A modulated backscatter radio frequency identification device includes a diode detector configured to selectively modulate a reply signal onto an incoming continuous wave; communications circuitry configured to provide a modulation control signal to the diode detector, the diode detector being configured...http://www.google.co.uk/patents/US7760073?utm_source=gb-gplus-sharePatent US7760073 - RFID tag modification for full depth backscatter modulation
