Design of Ultra-Wideband Low RCS Antenna Based on Polarization Conversion Metasurface

An ultra-wideband and radar cross-section (RCS) antenna array based on polarization conversion metasurface (PCM) is proposed. Firstly, the PCM unit is proposed, and its performance is analyzed. In terms of radiation performance, the −10 dB impedance matching bandwidth of the PCM unit is 8.5–30.2 GHz (a relative bandwidth of 112.1%) and the polarization conversion ratio (PCR) is higher than 90%. In terms of scattering performance, the antenna achieves more than 10 dB RCS reduction in the band of 8.35–30.45 GHz (a relative bandwidth of 113.9%). Secondly, the PCM unit is combined with the microstrip antenna, and its performance is analyzed: the gain of the microstrip antenna is increased by 2.8 dB at 19.5 GHz compared to the antenna without the PCM, and the low-RCS antenna array achieves RCS reduction over 6 dB within the frequency range of 8.3–31.7 GHz (a relative bandwidth of 117%). The antenna array has the advantages of wide bandwidth, high gain, and low RCS. It can be used for radars, aircraft, and stealth platforms.