Shift Frequency Jamming of LFM Signal Based on Inter-modulation Interference of Mixer Diode

Frequency-shifting is an effective deception jamming mode to linear frequency modulated(LFM) signal.In condition of ambiguous time relationship between the jamming signal and echo signal,the value of frequency-shifting is beyond control.Aiming at this problem,the method of frequency-shifting realization by inter-modulation interference of two jamming signal in mixer diode was brought forward.The value of frequency-shifting could be controlled by difference-frequency of two jamming signals,and had no relation to time delay between the jamming signal and the goal signal.Theoretic analysis indicated that,when two jamming signal get acrossed mixer diode together with the echo signal,the produced inter-modulation interference contained a product term of difference-frequency of the echo signal and that of the jamming signal.Then,the frequency-shifting could be carried into reality by difference-frequency of two jamming signal.The computer simulation result tallied with theoretic analysis perfectly.