A new method for anti-noise FM interference

Noise frequency modulated (NFM) interference causes a disaster to almost all types of radar systems. The echo signal and the interference are overlapped because of the strong energy of the NFM interference, and in the radar receiver system nothing could be detected except the interference. Up to now no good method against NFM has been declared, conventional methods are based on the passive radar to track the interference source. Here a new anti-noise FM method is proposed to suppress the NFM interference, the method multiply the echo signal two times by different reference signals, and results show that the method can eradicate NFM effectively which is useful for detecting and tracking the target. Whatpsilas more, in the presence of several interferences from different directions, the passive Radar can not track the interference source but the method supposed here can work well.