Patent ID: 7639178

Claim:
A system for detecting a device; comprising: a transmitter, said transmitter configured to transmit a variable frequency signal to saturate a receiver of a device; a first receiver, said first receiver suitable for receiving an emitted harmonic signal from the device, a second receiver, said second receiver suitable for receiving said emitted harmonic signal from the device; and a processing unit, the processing unit configured to measure a time period between transmission of said signal and receipt of the emitted harmonic signal from the device, said processing unit configured to determine a distance between said system and said device based upon said time period, said processing unit configured to determine a passband representation of said device by said transmitter sweeping a passband of said device upon detection of said device by transmitting multiple signals of various frequencies and determining which harmonic signals coherent to each transmitted signal are received by at least one of said first receiver and said second receiver.