6G • RAN
BD-RIS
Beyond-Diagonal Reconfigurable Intelligent Surface
A generalized metasurface architecture with inter-element reconfigurable impedance networks enabling arbitrary wave scattering and multi-beam generation.
Technical Explanation
Conventional RIS implementations assume a diagonal phase-shift matrix where each antenna element operates in complete isolation. Beyond-Diagonal RIS (BD-RIS) introduces reconfigurable interconnecting impedance networks between adjacent elements. By allowing electromagnetic energy to couple across elements, BD-RIS synthesizes full non-diagonal scattering matrices, delivering higher beamforming gains, wider angular coverage, and flexible group-connected multi-user multiplexing with significantly fewer elements.
Key Functions
- Non-diagonal scattering matrix synthesis with cross-element impedance coupling
- Significantly higher beamforming gain compared to traditional diagonal RIS architectures
- Flexible multi-beam generation and wide-angle wave redirection
- Reduced hardware component count for equivalent spatial beam resolution
- Optimized for polarization conversion and anomalous wave steering in Sub-THz bands
Specifications
IEEE Transactions on Communications, ETSI ISG RIS Technical Report
Interfaces
BD-RIS-CtrlScatter-Matrix-IF
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