Modulation of electromagnetic waves by transparent gradient metasurfaces

Abstract

This paper illustrates the modulation capability of the metasurface (MS) for the impinging electromagnetic (EM) waves. The metasurface introduces abrupt phase change to the incident EM waves and thus provides flexibility for the out-going beam directions. As a proof of concept, two gradient metasurfaces are designed and simulated. The two metasurfaces are comprised of three and ten number of unit cells (UCs) respectively. The first MS with three UCs introduces high phase gradient in the direction of E-field and causes high deflection to incoming EM waves. In contrast, the second MS with ten UCs, provides low phase gradient which is attributed to less deflection but better side lobe level (SLL). The qualitative analysis of both designs is shown and results are validated through Fermat's principle.