Investigating Sparse Reconfigurable Intelligent Surfaces (SRIS) via Maximum Power Transfer Efficiency Method Based on Convex Relaxation. - Hans-Dieter Lang; Michel A. Nyffenegger; Heinz Mathis; Xingqi Zhang (CoRR, 2023)

Reducing Simulation Effort for RIS Optimization using an Efficient Far-Field Approximation. - Hans-Dieter Lang; Michel A. Nyffenegger; Heinz Mathis; Xingqi Zhang (CoRR, 2025)