Reconfigurable intelligent surface design in phase-space

Reconfigurable intelligent surfaces are planar structures that dynamically change their reflection or refraction behaviour to engineer complex propagation environments. A physics-based modelling framework is formulated that accounts for the scattered electromagnetic field by an array of reconfigurable unit cells. The model is grounded on finite-size electric/magnetic surface current densities, and develops a wave-dynamical phase space, or angular-positional, representation of scattered waves. The phase-space representation facilitates the integration of intelligent surfaces within Eulerian ray-tracing methods, such as the Dynamical Energy Analysis. The framework is used for evaluating and optimising the design of beam-splitters and anomalous reflectors. A Wigner transform approach is used to devise the field-based phase-space representation. Obtained results are the first step towards the development of a flexible and efficient coverage planning tool for multi-RIS mobile networks.