SAR Anti-Jamming Technique Using Orthogonal LFM-PC Hybrid Modulated Signal

Repeater deception jamming is an effective SAR jamming technique. It has been the hot spot of Synthetic Aperture Radar (SAR) Electronic Counter Measures (ECM) research for its ability to generate false targets with low jamming power, which reduces the difficulty of hardware realization of the jammer. Linear format modulated (LFM) signal is the most commonly used radar signal. However it has poor anti-jamming performance for its simple form and high recognition. A new hybrid modulated signal-LFM-PC signal, using phase coded signal modulates LFM signal, is proposed. Then time-domain and frequency-domain characteristics, range resolution, Doppler tolerance, orthogonality and imaging algorithm adaptability of the signal are studied. We put forward an anti-jamming method by generating the LFM-PC signal using a set of orthogonal phased coded signal in different pulse repetition interval (PRI). Because the LFM-PC signal in different PRI is not known to the jammer, which destroys the correlation of the jamming signal and the transmission signal. Simulation results show that the proposed method has a good anti-jamming performance.