Ultra-broadband microwave metasurfaces for polarizer and beam splitting

Abstract

Realization of ultra-broadband transmission-type functional metasurfaces is of high priority for the development of modern electromagnetic systems. In this paper, we propose a new strategy to design highly efficient ultra-broadband microwave metasurfaces with ultra-thin profiles that enable linear polarization and asymmetric transmission by merging two differently sized meta-atoms operating in neighbour frequency bands into a meta-molecule featuring an extended bandwidth. Capitalizing on the meta-molecule approach, we realize a transmission-type beam splitter based on the coding concept, which can, at higher frequencies, divide a normally incident wave into two beams propagating along symmetrical oblique directions and, at lower frequencies, couple the incident wave into two surface waves propagating away from the splitter in opposite directions. Our findings demonstrate thereby a flexible and robust approach for the realization of efficient ultra-broadband transmission-type metasurfaces that can readily be integrated into complex systems in order to implement multiple functionalities in microwave communication networks for diverse applications.