A novel 24GHz lens antenna based on phase gradient metasurface

Abstract

This paper proposes a novel 24 GHz lens antenna based on phase gradient metasurface. The metasurface unit cell has three dielectric substrate layers separated by air, each of which is etched with the same metal structure on both sides. Unit cell analysis indicates that good linearity and complete coverage of the transmission phase can be achieved. An metasurface with 11×11 units is designed based on the proposed unit cell, which can effectively focus the plane wave and accompanies a simple patch antenna as the feed to illuminate the metasurface. The simulation results show that the maximum gain of the lens antenna is 22.4dBi(an increase of 14.3dBi). The 1dB gain bandwidth is 4.13%(1.08GHz), the E-side sidelobe level is -21dB, the front-to-back ratio is 20.9 dB, the H-side sidelobe level is -19.5 dB, and the front-to-back ratio is 19.2 dB, which basically meets the application index of 24 GHz millimeter wave radar.