Self-Phased Metasurface Pixels/Cells: Concept, Design and Applications

Metasurfaces can be categorized into two types, i.e., transmission-type and reflection-type. In general, they allow electromagnetic waves either to be transmitted or reflected with the manipulation in phase and or amplitude. The transmission/reflection phase can also be tuned by incorporating active circuit elements into the metasurface pixels/cells' design. This paper presents a self-phased metasurface pixel/cell concept that mainly focuses on the tunability in both the transmission and reflection phase without using lossy active circuit elements. The tunable phase can be realized by using constituent material as the substrate supporting the metasurface. In transmission-type, we propose a unit cell design that consists of three layers of a metallic ring surrounding a metallic patch; all are integrated into a constituent material used as substrates. In reflection-type, the presented pixel/cell design consists of a dual-circular ring, incorporating a meandered slot line, or an interdigitated line, in between. All are also integrated on a dielectric layer with a metal backing used as a constituent material. Simulation results show that the designed unit cells can achieve over 220 degrees of tunable phase with an insertion loss of less than 3 dB in the transmission configuration and 220 degrees of tunable phase with less than 2 dB loss in the reflection configuration. The proposed concept is implemented to design the reconfigurable transmit and reflectarray without lossy phase shifters or active circuit elements.