What RIS technology actually does — and why it matters for 6G
A Reconfigurable Intelligent Surface (RIS) is a planar array of sub-wavelength, individually controllable electromagnetic unit cells — realized as programmable metasurfaces — that alter the phase, amplitude, frequency, and polarization of incident radio waves without requiring conventional active RF transceiver chains. The core operating principle is passive or near-passive beamforming: reflecting elements apply controlled phase shifts to steer energy toward intended receivers, create virtual line-of-sight paths, suppress interference, or concentrate power for wireless charging.
The significance of this architecture lies in what it replaces. Conventional wireless networks treat the propagation environment — buildings, vehicles, atmospheric conditions — as an obstacle to be overcome by increasing transmit power or deploying more base stations. RIS inverts this logic entirely: the environment itself becomes a configurable resource. According to research published by WIPO-tracked institutions across Europe and Asia, this shift promises step-change gains in coverage, spectral efficiency, energy efficiency, and integrated sensing simultaneously.
The technology is referred to interchangeably across the dataset as RIS, Intelligent Reflecting Surface (IRS), Large Intelligent Surface (LIS), Reconfigurable Smart Surface (RSS), and Holographic MIMO Surface (HMIMOS) — reflecting an evolving and as-yet-unstandardized nomenclature. This terminological fragmentation is itself a signal: the field has not yet coalesced around a single standard, which means the IP landscape remains open and contested.
Within this patent and literature dataset, the same underlying technology — programmable metasurface arrays for wireless channel control — is described using at least five distinct terms. RIS (Reconfigurable Intelligent Surface) is the most widely adopted in recent filings, but IP searches must cover all variants to achieve complete landscape coverage.
Lund University articulated the foundational concept of a Large Intelligent Surface as a contiguous electromagnetically active receiving structure surpassing massive MIMO as early as 2018. Institut Langevin and ESPCI Paris published the landmark framing of RIS for 6G wireless communications in 2019 — establishing the conceptual vocabulary that all subsequent work builds upon. In the seven years since, the field has moved from theoretical framing through hardware prototyping and is now entering the standardization phase, as evidenced by Qualcomm’s 2025 air interface patents.
Reconfigurable Intelligent Surface (RIS) technology uses planar arrays of sub-wavelength, individually controllable electromagnetic unit cells to alter the phase, amplitude, frequency, and polarization of incident radio waves without conventional active RF transceiver chains, enabling passive or near-passive beamforming for 6G wireless networks.
From concept to prototype: the RIS innovation timeline 2018–2026
The RIS innovation trajectory follows a clear four-phase arc — from foundational concept (2018–2019) through theory consolidation (2020–2021), hardware validation (2022), and into commercial standardization (2023–2026). Each phase has distinct characteristics in terms of institution type, publication format, and geographic origin.
The 2020–2021 period is notable for its myth-busting character. Linköping University explicitly debunked three widespread myths about RIS in 2020, including exaggerated pathloss and array gain claims — a signal that the field was mature enough to self-correct. Laboratoire des Signaux et Systèmes (L2S, France) produced multiple papers addressing overhead-aware resource allocation, optimal element count, and holographic MIMO surfaces, establishing the analytical frameworks still in use today. ShanghaiTech University (2021) identified the three foundational physical-layer challenges — channel estimation, passive information transfer, and robust design — that continue to drive research.
“The most recent filings signal a transition toward commercial implementation — Qualcomm’s 2025 EP patent on RACH procedures for RIS-assisted UE access is the clearest signal in this dataset of imminent 3GPP standardization activity.”
The 2022 hardware validation phase is anchored by three landmark prototypes. Arizona State University deployed a 160-element RIS at 5.8 GHz in outdoor scenarios, measuring actual pathloss and coverage improvements. The University of Surrey designed and characterized a 2,430-unit-cell RIS at 3.5 GHz with varactor diode tuning. NEC Laboratories Europe built and tested an RF switch-based RIS prototype. These three experiments collectively shifted the evidentiary basis of the field from simulation to measurement — a necessary precondition for operator deployment planning.
In 2022, Arizona State University deployed a 160-element RIS prototype at 5.8 GHz in outdoor scenarios measuring actual pathloss and coverage improvements, while the University of Surrey characterized a 2,430-unit-cell RIS at 3.5 GHz with varactor diode tuning — collectively shifting the RIS evidence base from simulation to physical measurement.
Track the full RIS patent filing timeline and identify white-space opportunities with PatSnap Eureka’s innovation intelligence tools.
Explore RIS Patent Data in PatSnap Eureka →Four hardware architectures competing for dominance
RIS hardware is not a single technology — it is a family of competing architectures, each with distinct performance trade-offs, frequency ranges, and deployment implications. The dataset reveals four primary control modalities and a fundamental architectural fork between passive and active designs.
Control modality landscape
PIN diode switching delivers binary phase states and has been demonstrated at 28.5 GHz by ESPCI Paris/CNRS — making it the leading candidate for millimeter-wave 5G/6G deployments where high-frequency operation is essential. Varactor diode tuning provides continuous phase control and was demonstrated at 3.5 GHz by the University of Surrey, offering finer beamforming resolution at sub-6 GHz frequencies. RF switch-based patch antenna arrays, as demonstrated by NEC Laboratories Europe, offer a third path. A fourth emerging modality — liquid crystal-based RIS (LC-RIS) — is highlighted by Imperial College London as a historical bridge from liquid crystal on silicon (LCOS) technologies toward post-5G deployments.
The passive vs. active architectural fork
Beyond control modality, a more fundamental architectural decision divides the field: passive versus active RIS. Passive RIS draws power only for control circuitry, with no signal amplification — but suffers “double path-loss” in cascaded links, where the signal must travel from transmitter to surface and then from surface to receiver. Active RIS, introduced by the University of Kent, embeds amplifying reflectors to overcome this limitation. The University of Kent demonstrated that active RIS significantly outperforms passive RIS under equal power budgets in mobile edge computing offloading scenarios. However, active RIS reintroduces power consumption and noise constraints that passive designs avoid.
Neither passive nor active RIS has achieved architectural dominance as of 2026. Passive RIS suffers double path-loss in cascaded links; active RIS overcomes this but reintroduces power and noise constraints. Product developers should evaluate both architectures for their specific deployment geometry before committing to a hardware platform.
A third functional dimension — reflective, transmissive, or hybrid — is analyzed comparatively by Peking University. Purely reflective RIS serves users on the same side as the transmitter; transmissive RIS passes the signal through the surface to serve users on the opposite side; hybrid reflective-transmissive RIS serves both simultaneously. This multi-modal taxonomy is particularly relevant for building-integrated deployments, where surfaces must serve users on both sides of a wall or facade. Standards bodies including 3GPP will need to address all three functional modes as RIS integration into air interface specifications progresses.
RIS hardware architectures divide along two independent axes: control modality (PIN diode at 28.5 GHz, varactor diode at 3.5 GHz, RF switch, or liquid crystal) and amplification approach (passive RIS with no RF amplification versus active RIS with embedded amplifiers to overcome double path-loss in cascaded links).
Where RIS is being deployed: seven application domains
RIS research has diversified well beyond its initial focus on cellular coverage extension. The dataset identifies seven distinct application domains, each with its own research community, deployment geometry, and IP landscape maturity.
5G/6G cellular coverage and mmWave blockage mitigation
The largest cluster of retrieved literature addresses RIS as a coverage and capacity tool for terrestrial cellular networks, particularly for millimeter-wave bands where blockage is frequent. Politecnico di Milano developed coverage planning optimization models for mmWave networks with RIS (2021), and further studied how RIS-assisted Integrated Access and Backhaul (IAB) improves blockage resilience in dense deployments. Huawei Technologies Sweden conducted system-level simulation of RIS gains across realistic network topologies in 2023, a critical step toward operator deployment planning. According to ITU spectrum allocation frameworks, the mmWave bands targeted by RIS deployments are central to 6G capacity planning.
Non-terrestrial networks: UAV, HAPS, and LEO satellite
RIS panels mounted on UAVs, High-Altitude Platform Stations (HAPS), or Low-Earth Orbit (LEO) satellites can provide line-of-sight coverage across wide areas. Huawei Technologies Canada contributed a comprehensive integration framework for RIS with 5G/B5G aerial platforms (2021). A Korean defense agency published joint UAV placement and RIS phase optimization for aerial backhaul (2022). Istanbul Technical University extended this framework to non-terrestrial networks including interplanetary links (2022) — an indication of how broadly the community is thinking about RIS as a universal propagation control mechanism.
Intelligent transportation and autonomous vehicles
RIS deployment along highways and transportation corridors is proposed to combat high path-loss at mmWave and THz frequencies used by next-generation V2X systems. Istanbul Technical University formulated optimal RIS placement for Vehicle-to-Everything (V2X) reliability (2021). Applications for high-speed railway are specifically addressed, including Doppler shift suppression, handoff management, penetration loss mitigation, and precision train positioning — a particularly high-value use case given the density of mmWave base stations required for rail corridors.
IoT, industrial URLLC, and wireless power transfer
RIS-assisted grant-free access for uplink URLLC is proposed to improve reliability in industrial IoT scenarios by LUT University, Finland (2020). NEC Laboratories Europe’s RISMA system addresses massive IoT access over mmWave using RIS-assisted beamforming (2021). RIS-aided wireless power transfer for IoT devices — using beam scanning algorithms validated on real testbeds — is reported by Sungkyunkwan University (2022), opening a path toward battery-free sensor networks powered by ambient RF energy concentrated by RIS.
Mobile edge computing offloading
RIS is proposed as an enabler for MEC offloading by improving the quality of uplink computation offload links. Southeast University (China) proposed joint RIS-MEC optimization to enhance offloading efficiency (2021). The University of Kent demonstrated active RIS in MEC systems outperforming passive RIS (2022). Nanyang Technological University extended this to Space Information Networks, integrating RIS-assisted MEC with satellite connectivity (2021).
Localization, sensing, and positioning
RIS-assisted localization exploits the surface’s ability to create controlled multipath for angle and delay measurements. The University of Rennes analyzed radio localization and mapping with RIS (2020). Tsinghua University explored near-field RIS beamforming optimized for receivers in the Fresnel zone, enabling both sensing and communication simultaneously (2023) — a precursor to the Integrated Sensing and Communication (ISAC) functionality central to 6G specifications.
Visible light communication and LiFi
An emerging application domain applies optical-domain RIS — using mirror arrays or adjustable refractive elements — to redirect light beams in VLC systems, mitigating line-of-sight blockage. Papers from Zhengzhou (National Digital Switching System Engineering Center, 2022), the University of Victoria (distributed THz and VLC, 2023), Memorial University of Newfoundland (beam steering in VLC, 2021), and the Pontificia Universidad Católica del Ecuador (VLC with IRS, 2023) collectively form this emerging cluster. VLC and LiFi represent substantially thinner IP coverage than cellular RIS — a lower-competition entry point for organizations with the relevant photonics expertise.
Identify white-space IP opportunities across RIS application domains before standardization locks in the dominant positions.
Analyse RIS White Space with PatSnap Eureka →Geographic and assignee landscape: who holds the IP
The RIS patent and publication landscape is geographically diverse but shows clear concentration patterns. China leads in institutional research output volume; Europe leads in hardware prototyping diversity; the United States is represented primarily through Qualcomm’s commercial filings; and South Korea holds the most recent patent in this dataset.
China represents the most concentrated source of institutional research output, with major contributions from Southeast University (Nanjing), Peking University, ShanghaiTech University, Beijing Institute of Technology, Xi’an Jiaotong University, Tsinghua University, and the National Mobile Communications Research Laboratory. China Telecom’s direct commercial patent filing (CN, 2023) signals operator-level industrialization interest — a meaningful escalation from academic research to deployment-oriented IP.
Europe generates the second-largest cluster, with notable diversity across France (Laboratoire des Signaux et Systèmes/L2S, ESPCI Paris, Institut Langevin, Université Paris-Saclay, CEA, Orange Innovation), Germany (NEC Laboratories Europe, TU Dortmund, Fraunhofer-Gesellschaft), Italy (Politecnico di Milano), Sweden (KTH, Linköping University, Huawei Technologies Sweden), and the UK (Queen Mary University of London, University of Surrey, Imperial College London, University of Nottingham). The EU-funded RISE-6G project (University of Nottingham, 2021) exemplifies multi-national collaborative R&D that is characteristic of European innovation strategy, consistent with OECD frameworks for collaborative technology development.
In the United States, Qualcomm Incorporated stands out as the dominant commercial patent filer, with two active/pending patents on RIS air interface procedures filed in EP and BR jurisdictions in 2025. Futurewei Technologies (Huawei’s US arm) and Arizona State University contribute significant applied research. Dell Products L.P. filed a self-healing AI/ML RIS patent (US, 2025), representing enterprise IT sector entry into the RIS IP landscape. The EP and KR filings from Qualcomm and Korean universities signal that the European and Korean standards ecosystems are active IP battlegrounds, while Chinese operator-level filings reflect imminent commercial deployment ambitions.
Among the 7 patents with explicit jurisdiction data in the 2023–2026 RIS dataset — US (1), EP (2), FR (1), KR (2), CN (1), BR (1) — Qualcomm Incorporated holds two active/pending EP and BR filings directly integrating RIS into 3GPP air interface procedures, representing the most commercially significant IP positions in the dataset.
Five emerging directions shaping the next phase of RIS development
The most recent filings and publications (2023–2026) in this dataset reveal five directional signals that will define the RIS competitive landscape over the next three to five years. Each represents both a technical frontier and an IP opportunity.
1. 3D and non-planar RIS structures
Kongju National University’s March 2026 KR patent introduces a four-plane 3D RIS structure combining 1-bit reflective RIS arrays on multiple faces — enabling omnidirectional signal reception and targeted reflection. This directly overcomes the fundamental limitation of planar surfaces, which can only serve users within a constrained angular range. The filing is the most recent in this dataset and signals that the next hardware generation will move beyond flat-panel form factors.
2. Self-healing, fault-tolerant AI/ML control
Dell’s 2025 US patent introduces local AI/ML tile controllers with federated learning and self-repair via aperture reconfiguration — a direct response to the reliability challenge of deploying large surfaces in real environments where individual subarrays will fail. Federated learning architectures distribute training across many deployed surfaces while preserving a global model, representing the commercially viable trajectory for enterprise-scale RIS infrastructure. Given the dimensionality of joint beamforming, channel estimation, and resource allocation across hundreds of RIS elements, analytical optimization methods are computationally intractable at deployment scale — making AI/ML control not optional but necessary.
3. RIS integration into 3GPP air interface procedures
Qualcomm’s 2025 EP patent on spatial filter correspondence and RACH procedures defines how a UE identifies and uses an RIS-assisted synchronization signal block — directly mapping RIS into standardized access procedures. A second Qualcomm patent covers interference management for RIS via reference signal scheduling (BR, pending, 2025). These filings represent the clearest signal in the dataset of imminent 3GPP standardization activity. R&D teams and IP strategists should monitor 3GPP Study Item and Work Item evolution on RIS and file defensively on protocol-layer interactions before normative specifications lock in.
“Standardization is the immediate battleground. Qualcomm’s air interface patents on RACH procedures and interference management signal that the 3GPP standards process is the critical near-term IP chokepoint for RIS technology.”
4. Energy-autonomous RIS via multi-source harvesting
The wired power supply problem is the most acute practical barrier to large-scale RIS deployment. Fraunhofer-Gesellschaft’s PV-integrated RIS panel (EP, 2025) combines a photovoltaic element and a RIS element on a single surface, converting incident light to electricity while redirecting electromagnetic waves. China Telecom’s dual photovoltaic/RF harvesting supply architecture (CN, 2023) prioritizes solar energy with wireless RF energy harvesting as fallback, removing wired infrastructure dependency entirely. KTH Royal Institute of Technology (2022) formally optimized RIS placement and element configuration to simultaneously maximize SNR and harvest sufficient energy from information signals for autonomous operation. The convergence of these approaches as distinct IP clusters suggests a technology race in autonomous RIS power architectures.
5. Terahertz RIS and near-field operation
The Institute of Microelectronics, A*STAR (Singapore, 2022) explicitly addressed the gap between PIN-diode-based 5G RIS and the requirements of THz 6G links, surveying alternative tuning elements suited to sub-millimeter wavelengths. Tsinghua University (2023) developed near-field (Fresnel zone) RIS beamforming for spherical and cylindrical wave conversion — a necessary evolution as RIS panel sizes grow and the near-field boundary moves outward. Near-field RIS operation simultaneously enables both sensing and communication, directly supporting the Integrated Sensing and Communication (ISAC) functionality that standards bodies including IEEE have identified as a defining 6G capability.
Five emerging directions in RIS technology as of 2026 are: 3D multi-plane structures (Kongju National University, KR patent March 2026), self-healing AI/ML control with federated learning (Dell Products, US patent 2025), integration into 3GPP RACH air interface procedures (Qualcomm, EP patent 2025), energy-autonomous operation via photovoltaic and RF harvesting (Fraunhofer EP 2025, China Telecom CN 2023), and terahertz near-field beamforming (A*STAR 2022, Tsinghua University 2023).
Taken together, these five directions define a clear technology roadmap: from today’s experimental flat-panel passive reflectors to tomorrow’s 3D, self-powered, AI-managed, standards-compliant RIS infrastructure operating at THz frequencies. Organizations with IP positions across multiple directions — particularly at the intersection of AI/ML control, autonomous power, and 3GPP protocol integration — will hold the most defensible competitive positions as 6G deployments begin. The PatSnap IP Intelligence platform and R&D analytics tools are designed to help teams map exactly these intersections before standardization closes the window.