Optically Transparent Reflectarray Based on Integrated Ferroelectric Devices for Real-Time Phase Control

A novel optically transparent active reflectarray metasurface is proposed in the 5G mmWave band of 28 GHz based on specially designed varactor diodes using barium strontium titanate (BST) thin films for phase control applications. By varying the voltage bias of the BST thin film, the dielectric constant and hence capacitance can be changed thus allowing phase response manipulation. Simultaneously, the proposed design consists of a perforated honeycomb mesh as a ground plane on a fused silica substrate for achieving a high degree of optical transparency. This paper shows the potential for ferroelectric materials to be used as varactor diodes for beamsteering metasurface applications in the 5G mmWave regime using full-wave simulations.