RIS Development and Implementation in a mm-Waves 5G-NR System Toward 6G

This letter reports a reconfigurable intelligent surface (RIS) design, development and implementation in a millimeter-waves 5G-NR indoor system operating at 24.5 GHz. The proposed RIS is composed of 1024 elements controlled by varactor diodes in a column-wise fashion for producing linear phase gradients. Beam steering based on reflection patterns from 30° to 60° is experimentally demonstrated. Moreover, an indoor experiment is reported using a 64-QAM 5G NR signal at 24.5 GHz with bandwidth of up to 400 MHz, achieving a maximum throughput of 1.2 Gbit/s. The RIS deployment results in a channel power and signal-to-noise ratio (SNR) improvement of 21.5 and 23.8 dB, respectively, implying a significant enhancement of the measured root mean square error vector magnitude (EVMRMS) from 92.23 to 6.12% that underscores the impact of the RIS beam steering function at the targeted angle.