A Zoom Microwave Metalens With Mechanical Rotation

A microwave metalens, consisting of two circular metasurfaces, is proposed to achieve zoom functionality through mechanical rotation. The phase distribution across different regions on each metasurface follows an arithmetic sequence along the angular direction. Upon rotating one of the metasurfaces, the overall phase distribution on the metalens changes accordingly to meet the requirements of different focal lengths. The metalens operates at 15 GHz with a radius of 80 mm. At rotation angles of 0°, 45°, and 90°, the expected focal lengths are 20, 60, and 100, respectively. The simulated electric field intensity at these focal points is 4.8, 5.6, and 4.0 V/m, respectively. Experimental results align closely with simulation outcomes. Due to its straightforward implementation principle, the proposed method holds promise for application in near-field focusing scenarios.