Multi-beam reconfigurable intelligent surface with adaptive power allocation for multi-user communication

This work presents a multi-beam reconfigurableintelligent surface (RIS) capable of adaptive power allocationfor multi-user wireless communication systems. Unlikeconventional RIS configurations that generate beams with fixedamplitudes, the proposed design can dynamically adjust thepower levels of individual beams depending on the requirementsof users located at different spatial positions. The concept isvalidated for both single-user and multi-user scenarios byimplementing RIS structures with different phase quantizationlevels (1-bit, 2-bit, and 3-bit). For the multi-beam case, twobeams are formed toward arbitrary target directions at (θ₁, φ₁)= (30°, 45°) and (θ₂, φ₂) = (30°, 135°), and their power ratios areindependently controlled to realize both equal and unequalpower allocation schemes. The simulation results demonstratethat the proposed RIS architecture enables flexible multi-beamsteering with tunable power distribution, thereby offeringstrong potential for next-generation multi-user MIMO and RISassisted wireless networks.