Liquid crystal tunable metasurface

The invention discloses a liquid crystal tunable metasurface, belongs to the technical field of microwave device engineering, and aims to solve the technical problems of low tuning rate, large structural unit size and poor out-of-band rejection of a conventional liquid crystal tunable metasurface. The metasurface is formed by regularly arranging structural units, and each structural unit is composed of a top dielectric plate, an upper metal structural layer, a liquid crystal layer, a lower metal structural layer and a bottom dielectric plate which are sequentially stacked from top to bottom. The lower metal structure layer is composed of a first rectangular metal patch, a second rectangular metal patch, a right-angle U-shaped strip-shaped metal patch and a protrusion, the protrusion is arranged at one rectangular edge of the first rectangular metal patch and one rectangular edge of the second rectangular metal patch, the rectangular edges form two U-shaped side walls of the right-angle U-shaped metal patch, a