Big Bandwidth Research Articles

An improved Mini Antenna Designed at 60GHZ for a New Generation Mobile Phone

Five-generation (5G) communication systems are being required to meet the needs of small, high-speed, and big bandwidth systems [2]. This paper simulates and designs a 60GHZ rectangular micro strip patch antenna. The proposed antenna resonates at 60GHZ with a return loss of -32.126 dB, efficiency of 87.7119%, and gain of 6.96485 dBi. The patch is 2.726 x 2.364 x 0.125 mm. The radiating patch and the 50Ω micro strip feed line are matched using an iset feed transmission line approach. A Roger RT Duroid 5880 substrate, with a height of 0.125mm and a dielectric constant of 2.20 and a loss tangent of 0.0009, was selected in the design. The Advanced Design System (ADS) was used to compute the antenna's parameters and evaluate the results of simulations.

Preparation and characterization of electromagnetic wave absorbing material from polymetallic vanadium titano-magnetite (VTM): Oriented phase transformation underlying formation mechanism

Polymetallic vanadium titano-magnetite (VTM) is recognized as one of the most refractory mineral resources because of its multiple-element composite symbiosis feature. Conventional carbothermic reduction and smelting separation treatment are characterized by high energy consumption and large greenhouse gas emissions. Considering the material attribute, an alternative and clean utilization of refractory VTM via the pyrometallurgically oriented phase transformation in air atmosphere to prepare the composite electromagnetic wave absorbing material was proposed for the first time in this work. The theoretical foundation of the oriented composite material design, phase transformation, microstructure and interfacial element migration, magnetism, electromagnetic properties, and wave absorbing properties were investigated via thermodynamic calculations, XRD, XPS, optical microscope, SEM‒EDS, VSM, and VNA analyses. Theoretical calculations indicated that the formation of composite ferrites was thermodynamically feasible over 1085 °C. In the oriented phase reconstruction, the symbiotic structure of the VTM was reconstructed via MnO2 addition at 1150 °C, and almost all the Fe, Mn, Ti, and V were concentrated in the composite ferrites, in which the Ti and V were doped in the octahedral structure (B site) of spinel-type crystalline structure. The as-purified composite ferrite material from the VTM+80%MnO2 mixture roasted at 1150 °C for 2 h showed good electromagnetism performance. A minimum RL peak of −50 dB was obtained at a veneer thickness of 11 mm, and the RL value less than −20 dB had a big frequency bandwidth of 9 GHz (frequency range of 8 GHz–17 GHz). It's inferred that this low-cost and abundant composite ferrite material can be economically applied in the construction industry. This work provided a clean and higher-value application of abundant refractory polymetallic VTM resources.

Heterogeneous Big Data Parallel Computing Optimization Model using MPI/OpenMP Hybrid and Sensor Networks

For the heterogeneous big data parallel computing model, two levels of parallelism between nodes are not considered, resulting in low efficiency of heterogeneous big data parallel computing and bandwidth to send and receive information, high communication overhead, long model running time and small computational volume. In the paper, we propose an optimization model of heterogeneous big data parallel computing based on a hybrid Multi Point Interface (MPI)/Open Multi-Processing (OpenMP) and Sensor Networks. First, the processor characteristics of heterogeneous big data architecture is analyzed, the parallel tasks among processors are divided, collect the heterogeneous big data to be computed and cluster them, and use the processing results as the input items of the model. Then, a parallel load balancing mechanism is established to optimally divide the parallel computing load of heterogeneous big data, and a parallel computing optimization program is written by combining the hybrid programming mode of MPI and OpenMP and using the hybrid MPI/OpenMP, and finally, the parallel computing optimization of heterogeneous big data is realized by optimizing the parallel communication and determining the model parameters. The results show that the proposed model has a communication bandwidth of 510Mbps, a computational volume of 1.16GB, a model runtime of 24s, and an improved network bandwidth utilization of 93%, which can effectively reduce the communication overhead, and improve the efficiency of parallel computing and bandwidth sending and receiving information in sensor networks, and shorten the model running time.

Architectures, Security Issues, and Usage Scenarios of EC

Demand for the digital media is increasing exponentially due to the data generated with regards to IoT devices, thus for these growing needs certain advancements have been made in various technologies like cloud computing which has transitioned to fog and edge computing. The differences between each technology relate to many factors like security, privacy, Big data issues, bandwidth, and radio access networking. Thus, we have discussed the problems faced by older versions of cloud computing and how Mobile Edge Computing (MEC) helps to overcome most of these problems. MEC is explored where it offers real-time information thus providing benefits to the end-users. The growth of MEC is such that, as discussed further, it is used in normal habitual routines like real-time grocery shopping. This paper explores the various architectures, use cases and security aspects of edge computing.

A Design Method for Labyrinth Sound Absorption Structure with Micro-perforated Plates

A kind of labyrinth sound absorption structure is constructed by embedding multi-layer micro-perforated plates into a pipeline, and a design method is proposed to optimize its parameters to ensure a good sound absorption performance. First, the effects of parameters of the labyrinth structure on the sound absorption performance are investigated. Second, a parameter optimization method is constructed based on the acoustic impedance transfer analysis and particle swarm optimization algorithm. Then, a simulation experiment is implemented by means of COMSOL to verify the optimization results. Finally, the labyrinth structures with straight pipeline, spiral pipeline and parallel pipeline are designed and their sound absorption performances are evaluated and compared. The research shows that, the effects of the perforation diameter, the plate thickness, and the perforation rate on the sound absorption performance are non-independent while the effect of the depth of cavity is independent; the weighting coefficient in the parameter optimization method could be adjusted to ensure a big absorption bandwidth in a low frequency range; in the frequency range of 30-4000 Hz, the labyrinth structure with straight pipeline and the labyrinth structure with spiral pipeline have the same sound absorption performance; for the labyrinth structure with parallel pipeline, the inner corner radius of pipeline has a great influence on the sound absorption performance, and the radius should be greater than 20mm.

A design method of acoustic metamaterials with buckling vibrators

This paper proposes a periodic acoustic metamaterial with buckling vibrators, and investigates the design method for the band-gap characteristics of the acoustic metamaterial. The unit cell of the acoustic metamaterial is constructed by a continuous bar, curved beams embedded into the bar and the mass supported by the curved beams. The band structure of infinite period and the transmission characteristics of finite period are researched to analyze the effect of the structural and material parameters of the curved beam on the band-gap characteristics of the unit cell. And the effect of pre-strains applied to the curved beam on the band-gap characteristics is also discussed. The research illustrates that the acoustic metamaterial with buckling vibrators has a low frequency band-gap of 100-125Hz; in the frequency range of 0-200Hz, the central frequency of the band-gap increases with the increase of the beam width; the curvature radius of the beam has little influence on the central frequency of the band-gap, and a big bandwidth of the first band-gap can be obtained when the curvature radius is 20 mm; by applying pre-strain to the curved beam in a certain extent, the central frequency of the band-gap can be effectively reduced, and the attenuation more than 100 dB can be guaranteed.

Locality-Aware GPU Register File

In many emerging applications such as deep learning, large data set is essential to generate reliable solutions. In these big data workloads, memory latency and bandwidth are the main performance bottlenecks. In this article, we propose a locality-aware GPU register file that enables data sharing for memory-intensive big data workloads on GPUs without relying on small on-chip memories. We exploit two types of data sharing patterns commonly found from the big data workloads and have warps opportunistically share data in physical registers instead of issuing memory loads separately and storing the same data redundantly in their registers as well as small shared memory. With an extended register file mapping mechanism, our proposed design enables warps to share data by simply mapping to the same physical registers or reconstructing from the data in the register file already. The proposed sharing not only reduces the memory transactions but also further decreases the register file usage. The spared registers make rooms for applying orthogonal optimizations for energy and performance improvement. Our evaluation on two deep learning workloads and matrixMul show that the proposed locality-aware GPU register file achieves over 2× speedup and saves register space up to 57 percent.

Stochastic Responses for the Vibro‐Impact System under the Broadband Noise

The stochastic averaging is applied to derive the random responses of the SDOF vibro‐impact system with one‐side wall under additive and multiplicative broadband noise, where the impact is described by the modified Hertzian contact model. Compared with the popular simplified “classical model” (i.e., ), the whole impact process is captured by the modified Hertzian contact model without any assumptions. One example is given to illustrate the proposed technique. The comparison between the analytical results and those from Monte Carlo simulations manifests the accuracy of the proposed technique. It should be pointed out that the technique proposed in this paper is powerful for the cases of weak excitation and big enough bandwidth of the broadband noise. Finally, the influences of various parameters are also discussed in detail.

The Operational Issue of an Airliner’s Reduced-Crew Caused by Data-link Break-up to Remote Support

Different operational concepts for Single-Pilot and Reduced-Crew Operations (RCO) in commercial aviation include a ground based supportive component of a remote-copilot. The impact of an outage and break-up of the data-link connecting air and ground has not been investigated yet. Social Network Analysis (SNA) in combination with a Cognitive Work Analysis was used to compare the three crewing options of multi-crew, reduced-crew and a break-up of data-link in RCO in terms of social factors and interactions. A data-link loss decreased the networks density and its resilience to any off-nominal and emergency situations. The single-pilot suffers from higher functional loadings, is located more central and processes a higher information flow. A twofold degraded operational procedure was proposed to mitigate an outage and loss of data-link in combination with additional automation tools onboard. Nonetheless, further research is required to provide a data-link with a big bandwidth as reliable and secure as possible.

A Survey on C-RAN Security

While 4G is speeding up its steps toward global markets, 5G has initiated its full development to satisfy an increasing demand on mobile data traffic and big data bandwidth. Centralized data processing, collaborative radio, real-time cloud infrastructure, and cloud radio access network (C-RAN), along with their excellent advantages are being sought by more and more operators to meet end-user requirements. As a promising mobile wireless network architecture, compared with traditional RAN, C-RAN has incomparable advantages in terms of low power consumption, reduced base station (BS) numbers, and economic capital and operating expenditure. It can also improve network capacity and BS utilization rate. Recently, C-RAN security has aroused special attention and concern. However, the literature still lacks an overall review on it in order to guide current and future research. In this paper, we first overview the architecture, deployment scenarios, and special characteristics of C-RAN. We then provide a thorough review on the existing security studies in the field of C-RAN based on its three logic layers and corresponding security threats and attacks. Particularly, we discuss whether the current literature can satisfy the expected security requirements in C-RAN. Based on this, we indicate open research issues and propose future research trends.

THE ABSORPTION AND CONDUCTIVITY FOR MICROSTRUCTURED SILICON IN THE IMPURITY-DEFECT MODEL

In this paper, a model for the optical absorption and carrier concentration in microstructured silicon is presented based on Gaussian energy distribution of defect and impurity, as well as the Boltzmann distribution of carriers. The parameters of the impurity and defect model contributing to the absorption and carrier concentration are investigated. The simulation results show that the absorption in the single level impurity-defect model ranges from 64% to 68%; larger than that in the single level impurity model (55%–65%); as well as that in the defect model (50%–66%). It also indicates that the absorption increases with bigger correlation energy (U) and the best bandwidth (d) is 0.92 eV. However, the carrier concentration gets stronger with bigger bandwidth, smaller correlation energy and higher temperature. Thus, these calculations would play an important role in the applications of microstructured silicon.

Low-Loss Hand-Made Demultiplexer using Transparent Color Filter in WDM-POF Network for Short-Haul Communication System

Problem statement: Polymer optical fiber has advantages compared to other alternatives communication media such as copper, coax cable and glass fiber. POF has bigger bandwidth compared to wireless communication network and POF is also free from electromagnetic disruption. Since POF is suitable for communication system up to distance of 100 m with data speed of 400 Mbps using polymer step-index type, therefore, POF is effective for short haul data transmission. Application of POF includes the Ethernet network at home or usually known as Fiber To The Home (FTTH) and in also used in automotive system. However, since the demand of high capacity of the transmission system, wavelength division multiplexing technique or WDM is applied in this study. Approach: Several signals with different wavelengths are multiplexed and carried over a single fiber and demultiplexed at the end of the communication system to obtain the original signal to be directed to the receiver. The advantage of the device developed in this study is that it is easy to construct and inexpensive. Thin-film is used as filter and three main color wavelength used are red, blue and green thin-films. The red thin-film will absorb any other wavelength other than λ = 650 nm, blue thin-film will absorb any other wavelength other than λ = 475 nm while the green thin-film will absorb any other wavelength that is not around λ = 510 nm. Characterization is done to test the signal loss through each of the thin-film. Low-loss filter for the wavelength of the desired signal is analyzed to get the best thin-film that gives optimum transmission while blocking other undesired wavelengths. Insertion loss and power output are measured to determine the thin-film to develop the demultiplexer that work effectively. In this study, the distance of the optical fiber is not taken into account, however, the length of the optical fiber is set to be 5 m each. Results: Although there exists attenuation of signal transmission along the fiber and at the transparent colored thin-film, the demultiplexer works efficiently for short haul communication system with small loss of power output and small increase of insertion loss for the desired wavelength transmitted. Conclusion: Analysis shows that the device works efficiently for short distance communication although the results show insignificant signal loss along the transmission.

The Design and Research of Switching Power Amplifier Used on Magnetic Suspension Support

This paper focuses on the switching power amplifier of magnetic suspension support. The principle of magnetic suspension support was described. Due to the particularity that the load of magnetic suspension support is inductive, the response speed, efficiency and stability should be considered when the switching power amplifier is designed. In the power amplifier, PI circuit can make feedback current follow the given signal in time. In this paper, the amplifier adopts pulse width modulation (PWM) control strategy. The design of PI circuit, PWM circuit as well as the driving circuit were presented in the paper. After completing the designs of all parts, we choose MULTISIM as simulation software, which can establish an accurate circuit model. The simulation results show that the switching power amplifier designed in this paper has bigger bandwidth and less distortion and it can respond timely.

Two kinds of tension in fiber Bragg gratings with cladding etched as the sinusoidal function

A new grating structure with cladding etched as the sinusoidal function along the length direction is introduced. The cladding area of the grating varies as the sinusoidal function along fiber axes. The coupled mode theory is used to analyze its performance. Compared with the linearly chirped grating, the new structure exhibits an ideal box spectrum with steep edges when the tension is applied on the gratings in two different ways. For the type B grating, without tension after writing, it has a bigger bandwidth utilization (BWU) than that of the type A grating with tension after writing. Compared with the type A grating, the type B one is more adaptable in fiber-optic communications and sensor systems.

Orchestra – small system with big bandwidth

Orchestra – small system with big bandwidth