3D Printed Al<sub>2</sub>O<sub>3</sub> for Millimeter Wave Metalens
In this letter, we present a millimeter wave (mmWave) metalens with a gradient refractive index (GRIN) profile. Gradient metamaterials with exquisite structures are designed and manufactured by 3D-printed Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> to realize the corresponding gradient refractive index in the frequency range of 90 GHz to 110 GHz. Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>'s properties of low loss and stable refractive index in the mmWave range will contribute to the achromatic focusing and high transmittance, which is of significant importance in mmWave/THz imaging. Measured electric field distributions demonstrate that achromatic focusing could be achieved with a numerical aperture (NA) of 0.3. The derived full width at half maximum (FWHM) is about 1.5λ. This work proves that ceramic 3D printing technology holds strong potential for wide-ranging applications within the mmWave/THz field.
Authors
- Geng‐Bo Wu (ORCID: https://orcid.org/0000-0002-8226-1663)
- Ka Fai Chan (ORCID: https://orcid.org/0000-0002-5719-6855)
- Chi Hou Chan (ORCID: https://orcid.org/0000-0002-9718-0831)
- Jin Chen (ORCID: https://orcid.org/0000-0001-9554-0445)
Institutions
- City University of Hong Kong (HK)
Publication Details
- Published
- 2025-02-19
- DOI
- https://doi.org/10.1109/iwat64079.2025.10931226
- Primary Topic
- Advanced Antenna and Metasurface Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- City University of Hong Kong
- Natural Science Foundation of Shenzhen City