Abstract: Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

Abstract: Systems and methods to use radar systems for radio frequency identification (RFID) applications. In one embodiment, radar systems are adapted to use RFID communications protocols and methods to enhance the usefulness of radar systems beyond the determination of the presence, distance, direction and/or speed of a vehicle or object, to additionally include the transmission of data such as object identification and additional messages or data.

Abstract: Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

Abstract: Systems and methods to selectively attach and control antennas via diodes and current sources. In one embodiment, a system includes: an RFID reader having a plurality of reader antennas of different polarizations to transmit radio frequency signals; and at least one RFID tag. The RFID tag includes: a plurality of tag antennas of different polarizations; a plurality of diodes coupled to the plurality of tag antennas respectively; a receiver coupled to the plurality of diodes to receive the radio frequency signals from the tag antennas when the diodes are forward biased; and a set of one or more current controllers coupled to the plurality of diodes. In a receiving mode the controllers selectively forward bias the diodes to receive the signals from the RFID reader. In a transmitting mode the controllers selectively change the state of the tag antennas to transmit data via backscattering the radio frequency signals.

Abstract: In one among many embodiments, the invention provides a system including an interrogator communicating to a selected one or more of a number of communications devices. A plurality of communications devices select random values independently of random values selected by other devices. The interrogator transmits a first signal requesting devices within a specified group of devices to respond, the specified group being less than or equal to all of the devices within a field of the interrogator. Devices receiving the first signal respectively determine if the respective device falls within the specified group and, if so, send a reply including a respective random value to the interrogator within a randomly selected time slot of a number of slots; and, if not, do not send a reply. The interrogator determines if a collision occurred between devices that sent a reply. The interrogator also creates a new, different specified group.

Abstract: A shipping container has a passive radio antenna element having internal and external antennas. A connector spanning the wall joins the two antennas. An internal communications device is disposed within the container and an external communications device is disposed external to the container. Another shipping container has a repeater element having internal and external antennas. A repeater unit spans the wall joining the two antennas. A communications device is disposed within the container and another communications device is disposed externally. RF signals are re-radiated by the antennas. Methodology includes emitting RF signals from a communication device disposed at a first location, receiving the signals through an antenna comprised by an antenna element, and re-radiating the signal from a second antenna comprised by the element, where the element spans the wall of a shipping container. The re-radiated signal is received by a second communications device disposed at a second location.

Abstract: A target radio frequency identification (RFID) device may include a receiver to receive valid bits common to a first set of random numbers and to receive a signal indicating a change in a number of time slots from a first number of a plurality of time slots to a second number of a plurality of time slots in which the target device may respond. The target device may include processing circuitry to generate a random number, to determine if the random number is in the first set, to generate a random value, and to randomly select a time slot. The target device may further include a transmitter to communicate a response if the random number is determined to be in the first set, and to communicate the random value during the randomly selected time slot.

Abstract: The present invention provides radio frequency identification devices, remote communication devices, identification systems, communication methods, and identification methods. A radio frequency identification device according to one aspect includes a substrate; communication circuitry coupled with the substrate and configured to receive a wireless signal including an identifier, to process the identifier of the wireless signal and to output a control signal responsive to the processing of the identifier; and indication circuitry coupled with the communication circuitry and configured to receive the control signal and to indicate presence of the radio frequency identification device responsive to the control signal.

Abstract: The present invention teaches a method of manufacturing an enclosed transceiver, such as a radio frequency identification (“RFID”) tag. Structurally, in one embodiment, the tag comprises an integrated circuit (IC) chip, and an RF antenna mounted on a thin film substrate powered by a thin film battery. A variety of antenna geometries are compatible with the above tag construction. These include monopole antennas, dipole antennas, dual dipole antennas, a combination of dipole and loop antennas. Further, in another embodiment, the antennas are positioned either within the plane of the thin film battery or superjacent to the thin film battery.

Abstract: A method of establishing wireless communications between an interrogator and individual ones of multiple wireless identification devices, the method comprising combining tree search and Aloha methods to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision. A system comprising an interrogator, and a plurality of wireless identification devices configured to communicate with the interrogator in a wireless fashion, the respective wireless identification devices having a unique identification number, the interrogator being configured to employ tree search and Aloha techniques to determine the unique identification numbers of the different wireless identification devices so as to be able to establish communications between the interrogator and individual ones of the multiple wireless identification devices without collision by multiple wireless identification devices attempting to respond to the interrogator at the same time.

Abstract: System and methods for identifying a lost or stolen device. In one aspect, a method includes: receiving a plurality of items on a platform configured to support the items for transportation, one or more of the items being registered in a database; interrogating via an interrogation signal transmitted from a radio frequency identification (RFID) reader to one or more RFID tags attached to one or more of the items while on the platform; and communicating with the database over an Internet to identify an item as being missing and associated with the platform, based on a result of interrorgating.

Abstract: RFID tags are identified. In one embodiment, RFID tags may be chosen to respond to an interrogator in accordance with an arbitration scheme. According to one arbitration scheme, each chosen tag may randomly pick a slot value. The interrogator may indicate that the number of slot values is to be adjusted. Each chosen tag may respond to the interrogator with a random number.

Abstract: Methods and apparatus, including computer program products, for an analog RFID system. A radio frequency identification (RFID) device includes an antenna linked to an integrated circuit, the integrated circuit comprising tag circuitry and analog modulation circuitry, a device linked to the integrated circuit, the device generating an analog signal output, and the analog modulation circuitry configured to conditioning the analog signal output.

Abstract: Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

Abstract: Systems and methods to determine kinematical parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, one of a population of RFID tags is selectively instructed by an RFID reader to backscatter the interrogating electromagnetic wave and thus allow the RFID reader to measure the position, speed, acceleration, jerk of the object to which the tag is attached. The RFID reader combines the signal representing the backscattered interrogating electromagnetic wave and the signal representing the interrogating electromagnetic wave transmitted by the RFID reader to determine or monitor one or more of the kinematical parameters of the object.

Abstract: A shipping container has a passive radio antenna element having internal and external antennas. A connector spanning the wall joins the two antennas. An internal communications device is disposed within the container and an external communications device is disposed external to the container. Another shipping container has a repeater element having internal and external antennas. A repeater unit spans the wall joining the two antennas. A communications device is disposed within the container and another communications device is disposed externally. RF signals are re-radiated by the antennas. Methodology includes emitting RF signals from a communication device disposed at a first location, receiving the signals through an antenna comprised by an antenna element, and re-radiating the signal from a second antenna comprised by the element, where the element spans the wall of a shipping container. The re-radiated signal is received by a second communications device disposed at a second location.

Abstract: An RFID device utilizing a single antenna for multiple resonant frequency ranges. RFID device that can include an RFID circuit, and a single antenna coupled to the RFID circuit. The antenna can be configured to operate within multiple frequency ranges for communicating with at least one RFID interrogator according to respective protocols associated with each respective frequency range.

Abstract: A radio frequency identification (RFID) tag includes a base supporting an integrated circuit and a first antenna orthogonal to a second antenna, the first antenna and the second antenna coupled to the integrated circuit, and a first fold in the base that when creased, defines two lobes lying in two planes, a first lobe including a first portion of the first antenna positioned in an x-axis relative to the second antenna oriented along a y-axis, and a second lobe including a second portion of the first antenna positioned in a z-axis relative to the first portion of the first antenna and second antenna.

Abstract: An RFID system in which RFID devices utilize RFID circuits and antennas having unmatched frequency ranges. The system includes an RFID interrogator having multiple interrogator antennas. Each interrogator antenna can be tuned to different respective frequency ranges. The system includes an RFID device having an RFID circuit, and device antennas coupled to the RFID circuit. Each device antenna can be tuned to a respective frequency range that matches only one of the interrogator antennas for communicating with the RFID interrogator according to respective protocols associated with each respective frequency range.

Abstract: A method of establishing wireless communications between an interrogator and individual ones of multiple wireless identification devices, the method comprising utilizing a tree search method to attempt to identify individual ones of the multiple wireless identification devices so as to be able to perform communications, without collision, between the interrogator and individual ones of the multiple wireless identification devices, a search tree being defined for the tree search method, the tree having multiple nodes respectively representing subgroups of the multiple wireless identification devices, wherein the interrogator transmits a command at a node, requesting that devices within the subgroup represented by the node respond, wherein the interrogator determines if a collision occurs in response to the command and, if not, repeats the command at the same node.