Patent ID: 8912788

Claim:
A method for detecting presence of a substance comprising: disposing at least one conductive surface to define a space; disposing at least one conductive wire within the space adjacent the conductive surface; driving the conductive wire with a radio frequency chirp transmitter to create a time varying electromagnetic field within the space at a first average power level; detecting resulting coherent emissions at the first average power level; driving the conductive wire with a radio frequency chirp transmitter to create a time varying electromagnetic field within the space at a second average power level different from the first average power level; detecting resulting coherent emissions at the second average power level; comparing the coherent emissions detected at the first and second average power levels to determine properties of a substance occupied within the space; repeating the steps of driving the conductive wire with multiple radio frequency chips where each chirp includes one or more resonant frequencies characteristic of expected responses for certain materials of interest; and further feeding a radio frequency chirp signal through a plurality of amplifiers arranged in parallel; combining the outputs of the plurality of amplifiers prior to driving the conductive wire; thereby generating a series of radio frequency chirp signals with a selected one of the first or second power levels, a selected one of a sine or cosine relative phase, and a selected frequency range; and demultiplexing the series of radio frequency chirp signals prior to applying them to the plurality of amplifiers.