Reflecting Metasurface Unit Cell Design with Multi-Bit Azimuthal Control

Rains, James; Kazim, Jalil ur Rehman; Zhang, Lei; Abbasi, Qammer H.; Imran, Muhammad Ali; Tukmanov, Anvar

doi:10.1109/icmac54080.2021.9678298

Cited by 4 publications

(5 citation statements)

References 14 publications

(18 reference statements)

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“…The unit cell employed in this work is the multi-bit columndriven planar design depicted in Fig. 1, which was recently introduced by the authors [19]. Each unit cell consists of 5 patches connected by 3 PIN diodes and a capacitor, mounted on a 5mm PTFE-based F4BM-2 substrate with relative permittivity ϵ r = 2.65 and loss tangent tanδ = 0.001.…”

Section: A Unit Cell Designmentioning

confidence: 99%

See 1 more Smart Citation

High-Resolution Programmable Scattering for Wireless Coverage Enhancement: An Indoor Field Trial Campaign

Rains

Kazim

Tukmanov

et al. 2023

IEEE Trans. Antennas Propagat.

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This paper presents a multi-bit reconfigurable intelligent surface (RIS) with a high phase resolution, capable of beam-steering in the azimuthal plane at sub-6 Gigahertz (GHz). Field trials in realistic indoor deployments have been carried out, with coverage enhancement performance ascertained for three common wireless communication scenarios. Namely, serving users in an open lobby with mixed line of sight and nonline of sight conditions, communication via a junction between long corridors, and a multi-floor scenario with propagation via windows. This work explores the potential for reconfigurable intelligent surface (RIS) deployment to mitigate non-line of sight effects in indoor wireless communications. In a single transmitter, single receiver non-line of sight link, received power improvement of as much as 40 dB is shown to be achievable by suitable placement of a RIS, with an instantaneous bandwidth of at least 100 MHz possible over a 3 to 4.5 GHz range. In addition, the effects of phase resolution on the optimal power reception for the multi-bit RIS have been experimentally verified, with a 2.65 dB improvement compared to a 1-bit case.

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Section: A Unit Cell Designmentioning

confidence: 99%

“…Patch spacing, g 1 to g 4 0.9 0.4 1.0 0.4 Substrate thickness, h 5.0 geometry optimisation procedure, see [19]. The components used in this unit cell design are Skyworks SMP1321-040LF PIN diodes and an AVX U-Series 3.6 pF 0402 capacitor.…”

Section: A Unit Cell Designmentioning

confidence: 99%

High-Resolution Programmable Scattering for Wireless Coverage Enhancement: An Indoor Field Trial Campaign

Rains

Kazim

Tukmanov

et al. 2023

IEEE Trans. Antennas Propagat.

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“…The RIS utilised in this work is based on the unit cell recently published by ref. 19 and is depicted in Fig. 4.…”

Section: Discussionmentioning

confidence: 99%

Intelligent wireless walls for contactless in-home monitoring

et al. 2022

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Human activity monitoring is an exciting research area to assist independent living among disabled and elderly population. Various techniques have been proposed to recognise human activities, such as exploiting sensors, cameras, wearables, and contactless microwave sensing. Among these, the microwave sensing has recently gained significant attention due to its merit to solve the privacy concerns of cameras and discomfort caused by wearables. However, the existing microwave sensing techniques have a basic disadvantage of requiring controlled and ideal settings for high-accuracy activity detections, which restricts its wide adoptions in non-line-of-sight (Non-LOS) environments. Here, we propose a concept of intelligent wireless walls (IWW) to ensure high-precision activity monitoring in complex environments wherein the conventional microwave sensing is invalid. The IWW is composed of a reconfigurable intelligent surface (RIS) that can perform beam steering and beamforming, and machine learning algorithms that can automatically detect the human activities with high accuracy. Two complex environments are considered: one is a corridor junction scenario with transmitter and receiver in separate corridor sections and the other is a multi-floor scenario wherein the transmitter and receiver are placed on two different floors of a building. In each of the aforementioned environments, three distinct body movements are considered namely, sitting, standing, and walking. Two subjects, one male and one female perform these activities in both environments. It is demonstrated that IWW provide a maximum detection gain of 28% in multi-floor scenario and 25% in corridor junction scenario as compared to traditional microwave sensing without RIS.

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“…This classification is depicted in Figure 7. Beam steerer [59], [60], absorber [61], [62], phase shift circuits [63], holograms [64] , polarization converter [65] [75], modulators [76], beam steerer [77], THz absorber [78] Liquid crystal Negligible power consumption, low cost, less complex, ease of fabrication and wide operating frequency range Inhomogeneities in the liquid crystal director fields, difficult impedance matching and biasing Amplitude, polarization, phase and frequency THz band, mm-wave band, microwave band and visible spectrum Beam steerer [55],…”

Section: A Deep Learningmentioning

confidence: 99%

Going Beyond a Simple RIS: Trends and Techniques Paving the Path of Future RIS

Shafique,

Alhassoun

2024

IEEE Open J. Antennas Propag.

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To have uninterrupted wireless connectivity, higher throughput, and latency rate down to nanoseconds; future networks will rely heavily on higher frequency bands, yet these signals suffer from attenuation and can be easily blocked by objects. Hence, those signals lose strength over longer distances significantly compared to their low-frequency counterparts. To overcome these constraints, reconfigurable intelligent surfaces (RIS) can increase the wireless network capacity and coverage by consciously altering the wireless propagation environment, which makes them one of the key enablers of the 6G communication networks. The potential benefits of RIS-assisted communication systems can be effectively increased using machine learning (ML) to pave the path towards Wireless 2.0, having a vision of digitization, programmability, and intelligence. This paper reviews recent developments in RIS technology with a special emphasis on tuning techniques, hardware concepts, RIS empowered by artificial intelligence techniques, and applications for next generation of networks. Finally, a viewpoint on the difficulties and potential directions of intelligent metasurfaces are also presented.

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Reflecting Metasurface Unit Cell Design with Multi-Bit Azimuthal Control

Cited by 4 publications

References 14 publications

High-Resolution Programmable Scattering for Wireless Coverage Enhancement: An Indoor Field Trial Campaign

High-Resolution Programmable Scattering for Wireless Coverage Enhancement: An Indoor Field Trial Campaign

Intelligent wireless walls for contactless in-home monitoring

Going Beyond a Simple RIS: Trends and Techniques Paving the Path of Future RIS

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