A radio frequency identification (RFID) antenna and/or RFID tag circuit may be fabricated on a substrate. The substrate may be a wafer, a die created from a wafer, or an integrated circuit package substrate. The RFID tag may also be distributed between the die and the package substrate in an integrated circuit package. In some embodiments the RFID tag may be fabricated in the lower layers of the substrate and become operational before the rest of the circuitry on the substrate has been fabricated.