A Low-Cost Hands-On Laboratory for an Undergraduate Microwave Course

Hum, Sean V.; Okoniewski, M.

doi:10.1109/map.2007.4293967

Cited by 4 publications

(1 citation statement)

References 13 publications

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“…Their results showed that smaller patch antennas with larger ground plane exposure produce higher specular reflection. [78,79] These results have been confirmed and expanded upon in more detailed analyses, which showed that scattering due to phase errors at the zone boundaries (between distinct patch antennas that provide phase responses of −𝛿 and 2𝜋 + 𝛿, 𝛿 being a small phase value) can give rise to specular reflection, [80] and that, more generally, specular reflection that occurs for operational frequencies above or below the design frequency of the reflectarray can be caused by imbalance between the current densities in the patch antenna and the ground plane. [81] A thorough modeling effort was carried out to understand the physical origin of the strong specular reflection observed at all frequencies of our flat-knit metalens and to investigate whether some of the explanations mentioned above for the occurrence of specular reflection in off-broadside reflectarrays are pertinent to our device.…”

Section: Discussion On Flexible Metalens Performancementioning

confidence: 99%

Flat‐Knit, Flexible, Textile Metasurfaces

Carter,

Resneck,

Ra'di

et al. 2024

Advanced Materials

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Lightweight, low‐cost metasurfaces and reflectarrays that are easy to stow and deploy are desirable for many terrestrial and space‐based communications and sensing applications. This work demonstrates a lightweight, flexible metasurface platform based on flat‐knit textiles operating in the cm‐wave spectral range. By using a colorwork knitting approach called float‐jacquard knitting to directly integrate an array of resonant metallic antennas into a textile, we realize two textile reflectarray devices, a metasurface lens (metalens) and a vortex‐beam generator. Operating as a receiving antenna, the metalens focuses a collimated normal‐incidence beam to a diffraction‐limited, off‐broadside focal spot. Operating as a transmitting antenna, the metalens converts the divergent emission from a horn antenna into a collimated beam with peak measured directivity, gain, and efficiency of 21.30 dB, 15.30 dB, and –6.00 dB (25.12%), respectively. The vortex‐beam generating metasurface produces a focused vortex beam with a topological charge of m = 1 over a wide frequency range of 4.1‐5.8 GHz. Strong specular reflection is observed for our textile reflectarrays, caused by wavy yarn floats on the backside of the float‐jacquard textiles. Our work demonstrates a novel approach for scalable production of flexible metasurfaces by leveraging commercially available yarns and well‐established knitting machinery and techniques.This article is protected by copyright. All rights reserved

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