Reconfigurable Metasurface Reflectors Using Split-Ring Resonators With Co-Designed Biasing for Magnitude/Phase Control
Mohamed K. Emara, Debidas Kundu, Keigan MacDonell, Leandro Rufail, Shulabh Gupta
Abstract
A novel reconfigurable metasurface reflector with a simple architecture is proposed based on either p-i-n or varactor diodes for magnitude and phase control, respectively. Each metasurface reflector is based on a single-dielectric two-metal-layer printed-circuit board (PCB), with a tunable resonator on the top metal layer and biasing on the bottom metal layer. The metasurface reflectors are designed for reconfigurability on a column-by-column basis (i.e., single-plane beamforming). Biasing is integrated in the design of the unit cell and RF-dc isolation is implemented at the ends of each reflector column. The bias lines are designed to have minimal effect on the resonator characteristics, while appropriate architectures are devised for each configuration involving p-i-n or varactor diodes. To demonstrate various functionalities of the metasurfaces, the p-i-n-based metasurface reflector is used to demonstrate magnitude control, sidelobe level control, and binary amplitude grating to generate three symmetrical beams. The varactor-based metasurface reflector is used to demonstrate single beam-steering and binary phase grating to generate two symmetrical beams.