All-Dielectric Fabry–Pérot-Based Compound Huygens’ Structure for Millimeter-Wave Beamforming

Novel Fabry-Pérot resonator-based compound Huygens' structure with two all-dielectric metasurface layers is proposed and experimentally demonstrated. This design consists of two dielectric layers with about a quarter-wavelength separation at the center frequency. Each layer is a 2-D lattice of dielectric resonators. To realize the structure mechanically, each dielectric resonator is connected with its neighboring resonators using four interconnections or “two bridges.” The two bridges allow for a mechanically strong design with low fabrication tolerances. The two layers are used to cancel the reflections from the bridges, and hence achieve low backscattering in a wide bandwidth. Full-wave simulations are used to realize various beam transformations in the millimeter-wave (mm-wave) band, such as refracted and difference-pattern (DP) beams. The proposed structure is also successfully demonstrated using experiments for the uniform and DP beams at the mm-waves.