An ultra-wideband, polarization insensitive, and wide incident angle absorber based on an irregular metamaterial structure with layers of water

In this paper, an ultra-wideband flexible absorber is proposed. Based on a summary of the absorption mechanism, using lossless air to replace the heavy lossy dielectric layer will not substantially impact the absorption. The dielectric layer is only a thin layer of polyimide. The proposed absorber is a sandwich structure. The surface is a layer of copper metal ring and wire, and it is loaded with chip resistors to expand the absorber bandwidth. Simulated results show that the bandwidth of the proposed absorber, with an absorptivity of more than 90%, is 2.55–10.07 GHz, with a relative bandwidth over 119.2%. When the electromagnetic wave has a wide incident angle, the absorber still maintains a high absorption. This absorber has been fabricated by FPC (flexible printed circuit) technology. The proposed absorber was attached to the cylinder and measured. The measurement results are roughly the same as the simulation results. The fabricated absorber is easy to carry and flexible, such that it can easily be conformed to irregular objects. The proposed absorber is polarization-insensitive, low profile, thin, and portable, so it is easier to apply in a variety of practical fields.

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An ultra-wideband, polarization insensitive metamaterial absorber based on multiple resistive film layers with wide-incident-angle stability

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720000513 ◽

2020 ◽

pp. 1-9

Author(s):

Guangsheng Deng ◽

Kun Lv ◽

Hanxiao Sun ◽

Yuan Hong ◽

Xiaoying Zhang ◽

...

Keyword(s):

Incident Angle ◽

Metamaterial Absorber ◽

Parameter Analysis ◽

Ultra Wideband ◽

High Symmetry ◽

Large Wave ◽

Absorption Frequency ◽

Resistive Film ◽

Absorption Bandwidth ◽

Polarization Insensitive

Abstract In this work, we propose a broadband, polarization-insensitive and wide incident angle stable metamaterial absorber (MA) based on the resistive film. The absorber consists of a three-layer structure with each layer of dielectric substrate printed with different shapes of resistive film. The multilayer structure not only extends the absorption bandwidth but also maintains high absorption under large wave incident angles. Numerical simulation shows that the absorptivity of a normal incident wave is above 90% in the frequency range 2.34–18.95 GHz, corresponding to a relative absorption bandwidth of 156%. Moreover, the whole MA structure has a total thickness of 11.3 mm, corresponding to 0.09 λ0 at its lowest absorption frequency. Due to the high symmetry of the structure, the absorber has good polarization insensitivity. In addition, for both transverse electric and transverse magnetic incidence, the proposed absorber achieves an absorptivity of more than 80% at incident angles of up to 45° and thus has good stability for wide incident angles. The absorption principle of the absorber is analyzed by the surface current and power loss density distribution. Parameter analysis is also performed for bandwidth optimization. Due to its advantages of wideband absorption with high efficiency, the proposed absorber has the potential to be applied to the energy-harvesting and electromagnetic stealth fields.

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A Compact Ultra-Wideband Polarization-Insensitive Metamaterial Absorber at 5G Millimeter Wave Band

2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) ◽

10.1109/nemo49486.2020.9343462 ◽

2020 ◽

Author(s):

Xiaoyong LEI ◽

Shuyun HUO ◽

Mengjun WANG ◽

Yan LI ◽

Erping LI

Keyword(s):

Millimeter Wave ◽

Metamaterial Absorber ◽

Ultra Wideband ◽

Wave Band ◽

Millimeter Wave Band ◽

Polarization Insensitive

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Angle and polarization-independent miniaturized UWB FSS design

International Journal of Microwave and Wireless Technologies ◽

10.1017/s175907872000166x ◽

2021 ◽

pp. 1-9

Author(s):

Yanning Yuan ◽

Yuchen Zhao ◽

Xiaoli Xi

Keyword(s):

Design Method ◽

Incident Angle ◽

Stop Band ◽

Single Layer ◽

Wireless Systems ◽

Frequency Selective Surface ◽

Ultra Wideband ◽

Band Frequency ◽

Gain Enhancement ◽

Polarization Independent

Abstract A single-layer ultra-wideband (UWB) stop-band frequency selective surface (FSS) has several advantages in wireless systems, including a simple design, low debugging complexity, and an appropriate thickness. This study proposes a miniaturized UWB stop-band FSS design. The proposed FSS structure consists of a square-loop and metalized vias that are arranged on a single layer substrate; it has an excellent angle and polarization-independent characteristics. At an incident angle of 60°, the polarization response frequencies of the transverse electric and magnetic modes only shifted by 0.003 f0 and 0.007 f0, respectively. The equivalent circuit models of the square-loop and metallized vias structure are analysed and the accuracy of the calculation is evaluated by comparing the electromagnetic simulation. The 20 × 20 array constitutes an FSS reflector with a unit size of 4.2 mm × 4.2 mm (less than one-twentieth of the wavelength of 3 GHz), which realizes an UWB quasi-constant gain enhancement (in-band flatness is <0.5 dB). Finally, the simulation results were verified through sample processing and measurement; consistent results were obtained. The FSS miniaturization design method proposed in this study could be applied to the design of passband FSS (complementary structure), antennas and filters, among other applications.

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An Ultra-Wideband THz/IR Metamaterial Absorber Based on Doped Silicon

Materials ◽

10.3390/ma11122590 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2590 ◽

Cited By ~ 2

Author(s):

Huafeng Liu ◽

Kai Luo ◽

Shihao Tang ◽

Danhua Peng ◽

Fangjing Hu ◽

...

Keyword(s):

Incident Angle ◽

Average Power ◽

Far Infrared ◽

Metamaterial Absorber ◽

Ultra Wideband ◽

Broadband Absorption ◽

Wide Range ◽

Doped Silicon ◽

Simulated Field ◽

Underlying Mechanisms

Metamaterial-based absorbers have been extensively investigated in the terahertz (THz) range with ever increasing performances. In this paper, we propose an all-dielectric THz absorber based on doped silicon. The unit cell consists of a silicon cross resonator with an internal cross-shaped air cavity. Numerical results suggest that the proposed absorber can operate from THz to far-infrared regimes, having an average power absorption of ∼95% between 0.6 and 10 THz. Experimental results using THz time-domain spectroscopy show a good agreement with simulations. The underlying mechanisms for broadband absorption are attributed to the combined effects of multiple cavities modes formed by silicon resonators and bulk absorption in the doped silicon substrate, as confirmed by simulated field patterns and calculated diffraction efficiency. This ultra-wideband absorption is polarization insensitive and can operate across a wide range of the incident angle. The proposed absorber can be readily integrated into silicon-based photonic platforms and used for sensing, imaging, energy harvesting and wireless communications applications in the THz/IR range.

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A Switchable Ultra-Wideband Metamaterial Absorber with Polarization-Insensitivity and Wide-incident Angle at THz Band

Frontiers in Materials ◽

10.3389/fmats.2021.729495 ◽

2021 ◽

Vol 8 ◽

Author(s):

Liansheng Wang ◽

Dongyan Xia ◽

Quanhong Fu ◽

Xueyong Ding ◽

Yuan Wang

Keyword(s):

Incident Angle ◽

Ground Plane ◽

Surface Current ◽

Dielectric Substrate ◽

Metamaterial Absorber ◽

Ultra Wideband ◽

Absorption Mechanism ◽

Te Mode ◽

Polarization Insensitivity ◽

High Absorption

In this paper, we report a switchable ultra-wideband metamaterial absorber with polarization-insensitivity and wide-incident angle at THz band which is composed of VO2 disk, polyimide dielectric substrate, and gold ground plane. The results show that the absorption is greater than 90% from 3.5–8 THz for a temperature of 300 K and this absorption band disappears when the temperature rises to 350 K. The absorption property of our proposed metamaterial absorber is insensitive to polarization states and angles and it can withhold high absorption of more than 80% for wide-incident angles, up to 60° for TE mode and TM mode. The wideband absorption mechanism is elucidated using an effective medium and surface current analysis.

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