Interference principle

The principle of jammer is the electronic equipment that transmits or forwards electronic jamming signals, which is used to jam or deceive enemy electronic equipment, so that its efficiency is reduced or even invalid.

Jammer can be divided into: clutter jammer, which suppresses enemy electronic equipment by emitting pure clutter or clutter modulation signal, so that communication signal is interrupted or radar target echo is covered, and the ability to detect signals is lost; Deceptive jammer that deceives, confuses and destroys the normal work of enemy electronic equipment with false signals after receiving enemy signals and integrated jammer with the above two functions.

Jammers can be deployed on the ground, vehicles, ships, planes and missiles. According to the use situation, it can be divided into multiple use and one use (throwing) jammer. The working frequency band of jammer has expanded from centimeter wave and millimeter wave to infrared and laser frequency band, and it is developing in the direction of improving transmitting power, creating effective jamming patterns, adopting computer adaptive control and phased array technology.

General structure of jammer. The overall structure of jammer is shown in the figure. The radar signal passes through the receiving antenna and enters the reconnaissance receiver for amplification. After analysis, the jamming threat radar is found out and the jamming parameters are determined. The guidance and control system controls the jamming signal generator to select the appropriate jamming pattern and jamming frequency, and controls the jamming transmitter to work, so as to generate a high-power jamming signal with noise modulation and radiate it through the transmitting antenna. Due to the high interference power, the transmitted signal will enter the receiver through the receiving antenna, which will affect the reconnaissance guidance in serious cases. Therefore, jamming and reconnaissance guidance often work in time-sharing, and the high-power transmitter will be turned off during reconnaissance.