| 摘要 |
FIELD: physics, navigation.SUBSTANCE: invention relates to search devices and is designed for detecting objects based on reception of signals resulting from secondary re-radiation with change in the spectrum of the probing signal. The detector has first and second generators which emit probing signals at close frequencies fand f, and a receiver with a receiving antenna which receives signals in a frequency range close to the frequencies fand f. To eliminate nonlinear combination-type interference and interference associated with blocking effects, probing signal antennae further include ferrite valves. Between the receiver and the second probing signal generator, there is a compensator for the second probing signal at the input of the receiver, consisting of two directional couplers, a variable attenuator and a variable phase-changer. A decision on detection of an object with nonlinear elements is made if a combination-type component at frequency 2f-for 2f-fis detected at the input of the receiver. In another mode, the decision is made if the receiver detects a signal at frequency f, which is modulated with frequency F, wherein the probing signal at frequency fis modulated with frequency F.EFFECT: enabling detection of objects with nonlinear elements which may in turn include narrow-band nonlinear objects.1 dwg |
