels are coupled to the inputs of a differential amplifier. The output of the amplifier is the conditioned received signal from the coil used in the reader as the sensed signals from the RFID tags.

Abstract: A flat compact loop pattern provides an antenna for radio frequency identification tags with an enhanced voltage and/or current across two closely adjacently spaced terminals which are disposed on the same side of an insulating substrate. The amount of voltage supplied by the antenna loop to the RFID tag depends not only on the surface area included within the loop but also on the length of the planar loop or winding. The loop is comprised of a serpentine non-crossing wire disposed all on one side of the substrate, typically in the pattern of either a raster patterns in areas adjacent to one or more of the sides of the rectangular substrate, or a radial array of loops extending between the periphery and center of the substrate as the loops are azimuthally advanced around the center like spokes on a wheel or slices of pie.