A Power-Balance Model for Quantized mm-Wave RIS: Concept and Experimental Assessment

Reconfigurable Intelligent Surfaces (RIS) are emerging as low-cost, energy-efficient solutions to control wireless propagation. Practical RIS reconfigurability is achieved through phase quantization, e.g. using 1-bit PIN diodes, which may lead to anomalous reradiation modes, limiting the signal coverage enhancement towards the intended direction. Such quantization modes should be taken into account to tune realistic RIS models through proper, physically sound parameters. The goal of this work is to design and evaluate a power balance model for reflective RIS, explicitly accounting for both quantization-induced and parasitic reradiation modes alongside desired reradiated power. We parametrize the model by performing signal measurements in a realistic scenario, using a 1-bit RIS operating at mm-Wave frequencies. The proposed approach analyses how phase quantization redistributes power across modes and provide a framework for realistic RIS modeling.