A Method of Same Frequency Interference Elimination Based on Adaptive Notch Filter

The torpedo active electromagnetic fuze is an active electromagnetic detection system, as the distance between the transmitting and receiving antennas is very short, the direct coupling signal will inevitably appear in the receiving signals. This interference has the same frequency as target signal, and is of great harm to the detection system's normal operation. Traditional methods of same frequency interference elimination were analyzed, and it was found that neither of them were suitable for the object studied in this paper, so a method of same frequency interference elimination was put forward based on adaptive notch filter. Its working principle, working process and performance were analyzed; also its numerical value simulation and engineering test had been carried out. The results indicated that as long as the magnitude and phase of the same frequency remained unchanged, it would be effectively eliminated with this method; moreover, this method could be used in a low SNR situation.