A New Paradigm for Reconfigurable Intelligent Surface Design: Multiport Network Method

Abstract

As a novel approach to flexibly adjust the wireless environment, reconfigurable intelligent surfaces (RISs) have shown significant application potential across various domains, including wireless communication, radar detection, and the Internet of Things. Currently, mainstream design methods for RISs face inherent limitations. For instance, while the full-wave electromagnetic (EM) simulation method offers strong universality, it suffers from low efficiency. Machine-learning-based methods can effectively reduce design time but are heavily dependent on full-wave EM simulations. Although the design methods based on the equivalent circuit can lessen the reliance on full-wave EM simulations, they still struggle with insufficient model accuracy when dealing with complex element structures. In recent years, a new multiport network method has been introduced to RIS design. This method has significantly enhanced the accuracy of modeling complex structures. It reduces the dependency on full-wave EM simulations and substantially shortens the design time. This work provides a detailed exploration of the RIS element design strategy based on multiport network and discusses future development trends in this field.