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 monitoring system incorporates antennas that transmit signals at predetermined frequencies; the transmitted signals are received by tags located in the active monitoring area of the antenna which then transmit signals back to the antenna. The antennas are tuned to each desired frequency prior to driving the antennas to transmit at the desired frequency. The system transmits a range of frequencies in a sequence that uses overlapping frequency steps. The monitoring system is also constructed having a variable configuration resulting in the ability to be reconfigured under program control to conform to varying system requirements. The integrated monitoring system employs programmable formats for reconfiguration such that upon program input from a host computer the system can assume predetermined configurations to conform to the particular tasks for the specific application.

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.