Nonlinear node detector of frequency modulation continuous wave system

Abstract

The invention provides a nonlinear node detector of a frequency modulation continuous wave system. The nonlinear node detector comprises a modulation signal generator used for generating modulation signals, a voltage-controlled oscillator controlled by the modulation signals to generate continuous wave frequency modulation signals, a frequency multiplier used for multiplying the continuous wave frequency modulation signals, a first amplifier used for amplifying the continuous wave frequency modulation signals, a transmitting antenna, a receiving antenna used for receiving echo signals, a second amplifier used for amplifying the echo signals, a mixer utilizing the multiplied continuous wave frequency modulation signals as local oscillator signals and mixing the amplified echo signals with the local oscillator signals to generate beat signals, a filter used for filtering the beat signals, a third amplifier used for amplifying the filtered beat signals and a digital signal processing terminal used for processing the beat signals, analyzing frequency and size of the beat signals, determining whether an electronic target exists in a detection area or not and calculating the distance between the electronic target and the detector. The nonlinear node detector can effectively avoid electromagnetic wave interference signals in environment background, improves detection performance of the electronic target and reduces false alarm rate.

Description

technical field [0001] The invention relates to the technical field of safety protection detection, in particular, the invention relates to a nonlinear node detector adopting a frequency modulation continuous wave system. Background technique [0002] Electronic devices are generally composed of electronic circuits. The most basic element of an electronic circuit is a diode, which is formed by connecting two semiconductor substances. According to the characteristics of the diode, the connection point of the diode is generally called a nonlinear node. With the rapid development of the electronic industry, a large number of diodes, triodes and integrated circuits are used in various electronic devices, so that there are one or more nonlinear nodes in these electronic devices. The nonlinear node detector is to emit high-frequency electromagnetic waves in the searched area to excite the self-excited echoes on the nonlinear nodes in various electronic devices, and then use the r...

AI Technical Summary

Problems solved by technology

[0003] However, with the advancement of electronic science and technology, a large number of electronic devices have been put into use in current production activities. In addition, there are also a large number of messy electromagnetic wave signals in the background of the daily environment. The frequency band (generally 800MHz- 4GHz) there are a large number of other electromagnetic signals of various frequencies, such useless signals often interfere with the normal work of nonlinear junction detectors, resulting in false alarms

[0004] The existing nonlinear node detectors are generally nonlinear node detectors with a point-frequency system, and the frequency of the point-frequency transmission signal sent by it is fixed. will just affect the normal operation of the nonlinear junction detector

In fact, due to the variety of frequencies of interference signals in the environmental background, it is difficult for the existing point-frequency nonlinear node detectors to find a frequency that just avoids the influence of all interference signals to detect the frequency that may cause personal injury. Electronic Targeting of Safety and Information Security Hazards

That is, the existing ordinary nonlinear node detectors cannot work normally in the disturbing electromagnetic environment and the complex use environment with electronic equipment, which affects its further promotion and use in various complex use environments.

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