Patent ID: 7884723

Claim:
An RFID (radio frequency identification) tag comprising: a power source that supplies a driving voltage; a continuous wave detector that receives the driving voltage from the power source so as to detect a continuous wave in a signal received from an RFID tag reader; a command detector that selectively receives the driving voltage and detects a command in the signal; a switch that temporarily provides the driving voltage from the continuous wave detector to the command detector to detect the command in the signal if the continuous wave is detected; a wake-up signal detector that detects a wake-up signal in a signal at the output of the command detector if the continuous wave is detected and the command detector temporarily received the driving voltage and receives the signal, wherein a controller supplies a stable driving voltage through the switch to the command detector so as to execute the command detected by the command detector if the continuous wave and the wake-up signal are detected; wherein the controller executes the command detected by the command detector by supplying the stable driving voltage to the command detector through the switch if the continuous wave is detected, and stops the stable driving voltage from being supplied to the command detector if no command is received from the command detector for a predetermined time period; and wherein the switch is external to the controller.