An Ultrathin and Ultrawideband Metamaterial Absorber and an Equivalent-Circuit Parameter Retrieval Method

A novel modified-segmented split-ring based symmetric metamaterial absorber is introduced in this paper for X, Ku, and K band applications. The perfect absorption was achieved with a total of 1.91 GHz absorption bandwidth using the conventional FR4 substrate without resistive lumped elements. EM waves were applied in TEM mode at both normal and oblique incidence up to 90° and the same absorptance was found at 11.23 GHz, 14.18 GHz, 17.37 GHz, and 19.18 GHz with the maximum of 85.51%, 99.13%, 98.19%, and 90.8% absorptance respectively. This absorption performance was proved for both co-and crosspolarization analysis. Double negative values of permittivity and permeability up to 17.37 GHz and single negative values of either permittivity or permeability at 19.18 GHz were achieved. An equivalent circuit analysis also proved its performance capability, which makes it a perfect metamaterial absorber. Finally, the comparison of the design with recently published works in terms of unit cell size, absorption band, maximum polarization angles, and cross-polarized absorptivity proved it as a better candidate for the potential use as a perfect absorber. INDEX TERMS Wideband, metamaterial absorber, modified segmented split-ring, X Ku and K band, triple band.

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“…is the wavenumber of air medium and is the thickness of the substrate [27]. The value of 11 in these equations are taken for normal incidence.…”

Section: Figure 13 Absorptance Considering Both Co and Cross-polarizedmentioning

confidence: 99%

“…The equivalent circuit of the unit cell is shown in figure 15 below, as the equivalent circuit approach [27][28][29][30][31] is essential for proving the absorber as perfect MM absorber.…”

Section: Figure 13 Absorptance Considering Both Co and Cross-polarizedmentioning

confidence: 99%

Modified-Segmented Split-Ring Based Polarization and Angle-Insensitive Multi-Band Metamaterial Absorber for X, Ku and K Band Applications

et al. 2020

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“…Hence, there must be a logical and systematic process to design co-polar MM absorbers with target resonances and desired S parameters values so that the MM characteristic can be correlated with the patch design. Equivalent circuit modeling of frequency selective surfaces (FSS) of metamaterials is such an idea that can explain the metamaterial behaviour of the structure 15 , 16 . Few articles have been published describing equivalent circuit analysis for better interpretation of the designed absorber 16 – 26 , but no papers are found for WiFi signal absorber with necessary equivalent circuit analysis.…”

Section: Introductionmentioning

confidence: 99%

Angle-insensitive co-polarized metamaterial absorber based on equivalent circuit analysis for dual band WiFi applications

Hannan

Islam

Faruque

et al. 2021

Sci Rep

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A novel and systematic procedure to design a co-polarized electromagnetic metamaterial (MM) absorber with desired outputs and resonance frequencies for dual-band WiFi signal absorption is presented. The desired resonance frequencies with expected S parameters' values were first designed as an equivalent circuit with extensive analysis and then implemented into frequency-selective MM absorber by numerical simulation with precise LRC elements, satisfying least unit cell area (0.08λ), substrate thickness (0.01λ) and maximum effective medium ratio (12.49). The absorber was simulated for the maximum angle of incidence for both the normal and oblique incidences at co-polarization. The absorptions at the desired resonance frequencies were found at a satisfactory level by both simulation and practical measurement along with a single negative value to ensure metamaterial characteristics. The proposed equivalent circuit analysis approach can help researchers design and engineering co-polarization insensitive MM absorbers using conventional split-ring resonators, with perfection in output and desired resonance frequencies without the necessity of lumped elements or multilayer substrates. The proposed metamaterial can be utilized for SAR reduction, crowdsensing, and other WiFi-related practical applications.

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“…Generally, as the absorption of MM only occurs at the resonant frequency, the absorption bandwidth is considered as narrowband. Consequently, many efforts have been made in order to achieve multiple band [ 32 , 33 , 34 , 35 , 36 , 37 ], broadband [ 15 , 38 , 39 , 40 ], or ultra-wideband [ 6 , 41 ] microwave MM absorbers.…”

Section: Introductionmentioning

confidence: 99%

“…As mentioned before, different methods were used to broaden the absorption bandwidth, but most of them failed to meet all of the aforementioned requirements simultaneously. In other words, the design of broadband microwave MM was mostly focused on one or two frequency bands among the C-band (4–8 GHz) [ 40 , 59 ], X-band (8–12 GHz) [ 15 , 50 , 60 ], Ku-band (12–18 GHz) [ 41 ], or K-band (18–27 GHz) [ 46 ], whereas only few MM designs for absorption in the S-band (2–4 GHz) [ 12 , 52 ] have been reported so far. For the S-band, as the EM wave has the narrowest beam width, it is considered to be an excellent candidate for radar detection.…”

Section: Introductionmentioning

confidence: 99%

Toward an Ultra-Wideband Hybrid Metamaterial Based Microwave Absorber

et al. 2020

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In this paper, we propose a novel design of an ultra-wideband hybrid microwave absorber operating in the frequency range between 2 GHz and 18 GHz. This proposed hybrid absorber is composed of two different layers that integrate a multiband metamaterial absorber and a lossy dielectric layer. The metamaterial absorber consists of a periodic pattern that is composed of an arrangement of different scales of coupled resonators and a metallic ground plane, and the dielectric layer is made of epoxy foam composite loaded with low weight percentage (0.075 wt.%) of 12 mm length carbon fibers. The numerical results show a largely expanded absorption bandwidth that ranges from 2.6 GHz to 18 GHz with incident angles between 0° and 45° and for both transverse electric and transverse magnetic waves. The measurements confirm that absorption of this hybrid based metamaterial absorber exceeds 90% within the above-mentioned frequency range and it may reach an absorption rate of 99% for certain frequency ranges. The proposed idea offers a further step in developing new electromagnetic absorbers, which will impact a broad range of applications.

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An Ultrathin and Ultrawideband Metamaterial Absorber and an Equivalent-Circuit Parameter Retrieval Method

Cited by 78 publications

References 22 publications

Modified-Segmented Split-Ring Based Polarization and Angle-Insensitive Multi-Band Metamaterial Absorber for X, Ku and K Band Applications

Modified-Segmented Split-Ring Based Polarization and Angle-Insensitive Multi-Band Metamaterial Absorber for X, Ku and K Band Applications

Angle-insensitive co-polarized metamaterial absorber based on equivalent circuit analysis for dual band WiFi applications

Toward an Ultra-Wideband Hybrid Metamaterial Based Microwave Absorber

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