Patent ID: 7898456
Filing Date: 2011-03-01
Classification: G01S,H01Q

Abstract:
1. Apparatus for detecting and locating hidden objects, comprising: a symmetrical array of five directional antennas arranged along a common plane with radiation patterns pointing in a same general direction, including a central transmit antenna and a pair of receive antennas at each side of the transmit antenna; a transmitter that supplies a high-frequency signal to the transmit antenna, whereby the transmit antenna radiates a beam of high-frequency electromagnetic energy, and whereby the pairs of receive antennas receive electromagnetic energy returned by hidden objects; a phase detector associated with each pair of receive antennas, respectively, for detecting electrical phase differences between receive antenna signals corresponding to the electromagnetic energy received by the associated receive antennas and producing an output dependent upon detected phase differences; and a circuit that determines when the outputs of the phase detectors represent predetermined phase differences and that operates indicator means.