Patent ID: 7876225

Claim:
A transponder apparatus, comprising: an electronic device, said electronic device being switchable between an inactive, sleep state and an active state; a power source in electronic communication with said electronic device, said power source providing power to said electronic device; a switch having an antenna for receiving at least one RF signal, said switch converting said at least one RF signal into at least one DC signal; and a filtering circuit in electronic communication with said switch, wherein said at least one DC signal is provided to said filtering circuit, wherein responsive to receiving said at least one DC signal said filtering circuit analyzes said at least one DC signal and determines whether said at least one DC signal has a predetermined format, wherein said predetermined format comprises a predetermined number of bursts, each of said bursts having a predetermined duration, and wherein said filtering circuit provides a wake-up signal to said electronic device to cause said electronic device to move from said inactive, sleep state to said active state only if it is determined that said at least one DC signal has said predetermined format.