Submm-wave planar focusing devices based on holographic reflectarrays

A new type of reflectarrays designed for simple and sophisticated focusing of submillimeter-wave radiation is proposed and experimentally investigated at the wavelength of 0.86 mm. The reflectarrays are implemented as single-layer grounded-slab-backed metasurfaces with a computer-generated spatial distribution of the reflection phase. The 360-degree phase alteration is achieved via topological morphing of the metasurface pattern from metallic patches to U-shaped and split-ring resonator elements, whose spectral response is derived from full-wave electromagnetic simulations. The proposed approach demonstrates the high-performance solution for creating purely flat, low-cost and light-weight beam-shaping and beam-focusing devices for mm-, submm-, and THz bands.