Reconfigurable honeycomb metamaterial absorber having incident angular stability

Abstract Ultrawide-angle electromagnetic wave absorbers with excellent mechanical properties are required in many diverse applications such as sensing, and stealth technologies. Here, a novel 3D reconfigurable metamaterial absorber (MMA) consisting of honeycomb and VO2 films is proposed. The proposed MMA exhibits a strong absorptivity above 90% in the widest incident angle up to $$87^\circ $$ 87 ∘ for TM- and TE polarized oblique incidences for THz wave propagating in yoz-plane. Under normal incidence, when VO2 films are in the insulating state, the proposed absorber exhibits high absorptivity in the frequency band of 1–4 THz. By increasing the temperature of the whole structure, the structural transformation of VO2 occurs and turns into the metallic phase. We have shown that under oblique incidence, the ohmic losses of VO2 films especially those parallel to the direction of the incident electric field are the most important absorption principles of the proposed MMA. Due to the ultra wide-angle absorption (angular stability) and mechanical performance, it is expected that the presented MMA may find potential applications, such as camouflage technologies, electromagnetic interference, imaging, and sensing. To the best knowledge of authors, the proposed MMA configuration exhibits the absorptivity in the widest incident angle ever reported.

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An Ultrathin, Triple-Band Metamaterial Absorber with Wide-Incident-Angle Stability for Conformal Applications at X and Ku Frequency Band

Nanoscale Research Letters ◽

10.1186/s11671-020-03448-0 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Guangsheng Deng ◽

Kun Lv ◽

Hanxiao Sun ◽

Jun Yang ◽

Zhiping Yin ◽

...

Keyword(s):

Free Space ◽

High Efficiency ◽

Incident Angle ◽

Surface Current ◽

Normal Incidence ◽

Metamaterial Absorber ◽

Angle Of Incidence ◽

Perfect Absorption ◽

Absorption Frequency ◽

Unit Cells

AbstractAn ultrathin and flexible metamaterial absorber (MA) with triple absorption peaks is presented in this paper. The proposed absorber has been designed in such a way that three absorption peaks are located at 8.5, 13.5, and 17 GHz (X and Ku bands) with absorption of 99.9%, 99.5%, and 99.9%, respectively. The proposed structure is only 0.4 mm thick, which is approximately 1/88, 1/55, and 1/44 for the respective free space wavelengths of absorption frequency in various bands. The MA is also insensitive due to its symmetric geometry. In addition, the proposed structure exhibits minimum 86% absorption (TE incidence) within 60° angle of incidence. For TM incidence, the proposed absorber exhibits more than 99% absorptivity up to 60° incidence. Surface current and electric field distributions were investigated to analyze the mechanism governing absorption. Parameter analyses were performed for absorption optimization. Moreover, the performance of the MA was experimentally demonstrated in free space on a sample under test with 20 × 30 unit cells fabricated on a flexible dielectric. Under normal incidence, the fabricated MA exhibits near perfect absorption at each absorption peak for all polarization angles, and the experimental results were found to be consistent with simulation results. Due to its advantages of high-efficiency absorption over a broad range of incidence angles, the proposed absorber can be used in energy harvesting and electromagnetic shielding.

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Stereo Perfect Metamaterial Absorber Based on Standing Gear-Shaped Resonant Structure With Wide-Incident-Angle Stability

Frontiers in Physics ◽

10.3389/fphy.2020.609527 ◽

2020 ◽

Vol 8 ◽

Author(s):

Guangsheng Deng ◽

Kun Lv ◽

Hanxiao Sun ◽

Zhiping Yin ◽

Jun Yang

Keyword(s):

Incident Angle ◽

Structural Parameters ◽

Three Dimensional ◽

Dielectric Substrate ◽

Metamaterial Absorber ◽

Center Frequency ◽

Resonant Structure ◽

Potential Applications ◽

Angle Stability ◽

Perfect Metamaterial Absorber

In this work, a single-band metamaterial absorber (MA) based on a three dimensional (3D) resonant structure is presented. The unit cell is composed of a standing gear-shaped resonator, which is embedded in the dielectric substrate. The proposed 3D MA is ultrathin with a total thickness of 2.3 mm, corresponding 0.077λ0 at its center frequency. The simulation results demonstrate a high absorption peak at 10.1 GHz with absorptivity of 99.9%. The proposed 3D MA is insensitive to the polarization of the incident wave due to its rotationally symmetric structure. Moreover, the proposed 3D MA exhibits a wide-incident-angle stability, as absorptivity of more than 85% can be achieved for both TE and TM incidences with incident angle up to 60°. Most importantly, multiband electromagnetic wave absorption of the stereo MA can be enabled by adjusting the structural parameters of the standing gear. The proposed structure is compatible with 3D printing technology and has potential applications in electromagnetic shielding.

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Experimental verification of super-compact ultra-wideband (UWB) polarization and incident angle-independent metamaterial absorber

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720001300 ◽

2020 ◽

pp. 1-11

Author(s):

Manpreet Kaur ◽

Hari Shankar Singh

Keyword(s):

Incident Angle ◽

Low Cost ◽

Surface Current ◽

Cost Effective ◽

Normal Incidence ◽

Metamaterial Absorber ◽

Capacitive Coupling ◽

Ultra Wideband ◽

Absorption Mechanism ◽

The Stability

Abstract In this paper, a super-compact ultra-wideband (UWB) metamaterial absorber (MMA) is presented. The absorber design consists of an inverted L-shaped structure and a diagonal rectangular-shaped structure. The capacitive coupling between these two structures not only provides UWB nature but also provides a super-compact absorber design. The dimension of the unit cell arrangement is 5 × 5 mm2 and printed on a low-cost FR-4 substrate of thickness 1.54 mm (0.061λlowest). The design absorber provides more than 97% absorptivity from 12 to 21 GHz for normal incidence electromagnetic (EM) wave. However, the proposed MMA has a full width at half maximum absorption bandwidth of 11.71 GHz from 10.34 to 22.05 GHz. Moreover, the surface current distributions have been analyzed to understand the absorption mechanism of the MMA. The stability of the proposed design is validated with different incident angles (for TE and TM modes) and different polarization angles. Finally, the absorber design is fabricated and verified experimentally. Furthermore, the UWB frequency range, high absorption, ease in design and fabrication, and cost-effective make it suitable for different quality applications in stealth technology, thermal imaging, radar detection, antenna systems, and other EM devices.

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Reversibly-propagational metamaterial absorber for sensing application

Modern Physics Letters B ◽

10.1142/s0217984918500446 ◽

2018 ◽

Vol 32 (04) ◽

pp. 1850044 ◽

Cited By ~ 3

Author(s):

Bui Son Tung ◽

Bui Xuan Khuyen ◽

Young Joon Yoo ◽

Joo Yull Rhee ◽

Ki Won Kim ◽

...

Keyword(s):

Oblique Incidence ◽

Geometrical Structure ◽

Incident Angle ◽

Metamaterial Absorber ◽

Perfect Absorber ◽

Perfect Absorption ◽

Great Magnitude ◽

X Band ◽

Sensing Application ◽

Metamaterial Perfect Absorber

We investigated a reversibly-propagational metamaterial perfect absorber (MPA) for X band using two separated identically-patterned copper layers, which were deposited on continuous dielectric FR-4 layers. By adjusting oblique incidence, two separated resonances are excited, then come close to each other and is finally merged to be a perfect absorption peak at 10.1 GHz. The nature of resonance is the quadrupole mode instead of the fundamental resonances in common MPAs. The mechanism of perfect absorption is the coupling of two quadrupole resonances at their superposition, leading to an enhancement of energy absorption. Finally, we numerically presented the capability of sensing thin resonant substance using the proposed MPA. The characteristic resonance of substance, which does not appear on the absorption spectrum at the limited thickness of bare substance layer, is detected with a great magnitude of signal by exploiting the absorption resonance of MPA. Our work provides another way to obtain the reversibly-propagational absorption by controlling the incident angle instead of the geometrical structure, and might be useful for the potential devices based on MPA such as detectors and sensors.

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Analysis of ultrasonic waves generated by oblique incidence of a laser

Insight - Non-Destructive Testing and Condition Monitoring ◽

10.1784/insi.2019.61.12.714 ◽

2019 ◽

Vol 61 (12) ◽

pp. 714-719

Author(s):

O Saito ◽

N Higuchi ◽

E Sen ◽

Y Okabe

Keyword(s):

Laser Beam ◽

Oblique Incidence ◽

Incident Angle ◽

Normal Incidence ◽

Ultrasonic Waves ◽

Laser Ultrasonic ◽

Ultrasonic Devices ◽

Entire Object ◽

Inspection Techniques ◽

Non Destructive

Laser ultrasonic waves are promising tools for non-destructive inspection in various industries. To inspect an entire object, the laser beam must scan the complete surface of the object. The incident angle of the laser beam will then differ depending on the location on the object that is irradiated. While oblique incidence of the laser beam will excite ultrasonic waves, there is a possibility that these waves will be different from those excited at normal incidence. For the establishment of reliable inspection techniques, a deeper understanding of laser ultrasonic waves is required. In this paper, the generation of ultrasonic waves by lasers at oblique incidence is numerically investigated. An integral expression for the temperature distribution that satisfies the thermal conduction is derived and then finite element method (FEM) simulations of the generated elastic waves are performed. In the case of a small incident angle of the laser beam, the directional dependence of the generated ultrasonic waves is small. However, with a large incident angle, the generated waves exhibit directionality in the wave intensity. Although the incident angle does not need to be considered in the ordinary use of laser ultrasonic devices, the detectability of defects may be affected when the angle is very large.

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Calculation of the Ion Optical Properties of Inhomogeneous Magnetic Sector Fields Part 3: Oblique Incidence and Exit at Curved Boundaries

Zeitschrift für Naturforschung A ◽

10.1515/zna-1959-0911 ◽

1959 ◽

Vol 14 (9) ◽

pp. 822-827 ◽

Cited By ~ 22

Author(s):

H. A. Tasman ◽

A. J. H. Boerboom ◽

H. Wachsmuth

Keyword(s):

Oblique Incidence ◽

Normal Incidence ◽

Second Order ◽

Resolving Power ◽

High Mass ◽

Curved Boundaries ◽

Magnetic Sector ◽

Mass Resolving Power ◽

Mass Dispersion ◽

Fringing Fields

In previous papers 1.2we presented the radial second order imaging properties of inhomogeneous magnetic sector fields with normal incidence and exit at plane boundaries. These fields may provide very high mass resolving power and mass dispersion without increase in radius or decrease of slit widths. In the present paper the calculations are extended to include the effect of oblique incidence and exit at curved boundaries. The influence of the fringing fields on axial focusing when the boundaries are oblique, is accounted for. It is shown that the second order angular aberration may Le eliminated by appropriate curvature of the boundaries.

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Polypropylene/Carbon Fiber Composite Layered Materials: Electromagnetic Interference Shielding Effect and Mechanical Performance

Fibers and Polymers ◽

10.1007/s12221-021-0007-0 ◽

2021 ◽

Author(s):

Mei-Feng Lai ◽

Chen-Hung Huang ◽

Jia-Horng Lin ◽

Yu-Chun Chuang ◽

Ching-Hua Wang ◽

...

Keyword(s):

Carbon Fiber ◽

Electromagnetic Interference ◽

Mechanical Performance ◽

Fiber Composite ◽

Layered Materials ◽

Shielding Effect ◽

Electromagnetic Interference Shielding ◽

Carbon Fiber Composite

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Predicting Electromagnetic Interference to a Terminated Wire Using Characteristic Mode Analysis

Applied Computational Electromagnetics Society ◽

10.47037/2020.aces.j.351128 ◽

2021 ◽

Vol 35 (11) ◽

pp. 1318-1319

Author(s):

Mohamed Hamdalla ◽

Anthony Caruso ◽

Ahmed Hassan

Keyword(s):

Electromagnetic Interference ◽

Incident Angle ◽

Electromagnetic Coupling ◽

Ground Plane ◽

Mode Analysis ◽

Characteristic Mode ◽

Work Characteristic

Electromagnetic coupling to realistic wire configurations exhibit large variations with respect to the frequency, incident angle, and polarization of the interfering signal. In this work, Characteristic Mode Analysis (CMA) is used to calculate the fundamental modes of a terminated wire above an infinite ground plane. Using the properties of the modes, the coupled currents to the wire’s loads are predicted for different incident excitations. Using this simple but practical wire configuration, we show the versatility of CMA in practical electromagnetic interference and coupling applications.

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