Experimental Validation of an Active Parallel-Plate-Waveguide-Loaded Metasurfaces Lens for Wide-Angle Beam Steering

Layer-stacked metasurfaces or frequency selective surfaces have been employed as a cost-effective approach to design reconfigurable lenses. Previous work showed that the intrinsic technical drawback, i.e., the transverse field interaction effect, significantly limits the beamforming performance of these electrically thick lenses. In this letter, an active metasurface lens loaded with parallel-plate waveguide (PPW) is experimentally validated. By inserting PPW into electrically thick lenses, the transversely propagating field inside the lenses can be completely blocked, based on which the beam-steering range and the sidelobe level (SLL) can be remarkably improved. A linear PPW lens array operating around 5.75 GHz is fabricated. Experimental results show that the scanning coverage of lens antenna can reach ±60°, and the SLL are below −15.7 dB within ±50°.