Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: The present application describes an electronically powered postage stamp or mailing label and including a radio frequency identification (RFID) device and system mounted between the opposing and facing major surfaces thereof. The RFID device and system includes an integrated circuit transceiver chip which is connected to and powered by a thin flat battery cell and is operated with a thin film RF antenna, all of which are mounted in side-by-side relationship on a thin base or support layer. These thin flat components are mounted in an essentially two dimensional planar configuration well suited for incorporation into the planar structure of a postage stamp or a mailing label. In addition, the RFID transceiver chip may be replaced with an electro-optically operated IC chip using, for example, LEDs or laser diodes for the propagation of light signals to an interrogator.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

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.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A frequency doubler includes a first Gilbert cell, a second Gilbert cell coupled to the first Gilbert cell, a frequency generator configured to apply a first sinusoidal wave to the first Gilbert cell, and a phase shifter applying a sinusoidal wave shifted from the first sinusoidal wave to the second Gilbert cell. A method of doubling frequency without using a feedback loop includes providing a first Gilbert cell, providing a second Gilbert cell coupled to the first Gilbert cell, applying a first sinusoidal wave to the first Gilbert cell, and applying a sinusoidal wave shifted from the first sinusoidal wave to the second Gilbert cell.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A system for locating an individual in a facility, the system comprising a portable wireless transponder device borne by the individual; an interrogator; and a plurality of antennas distributed in the facility, the antennas being selectively separately connected to the interrogator, the interrogator when connected to any of the antennas having a communications range covering less than the area of the entire facility, the interrogator being configured to repeatedly transmit a wireless command to the portable wireless transponder device using alternating antennas, the portable wireless transponder device being configured to transmit data identifying the portable wireless transponder device in response to a command if the portable wireless transponder device is within communications range of the antenna sending the command, the individual being locatable by determining with which antenna the interrogator was able to establish communications with the portable wireless transponder device.

Abstract: An antenna circuit configured for use in a radio frequency data communications device has an antenna constructed and arranged to transfer electromagnetic waves, the electromagnetic waves corresponding to a signal carried by the antenna and generated from a signal source. A Schottky diode is electrically coupled in serial relation with the antenna, and in operation the signal is applied serially across the antenna and the diode in direct relation with electromagnetic waves transferred by the antenna. A bias current supply is also electrically coupled to the Schottky diode and is configurable to deliver a desired bias current across the current. The diode is responsive to the bias current to realize a desired diode impedance such that a desired impedance match/mis-match is provided between impedance of the diode and impedance of the antenna when the signal is applied across the antenna circuit, which selectively tunes the antenna circuit by imparting a desired power transfer therein.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

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.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A system for locating an individual in a facility, the system comprising a portable wireless transponder device borne by the individual; an interrogator; and a plurality of antennas distributed in the facility, the antennas being selectively separately connected to the interrogator, the interrogator when connected to any of the antennas having a communications range covering less than the area of the entire facility, the interrogator being configured to repeatedly transmit a wireless command to the portable wireless transponder device using alternating antennas, the portable wireless transponder device being configured to transmit data identifying the portable wireless transponder device in response to a command if the portable wireless transponder device is within communications range of the antenna sending the command, the individual being locatable by determining with which antenna the interrogator was able to establish communications with the portable wireless transponder device.

Abstract: An adjustable radio frequency data communications device has a monolithic semiconductor integrated circuit with integrated circuitry, interrogation receiving circuitry provided 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.

Abstract: A method of forming an integrated circuit including a Schottky diode includes providing a substrate of a first conductivity type, defining a region of a second conductivity type relative to the substrate and forming an insulator over the second conductivity type region. The method also includes removing an area of the insulator for definition of a contact hole, and removing an area encircling the contact hole and forming highly doped regions of the second conductivity type in second conductivity type regions encircling the contact hole. The method further includes depositing a Schottky metal in the contact hole and annealing the metal to form a suicide interface to the second conductivity type region.

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.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

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.