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MetaLink

John Nolan, Baicheng Chen, Xinyu Zhang

ECE/CSE/ECE, University of California San Diego

SenSys’24 | November 4-8, 2024

Extending Air-to-Water Wireless Communications Using

Passive Bianisotropic Metasurfaces

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Motivation

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Background/Related Works

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Interface Challenges

Asymmetry

High Refraction

Air

Water

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Interface Challenges

Large Water Attenuation

Conduction Loss

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System Overview

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Solution Part 1: Underwater Antenna

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Impedance Mismatch

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Underwater Antenna

  • Stripline transmission line
  • Antenna Array for beamforming

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Solution Part 2: Bypassing Snell’s Law

  • Metasurface to lead RF signal
  • Phase gradient for smooth transition

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Metasurface Design

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Metasurface Design

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  • Refraction beyond Snell’s law
    • -20 in water to 0 degrees in air
  • Meta-atom miniaturization
    • 0.02 Lambda atom size
    • Fits in impedance profile

Air

Water

With Metasurface

Without

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Optimization

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  • Optimal frequency at room temperature ~400MHz

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Evaluation setup

  • USRP B210
  • UHF Air antenna
  • Spectrum analyzer
  • Underwater antenna
  • MetaLink metasurface

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Results (1/2)

Works with Different Angle Requirements

Works Over Longitudinal Period

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Results (2/2)

Robust Against Waves

Extends Along Distance

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Conclusion

  1. MetaLink
    1. Cross Air/Water Boundary
      1. communication/sensing
    2. 3D printed metasurface
    3. Underwater stripline antenna
    4. Bidirectionally improves SNR
    5. Beam steering capability

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  1. More details in our paper ^v^

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