Ultra-Broadband Stealth Vortex Wave Antenna Based on Metasurface

Vortex wave can be applied in the domain of wireless communication technology to improve spectrum utilization and communication capacity. However, the current generation method of vortex wave is defective, especially the design of vortex wave antenna with broadband and low RCS still faces great challenges. In this paper, an ultra-broadband stealth vortex wave antenna is proposed based on metasurface (MS). After y-polarized spherical wave passes through the MS, the MS converts y-polarized spherical wave into x-polarized vortex wave at front side. When y-polarized wave illuminates the MS from back side, the antenna array scatters y-polarized reflected wave to realize diffuse scattering function and reduce the backward RCS of the antenna system. By exciting the MS with horn antenna, a stealth vortex wave broadband antenna system is realized. The broadband antenna system has both high gain vortex wave radiation performance and low backward RCS scattering performance in the same frequency spectrum simultaneously. The experimental results show that the 3 dB gain relative bandwidth of the stealth vortex EM wave antenna is 58% (11 GHz~20 GHz). Besides, the RCS of the antenna system can be reduced more than 10 dB between 11.3 GHz to 20 GHz (relative bandwidth is 56%).