@article{4392d45f91bc4b619030e1894e095d36,
title = "Coupled Solid and Inverse Antenna Stacks Above Metal Ground as Metamaterial Perfect Electromagnetic Wave Absorbers with Extreme Subwavelength Thicknesses",
abstract = "The ability to completely absorb an electromagnetic (EM) wave with a material much thinner than the wavelength is a prerequisite for achieving ultracompact, flexible, and lightweight EM devices. Herein, a metamaterial microwave perfect absorber is demonstrated as thin as 1/1250 of the target wavelength by coupling an array of metal patches to inverse cross metal antennas through a dielectric separator and with a reflector placed underneath. Compared to a conventional three-layer absorber, the modified design reduces the resonance frequency by up to tenfolds without altering the patch and dielectric layers, but by reconfiguring the induced current pathways that reorient the dipolar magnetic fields and dramatically boost the magnetic flux. With the reflector, the stack is framed for perfect absorption at the critical coupling condition, which is identified by monitoring the reflection phase shift across the resonance frequency. The study provides guidelines for shrinking the thickness further and can be extended to other frequencies.",
keywords = "interference theory, inverse antenna, metamaterial perfect absorbers, microwave absorption, ultrathin absorbers",
author = "Minji Kim and Kyungmin Jung and Youmee Choi and Hwang, {Seung Sang} and Hyun, {Jerome K.}",
note = "Funding Information: This research was supported by the Creative Materials Discovery Program (2020M3D1A1110522), 2017R1A5A1015365, and 2019R1C1C1002802 of the National Research Foundation (NRF) funded by Ministry of Science and ICT, and the Industrial Strategic Technology Development Program (10063274) funded by the Ministry of Trade, Industry and Energy (MOTIE, Republic of Korea) as well as the Materials Architecturing Research Center Institutional Program (2E31762) of Korea Institute of Science of Technology. J.K.H. also acknowledges support from Yulchon Chemical Co. Funding Information: This research was supported by the Creative Materials Discovery Program (2020M3D1A1110522), 2017R1A5A1015365, and 2019R1C1C1002802 of the National Research Foundation (NRF) funded by Ministry of Science and ICT, and the Industrial Strategic Technology Development Program (10063274) funded by the Ministry of Trade, Industry and Energy (MOTIE, Republic of Korea) as well as the Materials Architecturing Research Center Institutional Program (2E31762) of Korea Institute of Science of Technology. J.K.H. also acknowledges support from Yulchon Chemical Co. Publisher Copyright: {\textcopyright} 2022 Wiley-VCH GmbH.",
year = "2022",
doi = "10.1002/adom.202101672",
language = "English",
journal = "Advanced Optical Materials",
issn = "2195-1071",
publisher = "John Wiley & Sons Inc.",
}