Ultra-Wideband Flexible Absorber in Microwave Frequency Band

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.

Download Full-text

Low-profile U-shaped DRA for ultra-wideband applications

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078716000155 ◽

2016 ◽

Vol 9 (3) ◽

pp. 621-627 ◽

Cited By ~ 2

Author(s):

Idris Messaoudene ◽

Tayeb A. Denidni ◽

Abdelmadjid Benghalia

Keyword(s):

Dielectric Resonator ◽

Ground Plane ◽

Ultra Wideband ◽

Impedance Bandwidth ◽

Dielectric Resonator Antenna ◽

Radiation Patterns ◽

Wide Bandwidth ◽

Operating Band ◽

Low Profile ◽

Measurement Results

In this paper, a microstrip-fed U-shaped dielectric resonator antenna (DRA) is simulated, designed, and fabricated. This antenna, in its simple configuration, operates from 5.45 to 10.8 GHz. To enhance its impedance bandwidth, the ground plane is first modified, which leads to an extended bandwidth from 4 to 10.8 GHz. Then by inserting a rectangular metallic patch inside the U-shaped DRA, the bandwidth is increased more to achieve an operating band from 2.65 to 10.9 GHz. To validate these results, an experimental antenna prototype is fabricated and measured. The obtained measurement results show that the proposed antenna can provide an ultra-wide bandwidth and a symmetric bidirectional radiation patterns. With these features, the proposed antenna is suitable for ultra-wideband applications.

Download Full-text

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.

Download Full-text

A Low Profile Asterick-Shaped Polarization Free Metamaterial-Inspired Absorber for Penta-Band Characteristics

10.21203/rs.3.rs-715717/v1 ◽

2021 ◽

Author(s):

Raghvenda Kumar Singh ◽

Ashish Gupta ◽

Akash Yadav ◽

Nishchay Gupta ◽

Utkarsh Tyagi

Keyword(s):

Radio Frequency Identification ◽

Electromagnetic Compatibility ◽

Absorption Mechanism ◽

Stealth Technology ◽

Low Profile ◽

Symmetric Geometry ◽

Frequency Identification ◽

Polarization Insensitive ◽

Independent Behavior ◽

Electrical Thickness

Abstract A penta-band absorber is proposed and developed exhibiting ultra thin and polarization insensitive behavior. It has been designed to be operated in S, C and Ku bands with absorptions peaks at more than 95%. Proposed absorber is processed on a FR4 Glass Epoxy laminate with equivalent electrical thickness of 0.0108 λ0 where λ0 is the wavelength corresponding to the lowest frequency of operation. This confirms the ultra-thin nature of the structure. The absorption pattern of the proposed structure has been characterized under normal and oblique incidence followed by their experimental verification. Presented results demonstrate highly polarization-independent behavior of the proposed absorber due to its symmetric geometry. Also, the electromagnetic field distributions have been studied to acquire better insight of the absorption mechanism corresponding to distinct elements presented in the structure. Then the suggested structure is characterized in terms of its behavior as metamaterial, which ensures the miniaturization. The proposed absorber is suitable to be used in applications like radar cross section reduction, stealth technology, radio frequency identification and electromagnetic compatibility.

Download Full-text

Design and Analysis of a Five-Band Polarization-Insensitive Metamaterial Absorber

International Journal of Antennas and Propagation ◽

10.1155/2020/8827517 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Han Wu ◽

Shijun Ji ◽

Ji Zhao ◽

Chengxin Jiang ◽

Handa Dai

Keyword(s):

Dielectric Layer ◽

Layer Structure ◽

Surface Current ◽

Metamaterial Absorber ◽

Microwave Range ◽

Absorption Mechanism ◽

Resonant Frequencies ◽

Resonator Structure ◽

Dipole Resonance ◽

Polarization Insensitive

A five-band metamaterial absorber (MMA) is presented. The proposed absorber consists of a three-layer structure of the top metal resonator, intermediate dielectric layer, and bottom metal plane. The top structure takes the centroid as the center and spreads out in a three-pronged shape with an average of 360°, and the ends bifurcate again. The calculation was carried out by the professional software to iteratively optimize the absorption effect of MMA in the microwave range. The results show that the MA has five peaks at resonant frequencies of 5.984 GHz, 12.232 GHz, 18.128 GHz, 18.414 GHz, and 20.592 GHz, with peaks of 0.9925, 0.9968, 0.9783, 0.9754, and 0.9975. By analyzing the electromagnetic field and surface current distribution of the absorber, the absorption mechanism is further verified, and the corresponding influence on the absorption spectrum is studied according to different polarization angles and incident angles. The effects of different resonator structure size and dielectric layer thickness on absorption rate were also discussed, and the distribution of electromagnetic fields is analyzed to reveal the existence of electric dipole resonance and magnetic resonance. Through comparing experiments and simulations, it is found that the peaks of the 1st, 2nd, and 5th have smaller absorption errors and frequency deviation, while the peaks of the 3rd and 4th have large ones. The five-band absorber has potential application in multiband electromagnetic stealth, bionic sensor, thermal radiation measuring instrument, and so on.

Download Full-text

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.

Download Full-text

A Polarization-Insensitive and Wide-Angle Terahertz Absorber with Ring-Porous Patterned Graphene Metasurface

Nanomaterials ◽

10.3390/nano10071410 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1410 ◽

Cited By ~ 1

Author(s):

Hongyang Shen ◽

Fengxiang Liu ◽

Chunyang Liu ◽

Dong Zeng ◽

Banghong Guo ◽

...

Keyword(s):

Absorption Band ◽

Dielectric Layer ◽

Incident Angle ◽

Normal Incidence ◽

Transverse Magnetic ◽

Photonic Devices ◽

Geometric Parameters ◽

Polarization Angle ◽

Terahertz Absorber ◽

Polarization Insensitive

A broadband terahertz (THz) absorber, based on a graphene metasurface, which consists of a layer of ring-porous patterned structure array and a metallic mirror separated by an ultrathin SiO2 dielectric layer, is proposed and studied by numerical simulation. The simulated results show that the absorptivity of the absorber reaches 90% in the range of 0.91–1.86 THz, and the normalized bandwidth of the absorptivity is 68.6% under normal incidence. In the simulation, the effects of the geometric parameters of the structure on the absorption band have been investigated. The results show that the absorber is insensitive to the incident polarization angle for both transverse electric (TE) and transverse magnetic (TM) under normal incidence. In addition, the absorber is not sensitive to oblique incidence of the light source under TE polarization conditions, and has an approximately stable absorption bandwidth at the incident angle from 0° to 50°. The absorption band can be adjusted by changing the bias voltage of the graphene Fermi level without varying the nanostructure. Furthermore, we propose that a two-layer graphene structure with the same geometric parameters is separated by a dielectric layer of appropriate thickness. The simulated results show that the absorptivity of the two-layer absorber reaches 90% in the range of 0.83-2.04 THz and the normalized bandwidth of the absorptivity is 84.3% under normal incidence. Because of its excellent characteristics based on graphene metamaterial absorbers, it has an important application value in the field of subwavelength photonic devices.

Download Full-text

Ultra-wideband and Low-profile Absorber with Polarization-insensitive and Wide-angle Properties

2020 International Conference on Microwave and Millimeter Wave Technology (ICMMT) ◽

10.1109/icmmt49418.2020.9386481 ◽

2020 ◽

Author(s):

Qiang Gao ◽

Xiao-Qiu Li ◽

Bao-Jun Niu ◽

Da Li

Keyword(s):

Ultra Wideband ◽

Wide Angle ◽

Low Profile ◽

Polarization Insensitive

Download Full-text

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.

Download Full-text

Design of Miniaturized and Polarization-Insensitive Double-Layer Frequency Selective Surface Based on Meander Lines

International Journal of Antennas and Propagation ◽

10.1155/2021/9576494 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Feifei Huo ◽

Fei Liu ◽

Min Zhu ◽

Jianhui Bao

Keyword(s):

Resonant Frequency ◽

Frequency Shift ◽

Incident Angle ◽

Frequency Selective Surface ◽

Measurement Results ◽

Polarization Insensitive ◽

Spiral Shape ◽

Simulation Results ◽

Frequency Selective ◽

Meander Lines

The work presented in this paper concerns a method for the miniaturized frequency selective surface (FSS) based on the meander lines. A miniaturized dual-bandstop FSS structure based on meander lines with spiral-shape is proposed and simulated. The equivalent circuit and current distributions are introduced to explain the FSS performance. The size of the unit cell is 10 mm, which is about 0.037 wavelength at the first resonant frequency. Simulation results indicate that the proposed FSS has a frequency shift smaller than 1% for different polarizations with an oblique incident angle of 60°. A prototype of the FSS is fabricated and measured. The measurement results show that the FSS is polarization-insensitive and angle-insensitive.

Download Full-text