RCS reduction based on double parabolic phased metasurface

This paper presents a novel metasurface design strategy to realize broadband radar cross section (RCS) reduction. The phase distribution across the metasurface aperture can be regarded as applying an additional parabolic phase upon periodically arranged parabolic subarrays. Such a design fully utilizes the diffusive scattering nature of the parabolic phase distribution. Since the proposed metasurface is governed by only two focal lengths, the optimization procedure is quite easy compared to metasurface with random coding sequence. Experimental results show that the proposed metasurface can achieve more than 10 dB RCS reduction from 7.52 GHz to 19.66 GHz with a fractional bandwidth of 89.3% under both linearly and circularly polarized normal incidences, and keeping a performance of more than 7 dB RCS reduction until the incident angle increases to 40 & DEG; for both x-polarized and y-polarized incidences in the frequency range of 8-19.35 GHz. When the incident angle increases to 60 & DEG;, 7 dB RCS reduction can still be obtained for x-polarized incidence from 7.9 GHz to 19.35 GHz with a fractional bandwidth of 84%.