Triple Band Research Articles

Enhanced Sensing Capacity of Terahertz Triple-Band Metamaterials Absorber Based on Pythagorean Fractal Geometry.

A new design of a triple band perfect metamaterial absorber based on Pythagorean fractal geometry is proposed and analyzed for terahertz sensing applications. The proposed design showed an enhanced sensing performance and achieved three intensive peaks at 33.93, 36.27, and 38.39 THz, corresponding to the absorptivity of 98.5%, 99.3%, and 99.6%, respectively. Due to the symmetrical nature of the recommended design, the structure exhibited the characteristics of independency on the incident wave angles. Furthermore, a parametric study was performed to show the effects of the change in substrate type, resonator material, and substrate thickness on the absorption spectrum. At a fixed analyte thickness (0.5 μm), the resonance frequency of the design was found to be sensitive to the refractive index of the surrounding medium. The proposed design presented three ultra-sensitive responses of 1730, 1590, and 2050 GHz/RIU with the figure of merit (FoM) of 3.20, 1.54, and 4.28, respectively, when the refractive index was changed from 1.0 to 1.4. Additionally, the metamaterial sensor showed a sensitivity of 1230, 2270, and 1580 GHz/μm at the three resonance frequencies, respectively, when it was utilized for the detection of thickness variation at a fixed analyte refractive index (RI) of 1.4. As long as the RI of the biomedical samples is between 1.3 and 1.4, the proposed sensor can be used for biomedical applications.

A compact triple band circular polarized slotted microstrip patch antenna with low frequency ratio

A pentagon shaped triple band circular polarized (CP) slotted microstrip patch antenna with asymmetric single microstrip feed line is designed. The proposed patch antenna is loaded with a pair of asymmetric slits, a pair of symmetric slots and a triangle shape truncation at the right side of the antenna. The antenna is drafted within the size of 0.43λ × 0.43λ and resonates at 2.17, 3.08, and 3.48 GHz with impedance bandwidth (IBW; IS11I < −10 dB) 2.14–2.20, 3.06–3.10, and 3.45–3.51 GHz, respectively. The Axial Ratio Bandwidth (ARBW; AR < 3 dB) is obtained as 2.17–2.40, 3.07–3.10, and 3.48–3.54 GHz at the three resonances which almost cover the IBW. An additional feature of the design is that the CP bands are very closely spaced with frequency ratio of 1.36 between first and second CP resonances and 1.13 between second and third CP resonances. The obtained gain at three resonances is 3.9, 3.79, and 4.81, respectively. The CP radiation patterns are found to be stable with good right hand CP (RHCP) to left hand CP (LHCP) isolation at the boresight direction. This antenna is suitable for S-band applications. The advantage of the proposed design has been highlighted with respect to multiband CP, CP frequency ratio, compactness and RHCP to LHCP isolation. A prototype of the proposed design is fabricated and the measured results are in accord with the simulated results.

Microstrip feed dual band and triple band frequency reconfigurable antenna for diverse applications

A compact reconfigurable antenna which can operate at wide range of frequency bands like ITU-band (7.725 GHz– 8.5 GHz), X-band (8-12.5GHz) and Wi-Fi (3.6 GHz, 5 GHz, and 5.9 GHz) very efficiently with gain ranging from 10dB to 12dB which can be useful for commercial applications is designed. A circular shaped antenna with microstrip line feeding is designed with highest switching rate with the abet of two-diodes which provides state of flexibility in terms of frequency reconfigurability, number of operating bands, frequency reconfigurability and stable radiation pattern with easily fabricating opportunities consists of stub loaded circular patch radiator. The novelty of proposed ultramodern antenna in terms of the band-width frequency reconfigurability, and multiple operating modes are achieved due to the collation performance of the suggested antenna operates in commercial applications.

Single-Feed Triple Band Microstrip Antenna for High Frequencies

This project presented a Design of a Single feed microstrip antenna has proposed for the Triple band operations and at the same time it mainly designed for satellite communication and the applications in K/Ka/Ku bands it is easy to fabricate, and high flexibility and improved antenna improved efficiency. The antenna has small dimensions of 70×29×0.787 and operates at 1GHz. This antenna mainly consists of a microstrip line in the center, two slot-loaded rectangular patches on the lateral sides, with two thin microstrip lines. The antenna is designed and simulated on High-Frequency Structure Simulator (HFSS) platform using Rogers RT/Duroid 5880 substrate with 0.787 dielectric constant and 0.002 loss tangent. The radiation pattern, return loss, vswr and gain results reveal that the antenna performs quite well at all frequencies.

Axial ratio tuned disk‐shapedS‐bandtriple notch circularly polarized slot antenna

Microstrip-line fed annular ring circularly polarized antenna is proposed in this work. The antenna is fabricated on a disk-shaped FR-4 substrate with annular ring slots etched in the ground. The overall space requirement of the antenna is 25 × 25 × 1.6 mm3. The antenna is modeled for triple notch wide band circular polarization operation in the frequency range from 2–4 GHz. A wide impedance band operation is be obtained by the introduction of slots and stubs. An impedance band- width of 1.8 GHz is accomplished with three notches at 2.4, 2.8, and 3.3 GHz.

Performance Evaluation of Triple band Microstrip Antenna using Hybrid SRRs on Fractal Ground Plane

A single-band monopole antenna, transformed into a triple-band antenna for S-band and C-band applications is reported in this paper. This transformation is done with the help of two different hybrid SRR unit cells, which are embedded on the truncated ground plane of the antenna. These hybrid SRR unit cells are created by combining square split ring and circular split ring into two different configurations. Simulated results are in coherence with the measured results and analysis is provided to evaluate the efficacy of the design. This analysis can be used to estimate the usefulness of metamaterial unit cells in generating multiple frequency bands. The operating frequency bands measured are 2.72-2.83GHz, 3.54-4.35 GHz, and 4.72-5 GHz respectively. These bands are being used in the mid-band frequency range of 5G communication in many countries. The developed antenna is miniaturized to the size of 0.19λ0 ×0.25λ0 (λ0 is the free space wavelength at 2.72 GHz). Two objectives i.e., miniaturization and multi-banding are fulfilled in a single design. The introduction of different hybrid SRR unit cells at defective ground plane causes multi-banding and resonance of a unit cell at a lower frequency leads to an increase in the effective electrical length of the antenna without increasing its physical size. The metamaterial characteristic of the unit cells is also verified in the article.

A novel miniaturized V-shaped monopole antenna for GSM/WiMAX/WLAN applications

Abstract This paper presents a novel miniaturized triple band V-shaped antenna (VSA). The miniaturization and the triple-band operation are obtained by performing two V-shaped turns on the metallic strip. The proposed antenna is printed on a single FR4 substrate and fed using the coplanar waveguide (CPW) technique. It operates in three frequency bands, [1.6–1.95 GHz], [2.8–4.4 GHz] and [5.4–5.8 GHz], with stable bidirectional radiation patterns in both E- and H-planes. A prototype of the designed antenna is fabricated and tested where the observed good agreement between simulated and experimental results indicates that the proposed structure, having a reasonably compact size of 0 . 0166 λ 0 2 $\text{0}{\text{.}0166\lambda }_{0}^{2}$ , is suitable for GSM [1800 MHz], WiMAX [3.4–3.77 GHz] and WLAN [5.725–5.825 GHz] applications.

A predicting model for three-dimensional crack growth in power-law creeping solids

Creep fracture mechanics has been extensively studied in the past half a century, but the gap between the creep crack-tip asymptotic field and crack growth prediction has not been effectively bridged so far, hindering the development of high temperature damage tolerance design. Here a predicting model is developed for three-dimensional crack growth in power-law creeping solids with the C(t)PC-Tz asymptotic solution being applied to quantify the creep crack growth driving force. The local resistance for creep crack growth in three-dimensional cracked structures is then described and evaluated based on the micro-cavity growth and constraint theories. Validation against forty-four crack growth experimental data for eleven creeping materials with deferent properties and specimen geometries and subjected to different load level in the literature shows that the proposed model can effectively predict the creep crack growth rate and provide the upper and lower limits. In all cases, the predicted crack growth life is within a triple error band around the experimental data. All the needed material parameters can be obtained from tension tests of standard uniaxial round bar specimens. Therefore, the proposed model can bridge the C(t)PC-Tz asymptotic solution with creep crack growth in practical materials and specimens, paving a road to predict damage tolerance of three-dimensional cracked structures at high temperature.

High-performance tri-band graphene plasmonic microstrip patch antenna using superstrate double-face metamaterial for THz communications

Abstract Recently, graphene-patch antennas have been widely used in communication technology, especially in THz applications due to the extraordinary properties of graphene material. Herein, a graphene-based rectangular microstrip patch antenna is designed on an FR4 substrate material (ɛr = 4.3). A single and double-faced superstrate MTM is placed upon the radiating patch for di erent purposes, such as enhancing the overall antenna performance, protecting the patch from environmental jeopardies, and generating a multiband resonance frequency. A single face superstrate triangle SRR unit was used to produce a dual-band frequency at 3.5 and 4.331 THz. The S 11 of the dual-band structure is achieved to be −26.78 dB and −46.25 dB with a bandwidth of 400 GHz and 460 GHz, respectively. The double face superstrate MTM unit cell of the triangle SRR printed on the opposite face gives another resonant frequency, so, triple frequency bands of 2.32, 3.35, and 4.38 THz with a wide impedance bandwidth of 230, 520, and 610 GHz, were generated, respectively. The double-face superstrate MTM not only enhances the antenna performance but also generates another resonant frequency that could be used in the next 6G communications. The proposed antenna is designed and optimized using two commercial 3D full-wave software, CST Microwave Studio and Ansoft HFSS, to validate the results.

Design of triple band antenna for energy harvesting application

Energy harvesting is a fast-expanding topic in many scientific and engineering-related disciplines due to the extreme necessity to discover answers to the world's power challenges. This paper focuses on the design of a novel antenna that will operate at frequencies of 2.45 GHz, 4.5 GHz, and 5.725 GHz. The study shows the improvement of the current triband antenna for energy harvesting applications by varying the antenna parameters. The return loss, the voltage standing wave ratio (VSWR) and the radiation pattern for the antenna at all frequencies 2.45 GHz, 4.5 GHz, and 5.725 GHz have been compared in the results. The scope of this project development comprises the antenna design utilizing simulation software, computer simulation technology (CST) 2019 and vector network analyzer (VNA) test instrument for physical testing. During the design process, fundamental antenna characteristics were estimated and validated to determine optimal performance of an antenna for this project.

Triple Band Textile Array Antenna with Enhanced Gain and Low SAR for Off Body Communication Applications

A triple band wearable microstrip patch antenna array has been designed and analyzed in this work. The designed antenna can be operated in ISM, LAES and X-Band with moderate average gain of 4.2 dB. The antenna gain has been improved by constructing array structure of 1X2 and 1X4 with good impedance feeding by quarter wave transformer. The proposed array antennas are providing moderate gain of 5.7 dB (1X2) and 8.3 dB (1X4) with efficiency more than 90% in the operating bands. The antenna model and the array has been constructed on wearable substrate with conductive textile as radiating element in the design for off body wearable communication applications. SAR analysis also providing acceptable values below 1.6 w/kg at triple operating bands with body placement experimentation.

Triangular Srr Based Triple Band Amc Backed Antenna for High Gain Sub6ghz Application

This article describes a triple band monopole antenna. t has been assumed that the WiMAX band application is objective. In order to attain the required band, various iterations of the proposed antenna design are carried out. The proposed antenna in the shape of broken hearts operates in the frequency range of 3.2GHz to 4.1GHz. In the final iteration, the heart-shaped double slotted ring resonator (SRR) with two different radii is seen to improve the bandwidth (900MHz) and gain (3dB). In this design, additional parameters like VSWR (approximately 2 at the WiMAX band), impedance (real and imaginary), and efficiency (approximately 89%) have been observed. As a result, the proposed monopole antenna in the shape of a broken heart that operates in the WiMAX band exhibits high efficiency, reduced size, and moderate gain. which play a crucial role in the WIMAX application band.

A Triple Band Circularly Polarized Antenna for Leadless Cardiac Transcatheter Pacing System

The ground-breaking entry of leadless cardiac pacemakers in the cardiac pacemaker’s world has resulted in the design of ultracompact implantable antennas. In this article, we developed a circularly polarized fractal-shaped open-loop antenna for leadless cardiac transcatheter pacing (TCP) system operating at industrial, scientific, and medical bands (915 MHz, 2.4 GHz, and 5.8 GHz). The proposed antenna was constructed on the high permittivity dielectric material Rogers RT/Duroid 6010 LM ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\varepsilon _{r} = 10$ </tex-math></inline-formula> ) with a tiny footprint of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\times 3\times0.254$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . To the best of our knowledge, this is the smallest footprint antenna that works in triple bands with circular polarization, compared with the other reported implantable antennas. We placed the antenna inside the TCP system to evaluate its performance in a realistic environment. Subsequently, it is placed deep inside at the center of the multilayer (skin–fat–muscle) phantom model with dielectric properties equivalent to the human heart. Furthermore, the antenna was integrated into a 3-D printed TCP capsule with dummy electronics for experimental verification, and its performance was checked in the ballistic gel phantom and minced pork. The measured impedance bandwidths of the antenna at 915 MHz, 2.4 GHz, and 5.8 GHz are 580 MHz, 900 MHz, and 1.2 GHz, respectively. Correspondingly, the measured axial ratio bandwidths in phantom are 255 MHz, 260 MHz, and 370 MHz, and measured gain values are −35.1 dBi, −31.6 dBi, and −26.7 dBi.

On the fine spectrum of the operator Q(r,s,t,u) over ℓp and bvp, 1&lt;p&lt;∞

We specify the fine spectrum of the quadruple band matrix operator Q(r,s,t,u) over the sequence spaces ℓp and bvp, where 1<p<∞. The quadruple band matrix Q(r,s,t,u) is the general state of Δ3, D(r,0,0,s), B(r,s,t), Δ2, B(r,s), Δ, right shift and Zweier matrices, where Δ3, B(r,s,t), Δ2, B(r,s) and Δ are called third-order difference, triple band, second-order difference, double band (generalized difference) and difference matrix, respectively.

Design and analysis of novel miniaturised triple band antenna for breast cancer detection

Design and analysis of novel miniaturised triple band antenna for breast cancer detection

EBG and SRR Loaded Triple Band Notched UWB Antenna

A compact triple band notched ultra-wideband (UWB) monopole antenna is presented in this paper. Split Ring Resonator (SRR) structure is exploited in various forms like Complementary Split Ring Resonator (CSRR), Split Ring Resonator Pair (SRRP) and CSRR on Electromagnetic Band Gap (EBG) structure to produce triple band notched characteristics in UWB spectrum. The proposed antenna produces triple band notched functions with integration of all three types of SRR on primary antenna. The parametric analysis of each form of SRR is presented along with their current distribution effects on triple band notched antenna. The proposed antenna prototype is fabricated and measured results are also compared with simulated one to understand the discrepancies. The measured and simulated results are presented to investigate the band notching characteristics of suggested antenna in terms of VSWR and radiation characteristics.

ECG classification system based on multi-domain features approach coupled with least square support vector machine (LS-SVM)

Developing a robust authentication and identification method becomes an urgent demand to protect the integrity of devices data. Although the use of passwords provides an acceptable control and authentication, it has shown much weakness in terms of speed and integrity, which make biometrics the ideal authentication solution. As a result, electrocardiogram (ECG) signals have received a great attention in most authentication systems due to the individualized nature of the ECG signals that make them difficult to counterfeit and ubiquitous. In this paper, we propose a new model for ECG verification using multi-domain features coupled with a least square support vector machine (LS-SVM). Two types of features are investigated to find the best set of features to individual from ECG signals. Time domain and frequency domain features based on optimized Triple Band filter bank are extracted from ECG signals. The extracted features are investigated to figure out the best relevant features and remove the redundant ones. The selected features are fed to three classifiers, including Least Square Support Vector Machine (LS-SVM), K-means, and K-nearest. The obtained results have shown that our ECG biometric authentication system outperforms existing methods. The proposed model obtained an average of accuracy of 88%, 95% with time and frequency features, respectively, while it recorded 99% when a combination of time and frequency features are used to classify ECG signals. A public dataset is used to assess the proposed model.

Photoconductive bowtie dipole antenna incorporating photonic crystal substrate for Terahertz radiation

In this work, a graphene-based Photoconductive bowtie dipole antenna on a photonic crystal substrate is investigated for Terahertz radiation. Basic graphene radiator involving uniform substrate operates at dual bands of 1.4 THz and 1.9 THz with an efficiency of 80% and directivity of 3.3 dBi. Photonic crystal structure is created by implanting periodic arrangement of cylindrical air holes in the Gallium Arsenide (GaAs) substrate to enhance the performance of the basic antenna design. Due to the suppression of surface wave modes by the photonic crystals, additional resonance is created at 2.1THz, making the antenna to operate at triple bands of 1.4 THz, 1.9 THz and 2.1 THz. Opto-electronic simulation is carried out and emission intensity spectrum is also determined for the first time, in a graphene-based terahertz bowtie dipole antenna involving photonic crystals in it. The directivity of the proposed antenna with photonic crystal is found to be 13.7 dBi, which is 10 dB improvement over the conventional design and efficiency of 95% is achieved.

A triple band pattern reconfigurable planar antenna for 5G applications

Abstract This paper presents a triple-band planar antenna with diverse radiation patterns. The proposed planar antenna is a modified swastika shape with three fingers and the ground plane is a circle with rectangular slots etched on four sides radially. The slotted ground plane is loaded with Four PIN diodes to realign the surface current. Pattern reconfigurability is achieved at the triple bands by changing the states of the diode. The antenna operates in triple bands centered at 2.2, 2.9 and 3.5 GHz. The antenna is printed on FR4 Epoxy substrate. The simulated reflection coefficient is well below −10dB at resonant frequencies. The measured patterns and return loss are in very close agreement with the simulated results. This antenna can find potential applications in 5G systems.

Wide bandwidth enriched symmetric hexagonal split ring resonator based triple band negative permittivity metamaterial for satellite and Wi-Fi applications

Bandwidth is a vital factor for the transmission phase of satellite data that plays an important role in satellite performance. This paper presents a wide bandwidth enriched metamaterial consisting of symmetric hexagonal split ring resonator (SRR) with triple band negative permittivity and refractive index and near zero permeability for satellite and Wi-Fi applications. The electrical dimension of the designed metamaterial unit cell is 0.17λ × 0.17λ where wavelength (λ) is computed at a first resonance frequency and developed on a cheap dielectric material FR-4 (lossy) with a thickness of 1.6 mm. The proposed metamaterial contributes triple resonances for the transmission coefficient (S21) at the frequencies of 5 GHz, 6.88 GHz and 8.429 GHz with the magnitude of −33.79, −21.7 and −25.18 dB, respectively covering C and X bands through the numerical execution of CST microwave studio 2019. The effective bandwidth of the unit cell are 1.67 GHz (3.89 to 5.56 GHz), 0.52 GHz (6.59 to 7.11 GHz) and 0.98 GHz (7.98 to 8.96 GHz) where the value of S21 less than −10 dB. The first resonance frequency is used to high speed-bandwidth enriched Wi-Fi and satellite band. Wi-Fi is usually faster using 5 GHz frequency band. The rest of the resonance frequency can be used in satellite applications. A negative permittivity has been perceived at frequencies of 5 – 6.066 GHz, 6.88 – 7.409 GHz, 8.429 – 10.061 GHz using Nicolson-Ross-Weir (NRW) methods with MATLAB code. The dependence of the resonance frequencies on the design parameters, substrate thickness, dielectric materials, the influence of the different structure of unit cell has also been examined. The designed unit cell structure with equivalent circuit diagram are analyzed and validated using Advanced Design System (ADS) simulator that exhibits similar to the S21 of the proposed structure. Furthermore, measurement results and Ansys high-frequency structure simulator (HFSS) simulator results are also employed to verify the outcome. Due to the overall performance, such as wide bandwidth, excellent effective parameters of the designed structure, the proposed research can be very suitable for satellite and Wi-Fi applications.