초록 ▼

An apparatus and a method of transporting energy from a base station to energize a remote RF transponder having an energy store is described, comprising transporting power in pulses of frequencies chosen from a randomly ordered list of frequencies, wherein the time between pulses when little power i

An apparatus and a method of transporting energy from a base station to energize a remote RF transponder having an energy store is described, comprising transporting power in pulses of frequencies chosen from a randomly ordered list of frequencies, wherein the time between pulses when little power is transmitted is less than the time taken for the remote transponder to deplete the energy store.

대표청구항 ▼

[ We claim:] [1.] A method of transporting Radio Frequency (RF) energy to an RF transponder (RF tag, the RF tag comprising at least one tag antenna, a rectifying circuit connected to the tag antenna for receiving energy from the tag antenna, a tag energy store for storing the energy received from th

[ We claim:] [1.] A method of transporting Radio Frequency (RF) energy to an RF transponder (RF tag, the RF tag comprising at least one tag antenna, a rectifying circuit connected to the tag antenna for receiving energy from the tag antenna, a tag energy store for storing the energy received from the rectifying circuit, tag electronics, and means for delivering energy from the tag energy store to the tag electronics, comprising the steps of:(a) transporting for a first time RF electromagnetic wave energy from a base station having a base station antenna to the RF tag, the RF energy having a first frequency f.sub.1 ;then(b) ceasing to transport RF energy during an off time t.sub.o, where the off time t.sub.o is less than a time where the RF tag loses one or more functions; and then(c) transporting for a second time RF electromagnetic wave energy from the base station to the RF tag, the RF energy having a second frequency f.sub.2 different from the first frequency f.sub.1, the tag antenna and the rectifying circuit of the RF tag being adapted for receiving power at frequencies f.sub.1 and f.sub.2.