Flexible Conformal Multifunctional Time‐Varying Phase‐Modulated Metasurface with Polarization Control for Radar Feature Transformation

Abstract

Reconfigurable metasurfaces have shown unprecedented capabilities in controlling electromagnetic (EM) waves in recent years and play an essential role in information manipulation. However, most research on reconfigurable metasurfaces is limited to planar rigid structures, with only one control function and suitable for specific single polarization. Achieving simultaneous control of phase, polarization, and frequency in the conformal structure has significant practical implications in many applications, but remains obviously challenging. In this paper, a flexible multifunctional time‐varying phase‐modulated metasurface (MTPM) with orthogonal polarization control is proposed for conformal applications to manipulate the spectrum distribution. It enables time encoding capability in controlling the phase characteristics of x‐ and y‐polarized EM waves individually by switching the bias voltage of the PIN diode in two directions. Discrete harmonic spectrum and continuous Doppler frequency shifts are implemented separately on two orthogonal polarizations by applying different time coding sequences. As a practical application, a conformal MTPM for radar feature transformation is explored. Multiple discrete false targets and defocusing phenomena can be realized respectively for x‐ and y‐polarized waves. Both simulated and measured results verify the validity of the proposed method and prototype.

A spatiotemporal encoding metasurface design for manipulation of integrated radiation-scattering characteristic

“…In addition to redistribution of scattering field in the spatial domain, the scattering field can be redistributed in the frequency domain by time modulation technique. When periodically switching the operating states of the tunable components integrated into the metasurface, the higher order harmonics can be generated in a nonlinear way for the RCS reduction [26][27][28][29][30]. However, the reported spatial and temporal coding schemes are only employed for the scattering wave manipulation.…”