Jamming of ISAR Imaging With Time-Modulated Metasurface Partially Covered on Targets

The phase information of the echo is essential for inverse synthetic aperture radar (ISAR) imaging. Time-modulated metasurface (TMM) generates time-varying reflection phase that can modulate the phase of echo, thus enabling jamming of ISAR imaging, which has great potential for real applications. In practice, covering the whole target with TMM is difficult to achieve. Consequently, the echo model of a radar target partially covered with a TMM is developed, which extends the model of ISAR jamming with TMM fully covering to a more general and near-realistic case in this letter. Then, the echoes of each component of the target are obtained by electromagnetic simulation, and the time-varying reflection phase of the 1-bit TMM is obtained by experimental testing. Finally, using the abovementioned data, we validate that ISAR image of the component covered metasurface can be blurred using random time modulation sequence. Meanwhile, duplicated components can be produced in the ISAR image using periodic time modulation sequence. Experimental results of range profile jamming confirm the validity of the conclusions in this letter. The partial defocusing or duplicating of the radar target in the ISAR image can reduce the recognized possibility and enhance the jamming performance, effectively.