Patent ID: 7564356

Claim:
A radio frequency identification (RFID) tag to be attached to an object to identify the object or a characteristic or feature thereof from data stored in the tag accessible by an RFID reader, said RFID tag comprising: an application-specific integrated circuit (ASIC), configured to process signals from the RFID reader and return signals related to the stored data; an interdigit AC coupling circuit, in communication with the ASIC; a matching circuit, in communication with the interdigit AC coupling circuit; and an antenna, in communication with the matching circuit, configured to receive signals from the RFID reader and transmit the signals related to the stored data; wherein the interdigit AC coupling circuit and the matching circuit provide an AC coupling and a matching impedance between the ASIC and the antenna respectively; and wherein the interdigit AC coupling comprises a number of pairs of interdigit fingers with a coupling gap between the pairs of interdigit fingers and wherein the number of pairs of interdigit fingers and the coupling gap are selected so that the interdigit AC coupling circuit and the matching circuit provide a matching impedance to an impedance of the antenna.