초록 ▼

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 receive

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.

대표청구항 ▼

[ We claim:] [1.] A method for conserving power in a radio frequency identification device defined by a single integrated circuit including a microprocessor and receiver, the method comprising in the single integrated circuit periodically switching from a sleep mode to a receiver-on mode and perform

[ We claim:] [1.] A method for conserving power in a radio frequency identification device defined by a single integrated circuit including a microprocessor and receiver, the method comprising in the single integrated circuit periodically switching from a sleep mode to a receiver-on mode and performing the following tests to determine whether to further switch to a microprocessor-on mode, in which more power is consumed than in the receiver-on mode, because a valid radio frequency signal is present:(a) determining if any radio frequency signal is present and, if so, proceeding to step (b); and, if not, returning to the sleep mode;(b) determining if the radio frequency signal is modulated and has a predetermined number of transitions per a predetermined period of time and, if so, proceeding to step (c); and, if not, returning to the sleep mode; and(c) determining if the modulated radio frequency signal has a predetermined number of transitions per a predetermined period of time different from the predetermined time of step (b) and, if so, switching from the receiver-on mode to the microprocessor on mode; and, if not, returning to the sleep mode.