Frequency Selective Reflection of Wideband Signals with Reconfigurable Intelligent Surfaces

Recently, the reconfigurable intelligent surface (RIS) technology has ushered in the prospect of control over the wireless propagation environment. By establishing alternative propagation paths for the transmitted signals, and by reflecting them in a controllable manner, the RIS is able to improve the signal reception. However, an aspect often overlooked is the potential bandwidth restrictions on the wideband signal reflected by the RIS. If not carefully considered, this can become an impediment for the adoption of the RIS in the next generation of communications systems. Therefore, in this work we propose a RIS configuration method that provides frequency selective signal reflection for wideband signals.