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

Abstract

This paper presents a spatiotemporal encoding metasurface design to independently achieve the good radiation and the low scattering performances in the same frequency band. The proposed metasurface unit cell is composed of a square patch and two orthogonally placed I-shaped strips. By switching the operating states of the PIN diode inserted into each I-shaped strip between ON state and OFF state, a phase difference of 180° can be obtained in the band of 7.6–7.95 GHz for two orthogonally polarized incident waves. When a coaxial probe is introduced at the diagonal line of the square patch, the dual-polarized radiation capability is achieved within the frequency range of 7.6–7.95 GHz. With the proposed metasurface unit cell, the manipulation of the radiating wave and the scattering wave has no influence on each other. By controlling the PIN operating states by the field programmable gate array in real time, the power of the scattering wave is transferred to some higher order harmonics, thus realizing radar cross section (RCS) reduction. With optimized spatial and temporal encoding layouts, the proposed metasurface realizes the RCS reduction over 10 dB within the range of 7.3–8 GHz, with the maximum RCS reduction of 35.6 dB, while maintaining good radiation capability.