Broadband RCS Reduction Based on Spiral-Coded Metasurface

Abstract

In this letter, an efficient approach for broadband radar cross-section (RCS) reduction is proposed. By coding eight types of linear-phase gradients in a spiral pattern, the reflected wave was uniformly diffused, and thus, the backscatter RCS reduction was achieved within an ultrabroadband. For verification, a spiral-coded metasurface composed of $8\times 8$ subarrays is designed, fabricated, and measured. Numerical and experimental results both show that the thin metasurface enables a 10 dB RCS reduction over an ultrabroadband ranging from 12.2 to 23.4 GHz. Moreover, the good merit of our approach is further demonstrated by comparing the scattering behavior to the steering beam of a regular sequential layout pattern. Our approach features broad band, polarization insensitivity, wide incident angles, and easy design without any optimization, promising great potential in real-world low-scattering stealth applications.