Honeycomb 3-D Multi-angle Retrodirective Metasurface

A novel technique for designing a 3-D multi-angle retrodirective metasurface (3D-MRDM) is proposed. Firstly, based on Floquet theory and the surface impedance theory, the surface current required for accurate retroreflection of the multi-angle retrodirective metasurface (MRDM) is deduced. Secondly, subcells of the MRDM are refined according to the surface current so that the MRDM can achieve high-efficiency retroreflection of multiple angles in the two-dimensional plane. The MRDM is finally extended to a 3D-MRDM by a specially designed honeycomb-meta (HM). A 3D-MRDM that can simultaneously achieve the efficient retroreflection of a TE polarized wave incident at seven angles on all three primary channels at every 120° azimuthal interval is designed as a conceptual example. Due to the unique configuration of the HM, the seven incident angles still have high retrodirectivity when the azimuth of the incident wave deviates from the three primary channels by ±5°. The measured results verify that the 3D-MRDM enables the retroreflection of seven incident angles simultaneously over an azimuthal range up to 30°. The design approach offers new perspectives for expanding the MRDM’s angular domain, opening up opportu-nities for its application in radar electronic warfare as calibration targets or mounted on target drones.