Reconfigurable Intelligent Surfaces (RIS): smart reflectors

RIS Operating Principles

A Reconfigurable Intelligent Surface is a planar metasurface composed of numerous low-cost passive elements, each capable of independently adjusting the phase and amplitude of incident electromagnetic waves. By dynamically programming these elements through a controller, RIS can steer reflected signals toward intended receivers, creating virtual line-of-sight paths in non-line-of-sight environments. Unlike traditional relays, RIS elements are passive — they reflect rather than amplify, consuming minimal energy. A typical RIS panel may contain hundreds to thousands of elements operating across…