6G • RAN
Active RIS (Amplifying Metasurface)
Reconfigurable Intelligent Surface with Integrated Micro-RF Amplifiers
Metasurface equipped with integrated low-noise amplifiers that actively boosts weak reflected signals to overcome severe double-fading path loss.
Technical Explanation
Passive RIS suffers from 'double path loss' (the product of transmitter-to-RIS and RIS-to-receiver distances), which severely diminishes received power at high frequencies. Active RIS integrates low-power tunnel diodes or transistor amplifiers into each meta-atom unit cell. By amplifying the reflected or transmitted waves by 15-25 dB while consuming only a few watts, it overcomes double-fading and dramatically extends 6G sub-THz and FR3 coverage in non-line-of-sight zones.
Key Functions
- Amplifies incident radio beams by 15-25 dB using low-power integrated amplifiers
- Overcomes multiplicative double path loss inherent in passive reflecting surfaces
- Suppresses thermal noise amplification through optimized element reflection gains
- Extends high-speed coverage into deep indoor basements and architectural dead zones
Specifications
IEEE Wireless Communications Letters, 3GPP Rel-19 Smart Surfaces
Interfaces
Active RIS Bias ControllerRF Power SupplyRIC Control Plane
Related 6G Concepts
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