Multi Band Research Articles

Impact of the reconfigurable optical add-drop multiplexer architecture on the design of multi-band C+L+S optical networks

The main advantage of multi-band (MB) networks is to provide more capacity than C-band networks by using other unused bands like the L- and S-bands and, in this way, postpone the announced optical network capacity crunch. However, MB nodes have a more complex structure than C-band nodes, impacting their cost and enhancing their induced physical layer impairments (PLIs). The main goal of this paper is to analyze the impact of several MB node architectures (namely baseline, common-band and compact MB node architectures) on the total network capacity and total network cost-per-bit, using a routing, modulation format, and spectrum assignment (RMSA) network planning tool based on a Monte–Carlo simulation that also incorporates the impact of network PLIs. When the PLIs are neglected, the common-band architecture presents the lowest cost-per-bit compared to the remaining MB architectures, since only lower cost C-band components are used. However, with the PLIs impact, the common-band architecture leads to the lowest total network capacity and highest cost-per-bit due to additional noise coming from all-optical wavelength converters. In particular, the common-band total network capacity is less than half the baseline and compact total network capacities for a blocking probability of 1%, considering the best channel launch power. Also, the common-band cost-per-bit is almost twice the baseline and compact cost-per-bit due to the PLIs-induced degradation.

High Directivity Microstrip Patch Antenna design using Binary Ebola Search Optimization for Radio Frequency Identification Application

Microstrip patch antenna has gained significant popularity in wireless communication field, because of its compact size, less profile, and ease of installation. It is widely used in various applications such as Radio-Frequency Identification (RFID) systems, where dependable and long-range communication is made possible by the great directivity and efficiency. In this manuscript, a High Directivity Microstrip Patch Antenna design using Binary Ebola Search Optimization for Radio Frequency Identification Application (MPA-RFID-BESO) is proposed.The design of microstrip patch antennas is the difficulty in achieving high directivity while maintaining compact size and low profile. This research explains design and application-specific optimisation of the Microstrip Patch Antenna (MPA) of biomedical utilizing Binary Ebola Search optimization (BESO) algorithm. Microstrip patch antenna is designed to function in double and multi band applications due to its low cost, light weight, and ease of installation. MPA is made with flawed ground construction to lessen cross-polarized radiation emitted by microstrip patches and to achieve the necessary radiation parameters. Here, the cost of the materials is reduced by using a liquid crystal polymer substrate, and aerial performance is enhanced by using the appropriate geometrical parameters. The small design of the BESO optimised improves the performance of antenna as 50mm×50mm compact size. The MATLAB program uses high frequency to do the simulation method. The proposed antenna design is a preferable option for applications involving Radio Frequency Identification (RFID). The performance metrics, such as radiation pattern, constant gain, directivity, bandwidth, and antenna efficiency and return loss are measured and compared to the existing techniques. The proposed MPA-BA-BESO design provides 10.51%, 12.85% and 16.04% higher bandwidth and 23.63%, 47.86% and 32.06% higher gain compared with existing designs, like Designing MPA utilizing Moth–Flame optimization approach (MPA-UWB-MFOA), Predicting Rectangular Patch Microstrip Antenna Dimension utilizing Machine Learning (MPA-ANN), Dual Band Antenna Design and Prediction of Resonance Frequency Utilizing Machine Learning Algorithms (DBAD-RF-CNN) respectively. The proposed technology serve as a better design alternative for microstrip patch antennas in communication systems to address biological applications.

A SIMPLE STRUCTURED MULTIBAND TERAHERTZ METAMATERIAL ABSORBER WITH A HIGH Q FACTOR

A terahertz Eight-/Nine-/Twelve-/Fourteen-/Sixteen-Band Metamaterial Absorber (MMA) for sensing applications is built and simulated. The substrate is sandwiched between the bottom ground plane and the top patch structure of this primitive MMA. The top patch is made up of two concentric circular ring resonators. This structure generates a multiple number of multi bands without utilising stacked layers, multiple resonators, or overlapping in a single unit cell by altering the radius of the top patch structure within the shorter frequency range of 0.8 THz to 1.2 THz. The polarisation and angle insensitivity properties are investigated by shifting the angle values from 0 to 90 degrees. To learn about the inside mechanism of the planned structure, the magnetic field distribution, electric field distribution and surface current distribution plots are explained. For the sixteen-band MMA, the Q-Factor and full width half maximum are also determined. This proposed MMA will be used in biosensing applications, sensors and wireless communications.

Accelerated IVIM-corrected DTI in acute hamstring injury: towards a clinically feasible acquisition time

BackgroundIntravoxel incoherent motion (IVIM)-corrected diffusion tensor imaging (DTI) potentially enhances return-to-play (RTP) prediction after hamstring injuries. However, the long scan times hamper clinical implementation. We assessed accelerated IVIM-corrected DTI approaches in acute hamstring injuries and explore the sensitivity of the perfusion fraction (f) to acute muscle damage.MethodsAthletes with acute hamstring injury received DTI scans of both thighs < 7 days after injury and at RTP. For a subset, DTI scans were repeated with multiband (MB) acceleration. Data from standard and MB-accelerated scans were fitted with standard and accelerated IVIM-corrected DTI approach using high b-values only. Segmentations of the injury and contralateral healthy muscles were contoured. The fitting methods as well as the standard and MB-accelerated scan were compared using linear regression analysis. For sensitivity to injury, Δ(injured minus healthy) DTI parameters between the methods and the differences between injured and healthy muscles were compared (Wilcoxon signed-rank test).ResultsThe baseline dataset consisted of 109 athletes (16 with MB acceleration); 64 of them received an RTP scan (8 with MB acceleration). Linear regression of the standard and high-b DTI fitting showed excellent agreement. With both fitting methods, standard and MB-accelerated scans were comparable. Δ(injured minus healthy) was similar between standard and accelerated methods. For all methods, all IVIM-DTI parameters except f were significantly different between injured and healthy muscles.ConclusionsHigh-b DTI fitting with MB acceleration reduced the scan time from 11:08 to 3:40 min:s while maintaining sensitivity to hamstring injuries; f was not different between healthy and injured muscles.Relevance statementThe accelerated IVIM-corrected DTI protocol, using fewer b-values and MB acceleration, reduced the scan time to under 4 min without affecting the sensitivity of the quantitative outcome parameters to hamstring injuries. This allows for routine clinical monitoring of hamstring injuries, which could directly benefit injury treatment and monitoring.Key points• Combining high-b DTI-fitting and multiband-acceleration dramatically reduced by two thirds the scan time.• The accelerated IVIM-corrected DTI approaches maintained the sensitivity to hamstring injuries.• The IVIM-derived perfusion fraction was not sensitive to hamstring injuries.Graphical

Power-aware high-capacity elastic optical networks

The power consumption of telecommunication equipment has been identified as a relevant contributor to global energy consumption. In fact, new-generation optical transponders employ power-intensive electronic application-specific integrated circuits (ASICs) for digital signal processing (DSP). DSP design has traditionally prioritized meeting transmission requirements over power consumption optimization. In general, the evolutions of transmission techniques and network design have always been mainly driven by traffic increase; in this context, in order to operate network resources more efficiently, margin reduction has been investigated in the past few years. Indeed, traditionally, high physical layer margins are used to ensure reliability over an extended period, resulting in overprovisioning the optical connections for both physical layer conditions and capacity. On the other hand, super-channels have emerged as a suitable solution for accommodating the continuous traffic growth. However, power consumption has not been deeply considered in the optimization of super-channel transmission. This paper first investigates the power efficiency of super-channels operated with designed and reduced margins. Low-margin operation is enabled by adapting sub-carrier spacing and filter bandwidth. Power-aware super-channel optimization is then experimentally demonstrated leveraging a 600 Gbit/s transponder in the SDN-controlled elastic optical network (EON). The results have identified a trade-off between power consumption and spectrum efficiency. Furthermore, the ongoing bandwidth demand has motivated the investigation of multi-band (MB) transmission for scaling the capacity of the existing infrastructures. However, novel networking devices (e.g., optical amplifiers operating beyond the C- and L-bands) will affect the overall power consumption. In this context, experimental power analysis of a thulium doped fiber amplifier (TDFA) is performed based on the traffic load and corresponding configuration. The results show that TDFA power consumption varies with configuration and increases with output power.

Amplifiers in Multi–Band Scenarios—Output Power Requirements, Control and Performance Characteristics

Amplifiers in Multi–Band Scenarios—Output Power Requirements, Control and Performance Characteristics

Yansıma Modunda Doğrusal ve Dairesel Polarizasyon için Çok Fonksiyonlu Çok Bantlı Metasurface

A new metasurface design is presented in multi and broad frequency bands. Metasurface has been designed on Roger 5880 substrate with a thickness of 1.575 mm. The top of the designed metasurface consists of two diagonal mirror m-shaped unit cells. The background plane covers the whole metasurface. Numerical results demonstrate the metasurface's capability for both linear (12.48-13.62 GHz, 19.00-27.64 GHz, 39.45-41.72 GHz, 44.68-45.18 GHz, and 47.52-48.28 GHz) and circular (11.5-12.07 GHz, 30.01-37.77 GHz, 42.3-44.2 GHz, 45.45-47.1 GHz, 48.7-49.54 GHz) polarization conversion with over 90% efficiency. At the same time, the metasurface has good angular stability up 45^0.

Multi band square-shaped polarization-insensitive graphene-based perfect absorber

Multi band square-shaped polarization-insensitive graphene-based perfect absorber

Multi band multi polarised fractal antenna for white space TV band

ABSTRACT Designing a fractal antenna for white space TV band frequencies is the main goal of the suggested work. In this design 4 iteration Koch snowflakes patch is used to get multiband. As the number of iterations increased size of the antenna is going to reduce. Further 4th iteration Koch snowflakes slots have been created in the patch. By introducing a fourth iteration cross slot into the ground plane, three bands have been created. Circular polarisation is attained through the incorporation of cross slots in the ground plane, inducing a phase shift between vertically and horizontally polarised electromagnetic waves. The antenna primarily operates within the last frequency bands (686–806 MHz) with linear polarisation. However, it can also function in the initial frequency band (487–540 MHz) with left-hand circular polarisation. The physical size if antenna is reduced by 38 mm with a gain of 4.5dBi. Axial ratio bandwidth (481–552 MHz) is 71 MHz. Axial ratio bandwidth is 18 MHz more as compared to impedance bandwidth. The same antenna can work in linear polarisation as well as circular polarisation. Multi-polarised, multiband antenna with impedance bandwidth of 10.3% (1st band) and 16.08% (last band) is designed for white space TV band frequencies.

Narrow band absorption and sensing properties of single-walled carbon nanotubes at terahertz metasurface

Due to their excellent electrical and optical properties, carbon nanotubes have unique application prospects in the field of optoelectronics. In this work the vacuum self-assembly method is used to obtain an isotropic single-walled carbon nanotube film with a thickness of 2 μm by the dispersion of single-walled carbon nanotube powder through vacuum filtration; on the basis of extracting the dielectric parameters of the thin film in a range from 0.4 to 2.0 THz, a novel terahertz metasurface narrowband absorber based on single-walled carbon nanotube films is designed and prepared. This metasurface absorber is composed of square and I-shaped narrow slot resonators. The experimental and simulation results show that the proposed terahertz metasurface absorber exhibits four distinct resonance absorption peaks at 0.65, 0.85, 1.16, and 1.31 THz, respectively, achieving a perfect absorption of up to 90%. The absorption mechanism of this novel multi band terahertz metasurface is elucidated by using the theory of multiple reflection interference. By setting analytical layers with different refractive indices on the surface of metasurface device, the sensing performance of metasurface acting as refractive index sensor is studied in depth. The research results indicate that this new type of metasurface absorber has high sensitivity for refractive index sensing, providing new ideas and solutions for further developing carbon-based new terahertz metasurface absorbers.

The Multiband over Spatial Division Multiplexing Sliceable Transceiver for Future Optical Networks

In the last 15 years, global data traffic has been doubling approximately every 2–3 years, and there is a strong indication that this pattern will persist. Hence, also driven by the emergence of new applications and services expected within the 6G era, new transmission systems and technologies should be investigated to enhance network capacity and achieve increased bandwidth, improved spectral efficiency, and greater flexibility to effectively accommodate all the expected data traffic. In this paper, an innovative transmission solution based on multiband (MB) over spatial division multiplexing (SDM) sliceable bandwidth/bitrate variable transceiver (S-BVT) is implemented and assessed in relation to the provision of sustainable capacity scaling. MB transmission (S+C+L) over 25.4 km of 19-cores multicore fibre (MCF) is experimentally assessed and demonstrated achieving an aggregated capacity of 119.1 Gb/s at 4.62×10−3 bit error rate (BER). The proposed modular sliceable transceiver architecture arises as a suitable option towards achieving 500 Tb/s per fibre transmission, by further enabling more slices covering all the available S+C+L spectra and the 19 cores of the MCF.

High modulation laser systems integrated with hybrid pulse generators for high speed fiber transmission systems

Abstract This study has simulated the high modulation laser systems integrated with hybrid pulse generators for high speed fiber transmission systems. The directly modulated laser with raised cosine/Gaussian pulse generators are employed for ultra-high data rates for modified multi band range applications. The total estimated light power after fiber cable system is demonstrated based on electro-absorption, phase, and single drive MZM measured modulators. The light base band signal and noise signal configuration is clarified after fiber cable system based on various proposed modulators. The degree of signal polarization configuration is studied after fiber cable system based on various modulators. Signal power level with Q, BER, signal eye height, and the total estimated electrical modulated signal power are evaluated after receiver system after receiver side based on proposed modulators.

Network traffic analysis under emerging beyond-5G scenarios for multi-band optical technology adoption

The recently created ITU-T Focus Group Network 2030 is leading network operators to identify the requirements and use cases that networks are expected to fulfill for the short, medium, and long term within the current decade. Essentially, network operators need to evolve their networks to meet strict performance requirements in several dimensions, including a large bandwidth to support foreseen beyond-5G (B5G) services, such as digital twins and volumetric video. To provide such a bandwidth requirement in a sustainable and scalable way, multi-band (MB) optical networks are expected to gradually extend legacy optical network capacity by exploiting bands beyond C+L. In this paper, we present a traffic analysis methodology to help network operators to compute expected traffic demand to be supported in their networks as a result of combining well-known mass market services with foreseen B5G service scenarios. Numerical results based on inputs and forecasts from major European network operators show that MB will be required at all network segments, including metro-aggregation, metro-core, and backbone, by the end of this decade.

Stubs loaded multi band antenna for vehicle-to-vehicle communication

Stubs loaded multi band antenna for vehicle-to-vehicle communication

Coordinated control of multi band PSS (MBPSS) with type 2 fuzzy based SSSC controller design for power system stability improvement

Coordinated control of multi band PSS (MBPSS) with type 2 fuzzy based SSSC controller design for power system stability improvement

Mathematical modelling and simulation of a wideband PLL for application in frequency synthesizers

In this paper the mathematical modelling of the Voltage Controlled Oscillator, Phase Frequency Detector, Low Pass Filter, Charge pump for designing a PLL circuit is proposed. Based on the modelling schematics are designed and proposed for the application in frequency synthesizer. The main design feature of this modelling is that VCO tunning switches are controlled digitally. The behaviour of PLL under its region of operation is simulated. The effect of temperature variations and insufficient bandgap overlapping on the output frequency of PLL is also presented and discussed. To avoid the current mismatching and residual phase errors the charge pump is modelled as to calibrate by its own circuit. Various simulations are done for the performance analysis of wideband PLL. The proposed design will have its application in frequency synthesizers suitable for multi band transceivers.

Optical cable deployment versus fiber leasing: an operator’s perspective on CapEx savings for capacity upgrade in an elastic optical core network

Multiband (MB) and multifiber (MF) technologies get significant attention along with their individual pros and cons to solve the optical fiber capacity crunch problem. The MB system is more susceptible to nonlinear transmission impairments such as interchannel stimulated Raman scattering. On the contrary, MF solutions are costly due to the requirement of parallel fiber deployment. Therefore, it is necessary to find a hybrid solution using MB and MF technologies. This paper performs a techno-economic comparison between MF and MB technologies while taking a robust cost model. We propose, for the first time to our knowledge, a domain-knowledge-assisted, cost-effective network upgrade algorithm to enhance the overall network capacity while including minimum capital expenditure (CapEx). The proposed algorithm prioritizes the targeted deployment of cost-effective upgrade solutions in different links of the network to minimize the overall cost of the upgrade. The comparison between optical cable deployment and fiber leasing is captured to upgrade the overall network capacity with minimum cost-per-bit. Reported results show that a single fiber C+L band system can provide approximately 66.67% gain in terms of traffic admissibility compared to MF C band systems in smaller networks such as BT-UK, while considering fiber leasing. If operator owned dark fibers are not available in any of the links, numerical results show that the MF C+L band system in the BT-UK network can still provide CapEx savings of approximately up to 40.5% compared to the MF C band systems while minimizing the cost-per-bit of the network by approximately 21.9% to achieve the targeted network capacity of 150 Tbps. The effect of longer link length on the network upgrade cost is also studied in this paper. Reported result shows that, for larger geography such as the pan-Europe network, the channel launch power needs to be tuned to achieve the benefit of the MF C+L band compared to the MF C band system.

Source contribution analysis of vehicle pass-by noise using a moving multi-band model based OPAX method

The conventional operational path analysis with eXogeneous inputs (OPAX) method has been widely used to investigate the vibration transfer paths. However, the single degree of freedom model is not available for the load identification of acoustic sources due to their unknown source behavior. And the alternative multi-band (MB) model can only offer a deterministic estimation to the load parameters. To assess the acoustic source contribution of vehicle pass-by noise (PBN), this paper develops the OPAX method by introducing a moving multi-band model (MMB). In this method, the vehicle acoustic sources are simplified as a combination of a series of point sources. The source loads are firstly parametrically modelled by MB models. Then the load parameters are solved several times in the MMB and estimated by the index of coefficient of variation, which suppresses the effect of nonlinear random noise and improves the load identification accuracy of acoustic sources. Finally, the source contributions to PBN at receivers can be derived. Both numerical studies and experimental validations are implemented to examine the performance of the proposed method. Results show that compared to the conventional OPAX method, the proposed method can provide a higher accuracy for the source contribution analysis of PBN.

Preparation of multi band photothermal responsive bio-based superhydrophobic self-healing poly(siloxane-urethane) coating

In order to improve the poor hydrophobicity and single repair conditions of traditional self-healing polyurethane coatings, prepolymers were synthesized with bio-based polyol castor oil (CO), self-made alkyl aryl modified silicone polyols (Si-OH) and isophorone diisocyanate (IPDI), and 4,4'-dithiodianiline (ODD) was used as chain extender containing dynamic disulfide bond, 4-methylumbelliferone (4-MU), as a bio-based end capping agent with reversible ring structure, was polymerized step by step to prepare a photothermal responsive bio-based superhydrophobic self-healing poly(siloxane-urethane) coating (PUSi). In this paper, the effect of the amount of alkyl aryl modified silicone polyol (Si-OH) on the properties of PUSi was studied. The results showed that PUSi with different alkyl aryl modified silicone polyol additions could achieve self-healing under heating, UV irradiation and infrared light irradiation, and the maximum repair efficiency could reach 91% through optical microscope (OM), 3D profilometer and universal testing machine; The contact angle meter proved that the introduction of alkyl aryl modified silicone polyol greatly improved the hydrophobicity of PUSi, and the maximum water contact angle was 162°. The coating has broad application prospects in the fields of self-cleaning fabrics, super hydrophobic surfaces, special protective clothing and so on.

Modelling of GaAsSb/InAs type-II QW heterostructure and simulation of its optical gain characteristics under (100), (001) and (110) directional pressure

A multi band (particularly, six band) k. p approach has been adopted for modelling the GaAsSb/InAs/AlSb W-shaped quantum well (QW)-heterostructure (a type-II with broken bandgap band alignment) and simulation of behaviour of optical gain characteristics under uni- and bi-axial pressures. The motivation behind designing such QW heterostructure is its high optical gain in MIR (mid infrared region) with noteworthy tuneable optical characteristics. The tuneable characteristics under uni-axial (100) and (001) pressure and bi-axial (110) pressure have been studied through the simplification of a multiband band k. p Hamiltonian. For all the directional pressures, the pressure range was fixed from 1 GPa to 3 GPa (with the interval of 0.5 GPa). For the (100) directional pressure, a significant increase in the gain (from 3570 to 7800/cm) was noted showing the red shifted wavelength with increasing order of pressure; while (001) directed pressure has caused to reduce the gain (3550–1158/cm) with red shifted wavelength. The (110) directed pressure has also caused to enhance the gain considerably (2550–7597/cm) with change in wavelength towards high wavelength. The study of gain characteristics was performed considering 1.5 × 1012 cm−2 2-D charge carrier density, which proves the tunability of the designed heterostructure in various tuneable optoelectronic devices.