Reconfigurable Coding Metasurface for Dual-band Dynamic Near-field Microwave Focusing

We propose a dual-band coding metasurface capable of manipulating the near-filed behaviors of electromagnetic (EM) waves independently in two discrete frequency bands. As a proof of concept, we show that the programmable coding metasurface can focus the incidence into spots with distinct focal distances at two operating frequencies. Full-wave simulations are performed to validate the design principle and the dynamic focusing functionality. The proposed metasurface may be utilized to improve the information capacities, which may have potential applications in radar and wireless communication systems.