scholarly journals Wideband Metamaterial Absorber Based on Combination of Unit Cells

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Puji Handayani ◽  
Gamantyo Hendrantoro ◽  
Eko Setijadi ◽  
Ahmad Mauludiyanto ◽  
Muhammad Rendy Anggara
Keyword(s):  
Frequency Band ◽  
Wide Band ◽  
Split Ring Resonator ◽  
Metamaterial Absorber ◽  
Simulation Software ◽  
Resonant Frequencies ◽  
Band Frequency ◽  
Wide Frequency Band ◽  
Unit Cells ◽  
Multiple Unit

Metamaterial absorber is an electromagnetic wave absorber made from metamaterial. It basically works in narrow band frequency as it is designed in a particular shape that related to its resonance frequency. However, some applications, e.g., anechoic chamber, require metamaterial absorber that can work in a wide frequency band. This paper discussed the design of wide band metamaterial absorber using the combination of multiple unit cells. The unit cells type was split ring resonator (SRR). SRR had advantages in terms of its simple shape, it could have more than one resonant frequencies depending on the number of its ring, and its shape could be modified easily to obtain the desired resonant frequencies. We designed metamaterial absorber having good absorbtion rate in 2-10 GHz frequency band. To cover this wide frequency band, we used five unit cells which were arranged on a flat plane. Each unit cell had several resonant frequencies. The design was carried out using simulation software of CST (Computer Simulation System). The fabricated design was measured and the results shown that it had an absorbtion rate of 99% in the measured frequency band.

scholarly journals Flexible ultrathin metamaterial absorber for wide frequency band, based on conductive fibers

2018 ◽  
Vol 19 (1) ◽  
pp. 711-717 ◽  
Author(s):  
Young Ju Kim ◽  
Ji Sub Hwang ◽  
Bui Xuan Khuyen ◽  
Bui Son Tung ◽  
Ki Won Kim ◽  
...  
Keyword(s):  
Frequency Band ◽  
Metamaterial Absorber ◽  
Wide Frequency Band ◽  
Conductive Fibers

scholarly journals Design of A Perfect Metamaterial Absorber for Microwave Applications

2021 ◽  
Vol 22 (1) ◽  
pp. 1-4
Author(s):  
Khalid Al-Badri
Keyword(s):  
Normal Incidence ◽  
Metamaterial Absorber ◽  
Absorption Bands ◽  
Band Frequency ◽  
Image Sensing ◽  
Rectangular Patch ◽  
Low Profile ◽  
X Band ◽  
Unit Cells ◽  
Perfect Metamaterial Absorber

In this manuscript, a multi-band and low-profile metamaterial absorber with polarisation independence from 00 to 450 is presented. The proposed metamaterial structure is composed of a single ring with a rectangular patch, consisting of periodic unit cells with a size of 150mm × 250mm × 1.5mm. The structure exhibits three absorption peaks under normal incidence, which cover the X-band. According to the results, the desired material can excellently absorb the electromagnetic wave signal, with an outstanding absorption rate of about 95% at the microwave x-band frequency. The proposed structure shows three absorption bands where two of them exceed 90% absorption level. The results displayed a high Q-factor of 103.5 at a resonance frequency of 8.58 GHz and the figure of merit (FOM) is 98.4, which can be used to enhance the sensor sensing, narrowband band filter and image sensing. The proposed structure is fabricated, and experiments are carried out to validate the design principle. Strong agreements are observed between the measured and the corresponding simulated results.

scholarly journals Entire X-band region metamaterial absorber and reflector with a microstrip patch switch for X-band applications

2019 ◽  
Vol 15 (3) ◽  
pp. 1452
Author(s):  
M.M. Gajibo ◽  
M. K. A. Rahim ◽  
N. A. Murad ◽  
O. Ayop ◽  
H.A. Majid ◽  
...  
Keyword(s):  
Wide Band ◽  
Metamaterial Absorber ◽  
Frequency Range ◽  
Metamaterial Structure ◽  
Band Frequency ◽  
Microstrip Patch ◽  
Band Region ◽  
X Band

<span>A metamaterial structure capable of operating as a wide band absorber as well as an AMC reflector is presented in this report. A microstrip patch copper was used as a switch to switch between the two modes. An FR4 substrate was used and the incidental wave angles were varied from 0<sup>0</sup> to 60<sup>0</sup>. Simulations results showed that the absorber was able achieve 96% absorption at 13.05 GHz and 100% absorption at 10.00 GHz and 12.00 GHz. Furthermore, it archived over 85% absorption for the entire X-band frequency range. The AMC reflector also was able to achieve 84.97%, 82.88% and 78.69% for incident angles 0<sup>0</sup>, 20<sup>0 </sup>and 40<sup>0</sup> respectively. Unfortunately, the structure is polarization sensitive.</span>

Strong absorption of solar energy by using wide band metamaterial absorber designed with plus-shaped resonators

2018 ◽  
Vol 32 (25) ◽  
pp. 1850275 ◽  
Author(s):  
Emin Ünal ◽  
Mehmet Bağmancı ◽  
Muharrem Karaaslan ◽  
Oguzhan Akgol ◽  
Cumali Sabah
Keyword(s):  
Frequency Band ◽  
Metal Layer ◽  
Wide Band ◽  
Metamaterial Absorber ◽  
Dual Band ◽  
Polarization Angle ◽  
Perfect Absorption ◽  
Tem Mode ◽  
Potential Applications ◽  
Absorption Level

A new metamaterial absorber (MA) having distinct properties than those given in the literature is investigated. Although several designs have been studied for achieving absorption characteristics in single-band, dual-band and multiple bands within the whole spectrum of solar light, there has been limited number of researches examining the broadband MA in the visible light section of the spectrum. The designed structure is composed of the combination of three layers having different thicknesses including a metallic substrate, dielectric and a metal layer. Due to the sandwich-like structure, it can support the plasmonic resonance. The proposed structure, which provides a maximum absorption level of 99.42% at 579.26 THz, has a high absorption rate of 99% between the frequency band 545 and 628 THz. Numerical results indicate that the proposed structure has perfect absorption which is greater than 90.98% through the whole working frequency band. The dependency of the designed structure on the polarization angle is investigated for different incident angles with TE and TM polarizations as well as the TEM mode. In addition to its potential applications such as solar cells and cloaking, the designed structure can also be considered as a color sensor and an optical frequency sensor.

scholarly journals Three Different Compact Elliptical Slot Ultra -Wide band Antennas for Wireless Communication Applications

2021 ◽  
pp. 52-59
Author(s):  
K. S Chakradhar ◽  
◽  
V. Malleswara Rao
Keyword(s):  
Frequency Band ◽  
Return Loss ◽  
Wide Band ◽  
Circular Ring ◽  
Ultra Wide Band ◽  
Impedance Bandwidth ◽  
Band Frequency ◽  
Uwb Antennas ◽  
Elliptical Ring ◽  
Pcb Design

From this current paper, 3 separate elliptical slotted ultra- wide band (UWB) antennas are being proposed. These antennas have been designed with a standard PCB design process to be capable of integrating with radiofrequency or microwave circuitry. Two designs were presented in which the initial design comprised a half circular ring radiator and the remaining one considers a half elliptical ring radiator. The third design of the radiator is in the shape of a crescent. The impedance bandwidth of all these presented antenna designs varies from 2.5GHz and reaches to 14GHz with a S11 less than -10GHz. Here, every proposed antenna design also has a consistent radiation pattern across its frequency band of interest. The performance of the antenna is impressive for lower band frequency in UWB system, which differs in a range of 3.1GHz to 5.1GHz. Across the whole frequency band the antenna shows a 10db return loss bandwidth. The antenna is fabricated on RT-duroid substrate and fed with 50 Ω coupled tappered transmission line.

Effects of “Finiteness” on Wave Propagation and Vibration in Elastic Periodic Structures

Aerospace ◽  
2004 ◽  
Author(s):  
Mahmoud I. Hussein ◽  
Gregory M. Hulbert ◽  
Richard A. Scott
Keyword(s):  
Frequency Band ◽  
Vibration Isolation ◽  
Wave Attenuation ◽  
Periodic Structures ◽  
Stop Band ◽  
Forced Response ◽  
Band Frequency ◽  
Mode Localization ◽  
Unit Cells ◽  
Frequency Behavior

The dynamics of finite elastic periodically layered structures is compared to that of the constituent periodic media. The focus is on both the frequency behavior and the spatial response. Through simulations of harmonically induced wave motion within a finite number of unit cells, the frequency band structure and attenuation characteristics of infinite and finite periodic systems are shown to conform under certain conditions. It is concluded that only one or two unit cells of a periodic material are required for “frequency bandness” to carry through to a finite structure, and only three to four unit cells are necessary for significant wave attenuation to take place when the structure is excited at a stop-band frequency. Furthermore, vibration analyses are conducted on a bounded fully periodic structure. The natural frequency spread is shown to conform with the frequency band layout of the infinite periodic material, and the steady-state forced response is observed to exhibit mode localization patterns that resemble those of the infinite periodic medium. These results could be used for setting guidelines for the design of periodic structures for vibration isolation and frequency filtering.

Linear to left- and right-hand circular polarization conversion by using a metasurface structure

2017 ◽  
Vol 10 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Oguzhan Akgol ◽  
Olcay Altintas ◽  
Emin Unal ◽  
Muharrem Karaaslan ◽  
Faruk Karadag
Keyword(s):  
Axial Ratio ◽  
Wide Band ◽  
Polarization Conversion ◽  
Band Frequency ◽  
Left Handed ◽  
Linear Waves ◽  
Polarized Waves ◽  
Unit Cells ◽  
Linearly Polarized ◽  
Parallel Strips

By using a metasurface (MS) structure, a linearly polarized wave is converted to circularly polarized waves. Both right- and left-handed circular polarizations (RHCPs and LHCP) are obtained by a simple configuration in the proposed structure which consists of 16 unit cells arranged in a 4 × 4 layout. Each unit cell contains five horizontal and parallel strips embedded in a rectangular frame in which a single diagonal strip is placed from one corner to the opposed one. It is shown that the orientation of the diagonal line determines the handedness of the converted signal to be either LHCP or RHCP. In order to show the working conditions of the MS structure, scattering parameters are found for both co-polarized and cross-polarized responses. Axial ratio, an indicator for polarization conversion, is then obtained by dividing cross-polar response to co-polar response to demonstrate the transformation. The structure works for horizontally and vertically polarized linear waves in a wide band frequency range which is approximately 510 MHz. Since the suggested MS model is composed of a simple geometry for polarization conversion, it can be easily adjusted in any desired frequency bands for a variety of applications from the defence industry to medical, education, or communication areas.

scholarly journals Inductively tuned modified split ring resonator based quad band epsilon negative (ENG) with near zero index (NZI) metamaterial for multiband antenna performance enhancement

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Moniruzzaman ◽  
Mohammad Tariqul Islam ◽  
Norbahiah Misran ◽  
Md Samsuzzaman ◽  
Touhidul Alam ◽  
...  
Keyword(s):  
Ring Resonator ◽  
Split Ring Resonator ◽  
Simulation Software ◽  
Unit Cell ◽  
Significant Shift ◽  
Antenna Gain ◽  
Split Ring ◽  
Multiband Antenna ◽  
Gain Enhancement ◽  
Unit Cells

AbstractAn inductively tuned modified split-ring resonator-based metamaterial (MTM) is presented in this article that provides multiple resonances covering S, C, X, and Ku-bands. The MTM is designed on an FR-4 substrate with a thickness of 1.5 mm and an electrical dimension of 0.063λ × 0.063λ where wavelength, λ is calculated at 2.38 GHz. The resonator part is a combination of three squared copper rings and one circular ring in which all the square rings are modified shaped, and the inner two rings are interconnected. The resonance frequency is tuned by adding inductive metal strips in parallel two vertical splits of the outer ring that causes a significant shift of resonances towards the lower frequencies and a highly effective medium ratio (EMR) of 15.75. Numerical simulation software CST microwave studio is used for the simulation and performance analysis of the proposed unit cell. The MTM unit cell exhibits six resonances of transmission coefficient (S21) at 2.38, 4.24, 5.98, 9.55, 12.1, and 14.34 GHz covering S, C, X, and Ku-bands with epsilon negative (ENG), near-zero permeability, and near-zero refractive index (NZI). The simulated result is validated by experiment with good agreement between them. The performance of the array of the unit cells is also investigated in both simulation and measurement. The equivalent circuit modeling has been accomplished using Advanced Design Software (ADS) that shows a similar S21 response compared to CST simulation. Noteworthy to mention that with the copper backplane, the same unit cell provides multiband absorption properties with four major absorption peaks of 99.6%, 95.7%, 99.9%, 92.7% with quality factors(Q-factor) of 28.4, 34.4, 23, and 32 at 3.98, 5.5, 11.73 and 13.47 GHz, respectively which can be applied for sensing and detecting purposes. The application of an array of the unit cells is investigated using it as a superstrate of an antenna that provides a 73% (average) increase of antenna gain. Due to its simple design, compact dimension with high EMR, ENG property with near-zero permeability, this multiband NZI metamaterial can be used for microwave applications, especially for multiband antenna gain enhancement.

scholarly journals A hairpin DGS resonator for application to microstrip lowpass filters

2020 ◽  
Vol 71 (2) ◽  
pp. 110-115
Author(s):  
Rong-Bin Chen ◽  
Xiao-Ou Ou
Keyword(s):  
Numerical Simulations ◽  
Frequency Band ◽  
Unit Cell ◽  
Microwave Resonator ◽  
Lowpass Filter ◽  
Separation Angle ◽  
Wide Frequency Band ◽  
Unit Cells ◽  
Scale Ratio ◽  
Experimental Validations

AbstractA hairpin shaped DGS, consisting of two tilted slots with a separation angle, is studied as a unit cell in this contribution. It is further served as a microwave resonator for microstrip lowpass filter applications. Two prototype filters that respectively cascade the same unit cells and the scaled cells with a different scale ratio are analyzed. For demonstration purposes, the two prototype filters are optimally developed, fabricated and examined both from numerical simulations and from experimental validations. Results show the cascaded scaled type demonstrator features a high stopband suppression level within a wide frequency band.

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