Polarization-controlled coding metasurface with phase cancellation and diffusion for enhanced radar cross section reduction

A novel metasurface design is presented integrating polarization conversion, diffusion, and phase cancellation mechanisms for broadband radar cross-section (RCS) reduction. The metasurface employs a rotationally symmetric configuration, enabling efficient dispersion of electromagnetic waves in x and y polarizations. By changing the unit cell size, polarization conversion optimization is accomplished. This results in a 180[Formula: see text] phase difference for the 1-bit design and 22.5[Formula: see text] for the 2-bit design, with reflection magnitudes surpassing 0.9 in the 11.2-20.2 GHz and 12.3-19.5 GHz frequency ranges, respectively. The genetic algorithm (GA) was employed to optimize the arrangement of unit cells, identifying the most effective configuration for scattering and RCS suppression. Simulation results under LP normal incidence demonstrate significant RCS reduction capabilities. The 1-bit metasurface achieves approximately 10 dB RCS reduction across 12.3-19.2 GHz, corresponding to a relative bandwidth of 43.81%. In contrast, the 2-bit metasurface achieves a 20 dB decrease inside 12-19.3 GHz (relative bandwidth 46.65%) and a wider 10 dB reduction over 11.1-20.3 GHz (relative bandwidth 58.60%), with a peak reduction of roughly 15 dB in the 13.5-15.4 GHz range. Additionally, co-polarized reflections produced by the Pancharatnam-Berry (PB) phase or unit cell rotation introduce continuous phase discrepancies, which aid in efficient wave manipulation. Under LP oblique incidence, the metasurface demonstrates robust performance. Over 12.3-18.9 GHz, the 1-bit design retains RCS reduction of 10 dB up to a 15[Formula: see text] incidence angle (relative bandwidth 42.3%), while the 2-bit design extends this capability up to a 30[Formula: see text] incidence angle across 12-19.3 GHz (relative bandwidth 46.65%). Both simulated and experimental results validate the metasurface's ability to manipulate electromagnetic waves and achieve effective RCS reduction, highlighting its potential for advanced stealth and electromagnetic wave control applications.