Abstract: A radio frequency identification device includes a transceiver having a resonant circuit, a rectifier, a charge pump, a state machine, and a transmitter. The resonant circuit includes an antenna and has a resonant frequency. The rectifier is coupled to the resonant circuit to provide a rectified signal in response to energy from the antenna. The charge pump is enabled in response to the rectified signal to provide a first logic signal. The state machine provides a second logic signal in response to the first logic signal. The transmitter includes an amplifier coupled to the resonant circuit to form a Colpitts oscillator that is enabled by the second logic signal to transmit a response signal for identifying the radio frequency identification device.

Abstract: Methods and apparatus for high throughput wireless cells and networks are described. The wireless cells may be equipped with multiple radios. Antennas may be arranged into overlapping and non-overlapping patterns. Channels may be assigned to foster servicing clients, and inter-cell communication. Attenuation may be used to decrease interference. Networks may be formed using a variety of methods and apparatus.

Abstract: Methods and apparatus for high throughput wireless cells, capable of functioning as access points, are described. The wireless cells may be equipped with multiple radios to increase the amount of throughput available through a single wireless cell. Multiple antennas attached to the radios through RF switches may enable the wireless cell to service multiple clients simultaneously. The physical sectors of the antennas may overlapped to form virtual sectors that provide greater flexibility in client load management and in simultaneously servicing multiple clients. Attenuators may reduce interference from foreign wireless cells or clients. Systems and methods for assigning minimally interfering channels to either physical sectors or to radios to reduce interference between adjacent sectors and overlapping sectors are also disclosed. An antenna horn may also allow any antenna to be used as a directional antenna and may enable the antenna's angle of coverage to be adjusted.

Abstract: An object identification system includes a monitor and a plurality of transceivers that communicate over a common medium. The monitor includes a first transmitter, a first receiver, and a processor. Each transceiver includes a resonant circuit, a transmitter, a receiver, and an antenna coupled to the resonant circuit. The processor performs a method for performing transceiver communication that includes the steps of: (a) transmitting from the first transmitter a first frequency for a first duration; (b) after lapse of the first duration, receiving via the first receiver a response signal from at least one of the resonant circuits; (c) determining a second frequency from the received response signal; and (d) performing transceiver communication using the second frequency.

Abstract: A system includes an identification circuit, a grid antenna, a receiver, and a processor. The identification circuit includes resonant circuits formed on a substrate within a perimeter. Identification may be based on a quantity or physical arrangement of detected resonant circuits within the perimeter. One resonant circuit provides a reference signal. Any resonant circuit may be tuned in accordance with the reference signal by the addition or subtraction of reactance formed on the substrate. A capacitance of a first group of capacitors located outside a turn of an inductor is roughly equal to a capacitance of a second group of capacitors located inside the turn. Any resonant circuit may also be tuned by affixing a resonance modifying element, for example a sticker, to the identification circuit. The grid antenna provides antenna field patterns, one for each cell location. The receiver communicates with the identification circuit via the grid antenna.

Abstract: A locator according to various aspects of the present invention includes a receiver and a processor. The receiver receives several signals, each signal having respective indicia of identification device presence within a respective communication pattern. The processor performs a method for determining whether a first identification device is located within a zone. The method includes the following steps performed in any order. A first step of determining, in response to receiver signals, a respective reliability of communication between the receiver and a plurality of identification devices. The plurality includes the first identification device and at least one second identification device. A first and a second communication pattern each respectively has a periphery such that communication with a provided identification device when located beyond the periphery is less reliable than communication with the provided identification device when located within the periphery.

Abstract: Monitoring systems and protocols are disclosed that are flexible in mode operation and format depending on the environment in which they are used. Such monitoring systems and protocols are able to change their utilization automatically, or by received instruction to do so. A location detection system includes one or more low frequency transmitters, one or more radio frequency monitoring tags and one or more receiving devices. The low frequency transmitter transmits location identification information, such as the transmitter ID, to a tag in the vicinity of the transmission. The tag relays the transmitter ID using a higher frequency transmission sent from the tag to the receiver. Communication protocols are disclosed that enable deciphering of multiple tag transmissions starting simultaneously.

Abstract: An object identification system includes a monitor and a plurality of transceivers that communicate over a common medium. The monitor includes a first transmitter, a first receiver, and a processor. Each transceiver includes a resonant circuit, a transmitter, a receiver, and an antenna coupled to the resonant circuit. The processor performs a method for performing transceiver communication that includes the steps of: (a) transmitting from the first transmitter a first frequency for a first duration; (b) after lapse of the first duration, receiving via the first receiver a response signal from at least one of the resonant circuits; (c) determining a second frequency from the received response signal; and (d) performing transceiver communication using the second frequency.

Abstract: An object identification system includes a monitor and a plurality of transceivers that communicate over a common medium. The monitor includes a first transmitter, a first receiver, and a processor. Each transceiver includes a resonant circuit, a transmitter, a receiver, and an antenna coupled to the resonant circuit. The processor performs a method for performing transceiver communication that includes the steps of: (a) transmitting from the first transmitter a first frequency for a first duration; (b) after lapse of the first duration, receiving via the first receiver a response signal from at least one of the resonant circuits; (c) determining a second frequency from the received response signal; and (d) performing transceiver communication using the second frequency.

Abstract: An object identification system includes a monitor and a plurality of transceivers that communicate over a common medium. The monitor includes a first transmitter, a first receiver, and a processor. Each transceiver includes a resonant circuit, a transmitter, a receiver, and an antenna coupled to the resonant circuit. The processor performs a method for performing transceiver communication that includes the steps of: (a) transmitting from the first transmitter a first frequency for a first duration; (b) after lapse of the first duration, receiving via the first receiver a response signal from at least one of the resonant circuits; (c) determining a second frequency from the received response signal; and (d) performing transceiver communication using the second frequency.

Abstract: A carrier, as used for example to transport several radio frequency identification devices, includes a circuit having an antenna and a series capacitor for tuning the antenna. Enhanced transceiver communication results when transceivers are placed in the carrier. Alternately, a carrier may include first and second antenna circuits, each having a capacitor for tuning the respective antenna. The two circuits may cooperate so that energy received in a first pattern is re-radiated in a second pattern for further enhanced transceiver communication, such as detection of the presence of the RFID device within the carrier.

Abstract: An improved information storage and identification tag includes a substrate, an input mechanism disposed on the substrate and configured to receive a query signal, an output mechanism disposed on the substrate, and a response circuit disposed on the substrate. The response circuit is disposed in operative communication with the input mechanism and the output mechanism and is configured to output via the output mechanism at least one selectable response code in response to receipt of a query signal by the input mechanism.

Abstract: A portable platform system for connecting an external module having a module connector to a portable electronic platform having a flat panel display, a central processing unit and a system bus includes at least two docking bays disposed on a rear side of the flat panel display including at least first, second, and third rails and an electrical connector. An external module of a first width is slid in between the first and second adjacent rails to be secured to the rear side of the fiat panel display, and the module connector is connected to the electrical connector of the docking bay to electrically connect the module to the central processing unit via the system bus.