Improved Interrupted Sampling Repeater Jamming based on DRFM

Interrupted Sampling Repeater Jamming (ISRJ) can be implemented easily based on Digital Radio Frequency Memory (DRFM) technique. An improved method is presented in this paper which has all advantages of traditional ISRJ. Furthermore, the improved ISRJ obtains a train of false targets that precede the true one. The radar radio signal is downshifted and sampled by receive-transmit time-sharing antenna and then stored to digital memory. Its retransmitting signal reserves the coherent property so that a large number of false targets will be achieved after matched filter of the pulse compression radar. The principal and quantitative relation between the false targets and the true one is deduced and analyzed. Simulation illustrates that the improved ISRJ method obtains several false targets ahead of the true one and the amplitude of the main false target decrease compared with the traditional method. The amplitude decrease can be remedied by enhancing the power of transmitting antenna. Imaging results with improved ISRJ method to real SAR raw are shown at last.