Rigorous Susceptibility-Based Design of Generalized Huygens' Metasurface Radomes

In this paper, we utilize the profound generalized Huygens' condition (GHC) to rigorously devise all-angle transparent metasurface (MS) radomes. We extend our recent configuration of double-layered admittance-sheet cascades, which allows only one Huygens' condition to hold (at grazing angle), by incorporating a third middle layer; we thus fully satisfy Huygens' condition both at normal and grazing angles in closed form. Our meticulous analysis introduces a universal nonlocal link between macroscopic MS constituents and their corresponding effective meta-atom susceptibilities. Particularly, it reveals that the trilayered composite inevitably manifests effective normal susceptibilities overlooked by common tangentially-polarized MS design practices. A printed-circuit-board version of the radome is realized and inspected in theory and simulation. Its excellent observed performance validates the GHC in a fundamental practical situation and sets the stage to cutting-edge performance in advanced nonlocal wave-moulding functionalities.