METHOD AND DEVICE FOR DETECTING SEARCH OBJECTS COMPRISING METAL CONTACTS IN NONLINEAR SHORT-RANGE RADARS

摘要

FIELD: radio engineering, communication.;SUBSTANCE: method is performed by processing the signal reflected from the search object in the spectral area in the narrow frequency band by means of cross-timing noncoherent or coherent spectrum accumulation of the reflected signal from the search object, and the search object sensing occurs at two carrier frequencies ƒ₁ and ƒ₂, and the detection occurs due to cross-timing accumulation of the reflected signal spectrum in the area of the combination frequencies of the second (ƒ₂-ƒ₁) and the third (2ƒ₁-f₂) orders with the preset threshold calculated by the noise conditions without the search object, in this case the values of the carrier frequencies are selected from the conditions of obtaining a narrower directional diagram at the same size of the antennas, and the values of the obtained combination frequencies are removed from the most used frequency bands, such as cellular communication and television broadcasting. The method is implemented with the device consisting of two transmitters with transmitting antennas and two receiving channels corresponding to the detection of the search objects with a nonlinear transformation of the second (ƒ₂-ƒ₁) and the third (2ƒ₁-f₂) orders, each of them consists of a series-connected receiver with a bandpass filter, an analog-digital converter, a converter in the spectral range, a detector, the second input of which is coupled to the control voltage source, a drive, the drive outputs of the two channels are connected to the first and the second inputs of the interchannel drive with the threshold device, the output of which is the device output.;EFFECT: increasing a signal-to-noise ratio, and thus increasing the range and detection probability of the search objects.;2 cl, 6 dwg