An electronic article surveillance and identification tag and system is provided. The tag couples energy from a radiated energy source, which comprises first and second radiated signals. A mixing member in the tag mixes the first and second signals to produce a sideband of the first signal, which is...http://www.google.com.au/patents/US6356197?utm_source=gb-gplus-sharePatent US6356197 - Electronic article surveillance and identification device, system, and method
