RCS Reduction via Coding Metasurfaces with Pancharatnam-Berry Phase Modulation

In this paper, two types of coding metasurfaces are designed based on the rotational phase modulation of the unit cell to reduce the radar cross section (RCS). The polarization conversion rate (PCR) of the unit cell exceeds 93.4% within the frequency band of 12.1-25.4 GHz. The 1-bit coding metasurface consists of two elements, denoted as "0" and "1", with rotational angles of ±45 degrees, respectively. By employing a rotation angle interval of 22.5° per element and a range spanning from 0° to 157.5°, a 3-bit coding scheme is realized, enabling the formation of a 3-bit coding metasurface. Both the 1-bit and 3-bit coding metasurfaces comprise 40×40 units cell, resulting in a total size of 200mm×200mm. Compared to the equivalently sized copper plates, the proposed metasurfaces yield 10dB RCS reduction within the 12.2-25.3 GHz frequency range. The simulation results validate that the design methodology of metasurfaces is effective, showcasing significant potential for applications in emerging technologies and materials for stealth capabilities.