A Metasurface With Independent Amplitude–Phase Co-Control for Recognition Deception Based on the Mimicry of Micro-Doppler Signatures and Flicker Mechanisms

Passive radar jamming is a class of attractive approaches that can interfere with radar signals and essentially destroy the detection capability of the radar. In previous passive jamming schemes based on metasurfaces, almost all demonstrated jamming is amplitude invariant and limited to only change phase related properties of the radar echo, which restricts more jamming functions. Here, we report a recognition deception based on an amplitude-phase-independent metasurface. This metasurface can simultaneously achieve similar amplitude attenuation levels for different phase-shifting states as well as small phase fluctuation across different amplitude attenuation levels within a full 360° phase-shifting cycle. Besides that, this metasurface also behaves small inherent internal loss. With such a metasurface, not only a simple false target jamming can be realized, but also the recognition deception based on the imitation of micro-motion features including both micro-Doppler signatures and flicker mechanisms for aerial targets can come true. The independent manipulation functionalities of the metasurface are validated in measurements. Moreover, with numerically derived, time-variant coding sequences, the effectiveness of the recognition deception as different kinds of aerocrafts as well as the same kind of aerocrafts with different numbers of rotors is experimentally demonstrated by mimicking their reflected signals.