Integrated Low RCS Circularly Polarized Antenna Based on Multimode Metasurface

In this letter, an integrated low radar cross section (RCS) circularly polarized (CP) antenna based on multimode metasurface is proposed. The mode resources of the metasurface are fully utilized, and each mode are endowed with various functions by different excitation methods. As a result, the stealth and radiation properties are integrated into a simple structure. A specific design is carefully elaborated to illustrate this route. First, a rectangular patch is diagonally placed to perform wideband polarization rotation, which has three distinct resonant modes. Next, the polarization rotation of the middle mode is destroyed by central slotting, which is utilized as the antenna's operating mode. Finally, proper feeding techniques are used to excite the middle mode to produce a efficient radiation. As an example, an 8 × 8 metasurface-based integrated low RCS CP antenna array is designed and fabricated, which achieves both reliable radiation performance and effective RCS reduction simultaneously. Both simulated and measured results verify the effectiveness of the proposed method.