RIS-Aided Polarization Aware Optimal WPT

This paper characterizes the impact of polarization on sustainable wireless power transfer (WPT) to the mobile Internet-of-Thing (IoT) devices, focusing on various transmitter and receiver antenna polarization states. It investigates both line-of-sight (LOS) and controlled non-LOS (NLOS) reflections via reconfigurable intelligent surface (RIS), deriving closed-form expressions for received power to identify optimal antenna polarization. Theoretical findings are experimentally validated in an anechoic chamber, showing strong agreement with a normalized root mean square error <= 0.08. The research also assesses the necessity of RIS's polarization handling, concluding its non-essentiality in single source-receiver setups. Simulations reveal that horizontal polarization boosts received power by >= 28% compared to other polarizations. Furthermore, incorporating RIS in green communication significantly enhances received power.