The isolation between the transmitted signal and the reception one of SAR(Synthetic Aperture Radar) jammer is a bottleneck for many DRFM(Digital Radio Frequency Memory) based jammers.This problem is especially important for SAR azimuth deceptive jamming and also for measures against waveform agile SAR ECCM(Electronic Counter-Counter Measures) where SAR jammers need to receive and transmit signal simultaneously within the same pulse.In order to get the jammer’s coupling signal model caused by isolation problem

the mathematical series are employed to describe the specific working process of SAR jammer.Considering the LFM(Linear Frequency Modulation) signal’s time-frequency property and its non-ideal waveform in real application

a method to decouple LFM’s time-frequency coupling and also to compensate the non-ideal waveform is proposed here

which makes the harmful trans-reception coupling component and the useful received signal much easier to be distinguished.This suggests that the jammer’s trans-reception isolation problem can be solved in a much easier way now by only employing filtering and other signal processing technologies.Finally

our method is proved both by the simulation and the data analysis to be effective.