Patent ID: 9052370
Filing Date: 2015-06-09
Classification: G01N,G01R

Abstract:
1. An apparatus comprising: a portal, defined by one or more conductive surfaces; at least one wire loop, disposed adjacent one or more of the conductive surfaces; a radio frequency transmitter, to generate a plurality of time varying electromagnetic fields within the portal, the electromagnetic fields induced by two or more chirped radio frequency signals at selected phases, selected power levels, and selected chirp start and chirp stop frequencies that include nuclear quadrupole resonant frequencies (NQR) of a material of interest; a coupler coupled to the radio frequency transmitter at an input port, to the at least one wire loop at an output port, and to a receiver at both a signal port and a reference port, the receiver signal port providing a signal (SIG) representing quadrupole resonant emissions from a substance within the portal, and the receiver reference port providing a reference (REF) representative of the output of the radio frequency transmitter; and a signal processor, for further processing signals received on the receiver reference and signal ports, the processor further providing: a downconverter, for downconverting the SIG and REF signals using chirp signals with corresponding phases used by the transmitter, and providing downconverted SIG and REF signals; a decimator, for decimating the downconverted SIG and REF signals, to provide decimated SIG and REF signals; an S an end point decomposition function, for operating on endpoints of the S a phase filter, for operating on the decomposition samples, to provide filtered received samples; and a matched filter correlator, for matched filtering the received samples against an expected NQR frequency response.