Radio frequency identification (RFID) includes far-field systems associated with an RFID interrogator and an RFID tag. The RFID interrogator produces continuous wave (CW) unmodulated signals selected from frequencies comprising a predetermined frequency band. The RFID tag includes reception and transmission antenna circuits, a signal processor, and an oscillator. The reception antenna circuit receives the reception signals from the RFID interrogator. The signal processor determines whether the reception signals correspond to a plurality of tag identification frequencies as a correlation. The signal processor also produces responsive signals in response to the correlation. The oscillator supplies a carrier frequency. The transmission antenna circuit combines the carrier signal with the response signals to produce transmit signals, and then dispatches the transmit signals.