Reconfigurable Intelligent Surfaces: Field Trial Campaign for Performance Evaluation from Near- to Far-Field Regions

Future communication systems are expected to employ Reconfigurable intelligent surfaces (RIS) for real-time manipulation of channel to achieve unprecedented efficiency and quality of service (QoS) improvement. Here, we have designed a practical RIS-enabled communication setup to demonstrate beam steering and multi-beam forming in near- to far-field trials. The design of RIS as a component of wireless communication system has many variables that dictate path loss compensation capability of RIS. We investigate RIS path loss compensation by varying RIS size with point source and plane wave source using a 1bit RIS of size 27 x 28 unit-cells. It is observed that RIS size has less significance compared to phase quantization, in the near field while the effect of RIS size is dominant in the far field. The reported results provide useful insights for design of RIS-enabled wireless communication systems.