An accurate and simple analytical model for the computation of the reflection
amplitude and phase of Reconfigurable Intelligent Surfaces is presented. The
model is based on a transmission-line circuit representation of the RIS which
takes into account the physics behind the structure including the effect of all
relevant geometrical and electrical parameters. The proposed representation of
the RIS allows to take into account the effect of incidence angle, mutual
coupling among elements and the effect of the interaction of the periodic
surface with the RIS ground plane. It is shown that the proposed approach
allows to design a physically realisable RIS without recurring to onerous
electromagnetic simulations. The proposed model aims at filling the gap between
RIS assisted communications algorithms and physical implementation issues which
determine realistic performance of these surfaces.

本研究提出了一种基于传输线电路表示的可重构智能反射面（RIS）的反射幅度和相位计算的准确简单分析模型，该模型考虑了结构背后的物理学，包括所有相关的几何和电气参数的影响，可以设计出一个无需使用昂贵的电磁模拟即可实现的 RIS。该模型填补了 RIS 辅助通信算法和物理实现问题之间的差距，有助于确定这些表面的实际性能。