A Novel Amplitude–Phase Synthesis Method for Metasurface-Based Radar Target HRRP Imitation

The radar jamming technology based on metasurfaces has attracted widespread attention in recent years due to its advantages of flexible modulation and low power consumption. However, the deception effect of the radar target characteristics imitation technique is greatly reduced by the limited modulation states of the digital coding metasurface. To address this issue, this article proposes a novel time-domain equivalent amplitude and phase (EAP) generation method that can significantly increase the number of time modulation states of the metasurface without increasing hardware complexity. The time-domain EAP generation model based on the spatial vector synthesis is established first, and theoretical analysis demonstrates that the number of modulation states of 1- and 2-bit phase-coding metasurfaces under vertical incidence can be expanded from 2 to (the number of units +1), and from 4 to the square of (the number of units +1), respectively. Based on the time-domain EAP, a more efficient and accurate metasurface-based target high-resolution range profile (HRRP) imitation scheme compared with the state of the art is proposed, and its superiority is verified through simulations. Experiment results based on a 1-bit phase-coding metasurface further validate the practicality of both the EAP generation method and the EAP-based target HRRP imitation scheme.