Ultrathin optically transparent electromagnetic shielding window with broadband microwave absorption and ultrahigh optical transmittance

Abstract

In this work, we propose an optically transparent metamaterial absorber (OTMMA) based electromagnetic interference shielding window with broadband microwave absorption and ultrahigh optical transmittance. Such a window with relative thickness of λ 0 /21.4 at the lowest frequency consists of a three-layer structure in which two indium-tin-oxide films with different patterns are etched on the upper and lower surfaces of a glass substrate. The specific design feature realizes more than 90% microwave absorption covering a wide frequency range of 7.84-12.35 GHz and makes the window insensitive to the incident angle and polarization state of the incident microwave. Importantly, the measured shielding effectiveness

Low-profile reconfigurable saline water-based ultrawideband metamaterial absorber

“…This was a significant step forward in the field of microwave and terahertz wave absorptions. Based on previous solutions for expanding the absorption bandwidth, there are four common methods: multilayer structures [14][15][16][17], loading lumped elements [18], 3D structures [19], and using liquid structures [20,21]. These methods have been explored extensively and are known to be effective in their respective applications.…”

Multifunctional Green Electromagnetic Interference Shielding Material for the Sub-6-GHz Band

“…MMAs bring the design and development of absorbing shielding materials into a new world, but few articles discuss their SE . − With further increase in demand, EMI shielding materials with only high shielding ability no longer meet the shielding requirement in some particular scenarios, such as the windows of aircraft or vehicles, curved objects, and so on. Thus, some EMI shielding materials with optical transparency or/and flexible performances have been successively proposed. − Ref reported a transparent and flexible EMI shielding film, which exhibits a high transmittance of 90% and SE of 24.9 dB at 8.2 GHz, whose shielding mechanism is reflection. Li et al prepared a flexible, optically opaque EMI shielding material with an SE (29–31 dB) in the frequency range of 0.5–3 GHz .…”

“…Li et al prepared a flexible, optically opaque EMI shielding material with an SE (29–31 dB) in the frequency range of 0.5–3 GHz . Based on MMA, two EMI absorbing shielding materials were proposed in refs and , respectively. One had an optical transmittance of up to 93% and an SE above 23 dB at 7.84–12.35 GHz, and the other had an optical transmittance of 73.1% with an SE above 18.25 dB at 7.0–18.0 .…”

“…Based on MMA, two EMI absorbing shielding materials were proposed in refs and , respectively. One had an optical transmittance of up to 93% and an SE above 23 dB at 7.84–12.35 GHz, and the other had an optical transmittance of 73.1% with an SE above 18.25 dB at 7.0–18.0 . However, their substrates were both hard glass.…”

“…However, as H 2 O and CO 2 and so on in the atmosphere have a strong absorption of infrared radiation in certain bands, the infrared radiation only has 0.7–2.6, 3–5, and 8–14 μm bands left . In recent years, many efforts have been made on the design of multifunctional materials, which can simultaneously shield microwave and IR radiation based on conventional materials , and MMAs. , With the help of melamine-based hybrid foam, an IR and EMI shielding opaque material with ultralow IR emissivity (∼0.1) at 3–14 μm and an ultrahigh SE = 47 dB at the X band was proposed. However, its shielding mechanism was reflection .…”