Metasurface Antenna Array for Flat-Top Beam Formation and Low Radar Cross-Section

This paper presents a metasurface antenna array that combines flat-top beam formation with low radar cross-section (RCS) characteristics. The proposed polarization conversion metasurface (PCM) achieves a remarkable reduction of more than 8 dB in RCS across the frequency range from 13.1 GHz to 35.9 GHz. By integrating the PCM with a reference antenna array, a low-RCS antenna array is formed. Both the reference antenna and the low-RCS antenna exhibit a resonance frequency of 3.4 GHz, with a reflection coefficient significantly lower than -10 dB. The isolation degree between the elements of the low-RCS antenna array is fewer than -15 dB. Furthermore, the low-RCS antenna array not only achieves RCS reduction across an ultra-wideband coverage bandwidth but also enables complex beamforming, such as the flat-top beam.