Patent ID: 8416062

Claim:
An apparatus for scattering interrogation electromagnetic waves emitted from an RFID reader at one or more interrogation frequencies, the apparatus comprising: a substrate element having a predetermined area; a plurality of unconnected resonant elements each having a resonant frequency, a quality factor, and a response band, the response band being centered at the resonant frequency with a bandwidth defined as the ratio between the resonant frequency and the quality factor, wherein at least one of the interrogation frequencies is within the response band of each resonant element; wherein the plurality of resonant elements are distributed with different orientations within the predetermined area of the substrate element for scattering interrogation electromagnetic waves radiated from an antenna of the RFID reader to one or more RFID tags; and wherein at least one resonant element of the plurality of resonant elements is operable to scatter the interrogation electromagnetic waves from the RFID reader to at least one RFID tag of the one or more RFID tags, the at least one RFID tag having a null-direction of an antenna aligned to a direct propagation direction of the interrogation electromagnetic waves radiated from the RFID reader to the at least one RFID tag, and further wherein the at least one resonant element has a null-direction of an antenna orientated in a direction that is substantially orthogonal to a line extending from a center of the at least one resonant element to a center of the antenna of the RFID reader.