Abstract: A method in one embodiment comprises scanning a zone in an active mode at a first power level for identifying presence of a tag; and scanning portions of the zone in a passive mode at a second power level for again identifying presence of the tag. A system in another embodiment comprises an interrogator for scanning a zone in an active mode at a first power level for identifying presence of a tag; wherein the interrogator also scans portions of the zone for again identifying presence of the tag. A method in another embodiment comprises scanning zones of an area in an active mode for identifying the zone in which the tag is located; and scanning portions of the zone in which the tag is located in a passive mode for identifying the portion of the zone in which the tag is located.

Abstract: A Radio Frequency Identification (RFID) device according to one embodiment of the present invention includes a rechargeable solid state battery, control circuitry coupled to the rechargeable solid state battery, and a power source for recharging the rechargeable solid state battery.

Abstract: A system according to one embodiment of the present invention includes a first clock signal generator generating a first clock signal at a first frequency, and a second clock signal generator generating a second clock signal at a second frequency that is higher than the first frequency. The first clock signal is used to calibrate the second clock signal generator. An RFID device according to another embodiment of the present invention includes a crystal controlled first clock signal generator generating a first clock signal at a first frequency, a second clock signal generator generating a second clock signal at a second frequency that is higher than the first frequency, and an activate circuit. The second clock signal generator is inactive until activated by the activate circuit. The first clock signal is used to calibrate the second clock signal generator. Methods are also presented.

Abstract: RFID-based systems and methods are presented. A portable electronic device according to one embodiment of the present invention includes an electrical system, a controller coupled to the electrical system, a display screen coupled to the electrical system, input devices coupled to the electrical system, and an RFID tag coupled to the electrical system such that removal or disablement of the tag causes disablement of at least some functionality of the device. A Radio Frequency Identification (RFID) system according to an embodimient of the present invention includes an RFID device tag coupled to a device and an RFID user tag associated with a user. The device tag is associated with the user tag. At least some functionality of the device is disabled based on whether or not a presence of the user tag is detected within a vicinity of the device tag.

Abstract: A system, method and computer program product according to one embodiment are provided for calibrating an RFID interrogator. A signal is sent from an interrogator to a calibration device. A backscatter signal is received from the calibration device. The backscatter from the calibration device is analyzed. An outgoing signal strength of the interrogator is adjusted based on the analysis. In a system, method and computer program product according to another embodiment, the interrogator is set to selectively respond to tags returning a backscatter signal strength selected based on the analysis. In a system, method and computer program product according to another embodiment, comparison criteria is selected based on the analysis of the backscatter signal. An RF device is instructed to store the comparison criteria, which is then used by the RF device to selectively respond to an interrogator signal having at least a desired strength.

Abstract: A Radio Frequency Identification (RFID) tag according to one embodiment includes a controller for setting one or more alarm states upon occurrence of one or more alarm conditions, and a visual display device under control of the controller, the visual display device providing a visual, audible, and/or tactile indicator of an alarm condition when an alarm state is set. The visual, audible, and/or tactile indicator of the alarm condition optionally can only be reset by an authorized entity, or cannot be reset.

Abstract: A Radio Frequency (RF) device such as a Radio Frequency Identification (RFID) tag according to one embodiment includes a Digital to Analog Converter (DAC) for generating a reference signal based on a stored digital comparison criteria value, and a mechanism for comparing an incoming signal to the reference signal. The device performs an action such as backscattering based on the comparison. Additional systems and methods are also disclosed.

Abstract: A method for identifying an approximate location of a radio frequency tag includes scanning zones of an area in an active mode at a first power level for identifying the zone in which the tag is located, and scanning portions of the zone in which the tag is located in a passive mode at a second power level for identifying the portion of the zone in which the tag is located. An RFID system includes a plurality of RFID tags and an RFID interrogator in communication with the RFID tags.

Abstract: A Radio Frequency Identification (RFID) tag for use with a vehicle according to one embodiment includes a housing adapted for permanent or detachable coupling to the vehicle, control circuitry coupled to the housing, and a battery for providing power to the control circuitry. A secondary power source is also present for recharging the battery. A memory stores information relating to at least one of the vehicle and an owner of the vehicle. The capability of recharging the battery greatly extends the active (self-powered) life of the tag. Systems for tracking ownership of objects, servicing of vehicles, and other applications, as well as methods are also presented.

Abstract: A Radio Frequency Identification (RFID) tag according to one embodiment includes a controller, a sensor in communication with the controller, a local power source for providing power to the controller, and a user input device for receiving manual input from a user. A function is selectable by manipulation of the user input device. An RFID tag according to another embodiment of the present invention includes a controller having activate circuitry, the activate circuitry being for detecting a valid activate command in an incoming signal and causing the tag to wake from a hibernate state. An electronic display device is in communication with the controller. A local power source provides power to the controller. A user input device receives manual input from a user. The tag is normally in a hibernate state. Manipulation of the user input device wakes the tag from the hibernate state and/or allows function selection.