Research on RIS-Based Full-Duplex Interference Cancellation Techniques with Experimental System

To address the issue of strong self-interference in fullduplex technique, a RIS-based experimental system is designed and implemented. This system includes transceiver antennas, RIS and its control circuitry, as well as the control and optimization algorithm. Experimental results show that, without RIS, the S21 parameter of the transceiver antennas is $\mathrm{- 2 5} \mathrm{~ d B}$ at 6.75 GHz. In contrast, under the optimal RIS state, the S21 parameter of the transceiver antennas is below - $\mathrm{4 0} \mathrm{~ d B}$ within the frequency band of 6.73 GHz to 6.75 GHz, and at the frequency point of 6.74 GHz, the S21 parameter reaches $\mathrm{- 5 9} \mathrm{dB}$. This significant improvement demonstrates an obvious enhancement in the operational performance of full-duplex mode.