ELECTRONIC MONITORING DEVICE

摘要

PROBLEM TO BE SOLVED: To constitute an electronic monitoring device provided with an antenna for radiating microwave signals to a search territory and receiving the echo signals, a microwave transmitter, an echo signal catching/detecting receiver, a duplexer, and a fixed signal restraint compensation loop based on reflection on a stationary object, and detecting movement of an object, so that the robust construction is possible, and reliability and sensitivity are high. SOLUTION: A duplexer is constituted as a microwave bridge, connected to a controllable negative load 9 for restraining a fixed signal, and/or a receiver is provided with an oscillator 1 and a signal mixer 8 connected to the oscillator 1 on the input side, for converting the frequency of an echo signal to medium frequency f1 .