An ultrawideband stacked metasurface with collaborative polarization conversion and absorption characteristic for application of radar cross section reduction

Abstract

In this paper, an ultrawideband metasurface with collaborative polarization conversion (PC) and absorption characteristic has been designed and applied into radar cross section (RCS) reduction. The unit cell of the proposed metasurface is a stacked structure composed of top-layer low-frequency PC-absorption (PCA) unit cell, the bottom-layer high-frequency PC unit cell, and metallic ground. Some lumped resistors are used in the low-frequency PCA unit cell to simultaneously improve the high-frequency transmission and low-frequency PCA performance. With orthogonal layout of two kinds of the unit cells, the parasitic Fano resonance can be avoided, and meanwhile the two operating bands are cascaded together to achieve an ultra-wide band with a frequency-ratio (FR) of 7.26 from 2.7 GHz to 19.6 GHz. The proposed metasurface is arranged into an array in a checkerboard way to obtain a low-RCS performance. The simulated and measured results are given to demonstrate a 10 dB RCS reduction in an ultrawideband of 2.85–18.65 GHz with a fractional bandwidth (FBW) of 146.98%.