Abstract:
An adjustable radio frequency data communications device has a monolithic semiconductor integrated circuit with integrated circuitry, interrogation receiving circuitry provided on the monolithic integrated circuit forming at least part of the integrated circuitry and configured to receive an interrogation signal from the interrogator unit, an antenna electrically coupled to the interrogation receiving circuitry and configured to communicate with the remote interrogator unit, a power source electrically coupled to the integrated circuitry and configured to generate operating power for the communications device, and at least one of the antenna and the interrogation receiving circuitry having reconfigurable electrical characteristics, the electrical characteristics being reconfigurable to selectively tune the at least one of the antenna and the interrogation receiving circuitry within a range of tuned and detuned states to realize a desired receiver sensitivity of the communications device. Additionally, a method for tuning receiver sensitivity and/or transmitter sensitivity according to construction of the above device is disclosed.
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 plurality of battery-operated transceivers encapsulated by lamination to form a sheet of independent transceivers is tested in a two piece fixture that forms an enclosure surrounding each in-sheet transceiver. Each enclosure has an antenna for transmitting a command signal to the transceiver at a known power level and for receiving a reply message from the transceiver containing a power level measurement made by the transceiver. Test methods using the fixture of the present invention are also described. An RFID tag and interrogator may each include a transmitter and a receiver. The tag and interrogator may communicate with each other at different frequency bands and may communicate in accordance with a wireless communication protocol.
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:
Methods and systems of tagging objects and reading tags coupled to objects. At least some of the illustrative embodiments are systems comprising a reading antenna, a tag reader coupled to the reading antenna, and a radio frequency identification (RFID) tag comprising a tag antenna electromagnetically coupled to the reading antenna. The RFID tag couples to an object such as the body of a living organism or a metallic article. Moreover, the tag antenna has a far-field radiation pattern in a direction away from the object that is substantially unaffected by proximity of the RFID tag to the object, and substantially unaffected by which surface of the RFID tag faces the object.
Abstract:
A method of coordinating a plurality of RFID readers includes controlling the RFID readers such that only one of the readers performs an inventory of RFID tags at a time. A system for coordinating a plurality of RFID readers is also provided.
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:
Methods and apparatuses to secure data transmission in a radio frequency identification (RFID) system against eavesdropping, using multiple communication channels. In one embodiment, a method includes communicating key information and cipher text generated based on the key information, or plain text, using a plurality of different, distinct and separate communication channels connected to an RFID tag.
Abstract:
Methods and systems using polarization modulated electromagnetic waves. At least some of the illustrative embodiments are systems comprising a radio frequency identification (RFID) reader, and a RFID tag (the RFID tag communicatively coupled to the RFID reader),. The RFID tag is configured to transmit data to the RFID reader with data encoded in polarization of electromagnetic waves transmitted from the RFID tag.
Abstract:
Methods and systems of RFID tags using RFID circuits and antennas having unmatched frequency ranges. At least some of the illustrative embodiments are RFID tags comprising a RFID circuit configured to operate with an antenna having a first range of resonant frequencies, a tag antenna coupled to the RFID circuit (the tag antenna having a range of resonant frequencies different than the first range of resonant frequencies, the range of resonant frequencies of the tag antenna being a second range of resonant frequencies).