scholarly journals A Micro-Scaled Graphene Based Tree-Shaped Wideband Printed MIMO Antenna For Terahertz Applications

2021 ◽  
Author(s):  
K. Vasu Babu ◽  
Sudipta Das ◽  
Gaurav Varshney ◽  
Gorre Naga Jyothi S ◽  
Boddapati Taraka Phani Madhav
Keyword(s):  
Resonant Frequency ◽  
High Speed ◽  
Chemical Potential ◽  
Surface Current ◽  
Design Parameters ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Design Evolution ◽  
Terahertz Applications ◽  
Distance Communication

Abstract A tree-shaped graphene based microstrip MIMO antenna for terahertz applications is proposed. The proposed MIMO antenna is designed on a 600×300 µm2 polyimide substrate. The designed MIMO antenna exhibits a wide impedance bandwidth of 88.14% (0.276–0.711 THz) due to the suggested modifications in the antenna configuration. The MIMO design parameters like total active reflection coefficient (TARC), mean effective gain (MEG), envelope correlation coefficient (ECC) and diversity gain (DG), Channel capacity loss (CCL) are evaluated and their values are found within acceptable limits. The proposed MIMO structure offers MEG ≤ -3.0 dB, TARC≤ -10.0 dB, DG≈ 10 dB, CCL < 0.5 bps/Hz/sec and ECC < 0.01 at the resonant frequency. At the resonant frequency, the isolation between the radiating elements of the proposed MIMO is recorded as -52 dB. The variations in operating frequency and S-parameters are also analyzed as a function of the chemical potential (µc) of the graphene material. The parametric analysis, structural design evolution steps, surface current distribution, antenna characteristics parameters and diversity parameters are discussed in detail in this paper. The designed MIMO antenna is suitable for high speed short distance communication, video rate imaging, biomedical imaging, sensing, and security scanning in the THz frequency band.

Stress and Vibration Analysis of Motor Back Plate in HDD

2011 ◽  
Vol 275 ◽  
pp. 97-100 ◽  
Author(s):  
Geun Sub Heo ◽  
Oh Hyun Kang ◽  
Cheol Woo Park ◽  
Sang Ryong Lee ◽  
Choon Young Lee
Keyword(s):  
Resonant Frequency ◽  
High Speed ◽  
Vibration Mode ◽  
Hard Disk Drives ◽  
Mode Analysis ◽  
Design Parameters ◽  
Disk Drives ◽  
Ansys Software ◽  
Back Plate ◽  
Plate Shape

In the present study, we have simulated stress characteristics and vibration modes in the back plate of head-stack driving motor of 2.5 inch small sized hard disk drives (HDDs). The magnets in head-stack driving motor have large magnetic fields, and therefore, the resulting large force may induce fracture and deformation in the back plate of the motor. Since the high-speed motion of head-stack motor generates high frequency vibration, we analyzed the vibration mode to avoid resonant frequency. ANSYS software was used in this study to check the deformation of back plate with the following design parameters: thickness of plate, the number of support beams, and the width of support beams. From the vibration mode analysis, we obtained a stable plate shape whose operating frequency is off the resonant frequency.

Design of a compact MIMO antenna system with reduced mutual coupling

2014 ◽  
Vol 8 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Mohammed Younus Talha ◽  
Kamili Jagadeesh Babu ◽  
Rabah W. Aldhaheri
Keyword(s):  
Resonant Frequency ◽  
Mutual Coupling ◽  
Mimo System ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Antenna System ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Operating Band

A novel compact multiple-input–multiple-output (MIMO) antenna system operating from 5 to 7.3 GHz is proposed for wireless applications. It comprises of two similar antennas with microstrip feeding and radiating patches developed on a reduced ground plane. The developed antenna system resonates at a dual-band of 5.4 and 6.8 GHz frequencies, giving an impedance bandwidth of 38% (based on S11 < −10 dB). The unique structure of the proposed MIMO system gives a reduced mutual coupling of −27 dB at 5.4 GHz resonant frequency and −19 dB at 6.8 GHz resonant frequency and in the entire operating band the coupling is maintained well below −16 dB. The envelope correlation coefficient of the proposed MIMO system is calculated and is found to be less than 0.05 in the operating band. The measured and simulation results are found in good agreement.

scholarly journals Design Issues and Challenges in Indoor MIMO Antenna Systems

2020 ◽  
Vol 8 (6) ◽  
pp. 3842-3846
Keyword(s):  
High Speed ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Research Work ◽  
Antenna System ◽  
Design Parameters ◽  
Future Research ◽  
Design Issues ◽  
Mimo Antenna

The promising solution for next generation wireless communication system is multiple input multiple output (MIMO) system. It can transmit and receive data from different channels simultaneously without any need of additional frequency band. In this paper the design issues and challenges in MIMO antenna system for different applications have been reviewed. The major applications of MIMO systems include Wi-Fi, High Speed Packet Access, LTE, WiMAX (4G), and also MIMO has been used in power line communication. Implementation of MIMO antenna system is dependent on important parameters such as: Peak gain, Average Gain, Mutual Coupling, Envelop Correlation Coefficient (ECC), Total Active Reflection Coefficient (TARC), Signal polarization and Miniaturization of antenna system. Hence an optimal MIMO antenna design to suit for communication applications in an indoor environment is a challenging task. This paper proposes comparative study for the different MIMO antenna parameters. The different modeling techniques for MIMO antenna system are surveyed and areas for future research work in line with tradeoffs between different design parameters are suggested.

scholarly journals A Wider Impedance Bandwidth Dual Filter Symmetrical MIMO Antenna for High-Speed Wideband Wireless Applications

Symmetry ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 29
Author(s):  
Manish Sharma ◽  
Prem Chand Vashist ◽  
Ibrahim Alsukayti ◽  
Nitin Goyal ◽  
Divya Anand ◽  
...  
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Impedance Bandwidth ◽  
Area Network ◽  
Rectangular Slot ◽  
Mimo Antenna ◽  
Wireless Applications ◽  
Radiating Element

This research article reports a compact fractal 4 × 4 UWB extended bandwidth MIMO antenna with physical dimensions of 44 × 44 mm2 for high-speed wireless applications. The reported antenna comprises four fractal radiating elements that are symmetrical and placed orthogonal to each other with a respective rectangular ground printed on the opposite plane. A higher isolation is achieved between the radiating elements by the placement of a fractal patch orthogonally and no separate decoupling structure is required. The antenna offers a −10 dB transmission capacity of 2.84–15.88 GHz. The fractal radiating element, which is embedded by an inverted T-type stub placed within a rectangular slot and an etched rotated C-type slot, provides band-stop filters for WiMAX (Worldwide inter-operability for Microwave Access) and WLAN (wireless local area network)-interfering bands. The key parameters of diversity performance are compared by simulation and measurement (fabricated prototype) of ECC (envelope correlation coefficient), DG (directive gain), TARC (total active reflection coefficient) and CCL (channel capacity loss). The antenna offers an omnidirectional radiation pattern with an average gain of 3.52 dBi.

A compact four-port UWB MIMO antenna with connected ground and wide axial ratio bandwidth

2019 ◽  
Vol 12 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Sachin Kumar ◽  
Gwan Hui Lee ◽  
Dong Hwi Kim ◽  
Wahab Mohyuddin ◽  
Hyun Chul Choi ◽  
...  
Keyword(s):  
Design Method ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Axial Ratio ◽  
Unit Cell ◽  
Ultra Wideband ◽  
Design Parameters ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Input Multiple Output

AbstractA new design method of an ultra-wideband circularly-polarized planar multiple-input-multiple-output (MIMO) antenna is presented in this paper. The proposed MIMO antenna consists of four unit cell antennas, being comprised of a microstrip feed line and a square slotted ground plane. In the proposed unit cell design, a circular stub is protruded from the ground plane strip for achieving circular polarization. The unit cell of the MIMO antenna is optimized by adjusting design parameters. The compact four-port MIMO antenna prototype is designed on the FR4 substrate with the overall dimensions of 45 × 45 × 1.6 mm3. The proposed four-port MIMO antenna design provides an impedance bandwidth (S11 < −10 dB) of 112% (3.1–11 GHz) and a 3 dB axial ratio bandwidth of 36% (4.8–6.9 GHz). The performance of the fabricated MIMO antenna shows good agreement between the EM simulation and measurement results.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

The Engagement of Hybrid Ultra High Space Division Multiplexing with Maximum Time Division Multiplexing Techniques for High-Speed Single-Mode Fiber Cable Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
P. G. Kuppusamy ◽  
Ahmed Nabih Zaki Rashed ◽  
P. Jayarajan ◽  
M. R. Thiyagupriyadharsan ◽  
...  
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Design Parameters ◽  
Control Parameters ◽  
Data Rates ◽  
Fiber Optic Communication ◽  
High Space ◽  
Optic Communication

AbstractHigh-speed single-mode fiber-optic communication systems have been presented based on various hybrid multiplexing schemes. Refractive index step and silica-doped germanium percentage parameters are also preserved during their technological boundaries of attention. It is noticed that the connect design parameters suffer more nonlinearity with the number of connects. Two different propagation techniques have been used to investigate the transmitted data rates as a criterion to enhance system performance. The first technique is soliton propagation, where the control parameters lead to equilibrium between the pulse spreading due to dispersion and the pulse shrinking because of nonlinearity. The second technique is the MTDM technique where the parameters are adjusted to lead to minimum dispersion. Two cases are investigated: no dispersion cancellation and dispersion cancellation. The investigations are conducted over an enormous range of the set of control parameters. Thermal effects are considered through three basic quantities, namely the transmission data rates, the dispersion characteristics, and the spectral losses.

Parameter study and optimization design of a hat oblique tunnel portal

2021 ◽  
pp. 095440972110140
Author(s):  
Zijian Guo ◽  
Tanghong Liu ◽  
Wenhui Li ◽  
Yutao Xia
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Pareto Front ◽  
Optimization Problem ◽  
Optimization Method ◽  
Design Parameters ◽  
Parameter Study ◽  
Buffer Structure ◽  
Tunnel Entrance ◽  
The Ideal

The present work focuses on the aerodynamic problems resulting from a high-speed train (HST) passing through a tunnel. Numerical simulations were employed to obtain the numerical results, and they were verified by a moving-model test. Two responses, [Formula: see text] (coefficient of the peak-to-peak pressure of a single fluctuation) and[Formula: see text] (pressure value of micro-pressure wave), were studied with regard to the three building parameters of the portal-hat buffer structure of the tunnel entrance and exit. The MOPSO (multi-objective particle swarm optimization) method was employed to solve the optimization problem in order to find the minimum [Formula: see text] and[Formula: see text]. Results showed that the effects of the three design parameters on [Formula: see text] were not monotonous, and the influences of[Formula: see text] (the oblique angle of the portal) and [Formula: see text] (the height of the hat structure) were more significant than that of[Formula: see text] (the angle between the vertical line of the portal and the hat). Monotonically decreasing responses were found in [Formula: see text] for [Formula: see text] and[Formula: see text]. The Pareto front of [Formula: see text] and[Formula: see text]was obtained. The ideal single-objective optimums for each response located at the ends of the Pareto front had values of 1.0560 for [Formula: see text] and 101.8 Pa for[Formula: see text].

scholarly journals Reliability Evaluation of Fan-Out Type 3D Packaging-On-Packaging

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 295
Author(s):  
Pao-Hsiung Wang ◽  
Yu-Wei Huang ◽  
Kuo-Ning Chiang
Keyword(s):  
Finite Element ◽  
Thermal Cycling ◽  
Glass Substrate ◽  
High Speed ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Design Parameters ◽  
Time To Failure ◽  
Wafer Level ◽  
Fine Pitch

The development of fan-out packaging technology for fine-pitch and high-pin-count applications is a hot topic in semiconductor research. To reduce the package footprint and improve system performance, many applications have adopted packaging-on-packaging (PoP) architecture. Given its inherent characteristics, glass is a good material for high-speed transmission applications. Therefore, this study proposes a fan-out wafer-level packaging (FO-WLP) with glass substrate-type PoP. The reliability life of the proposed FO-WLP was evaluated under thermal cycling conditions through finite element simulations and empirical calculations. Considering the simulation processing time and consistency with the experimentally obtained mean time to failure (MTTF) of the packaging, both two- and three-dimensional finite element models were developed with appropriate mechanical theories, and were verified to have similar MTTFs. Next, the FO-WLP structure was optimized by simulating various design parameters. The coefficient of thermal expansion of the glass substrate exerted the strongest effect on the reliability life under thermal cycling loading. In addition, the upper and lower pad thicknesses and the buffer layer thickness significantly affected the reliability life of both the FO-WLP and the FO-WLP-type PoP.

A printed multiband MIMO antenna with decoupling element

2019 ◽  
Vol 11 (4) ◽  
pp. 413-419 ◽  
Author(s):  
Ziyu Xu ◽  
Qisheng Zhang ◽  
Linyan Guo
Keyword(s):  
Mutual Coupling ◽  
Surface Current ◽  
Antenna System ◽  
Antenna Element ◽  
Coupling Mechanism ◽  
Mimo Antenna ◽  
Resonant Modes ◽  
Monopole Antennas ◽  
Input Multiple Output ◽  
Ground Plate

AbstractA printed multiband Multi-Input Multiple-Output (MIMO) antenna is proposed in this paper. This MIMO antenna system comprises two symmetric printed monopole antennas. Each antenna element consists of multiple bend lines, producing four resonant modes and covering the GSM900, PCS, LTE2300, and 5G bands. Simulated and measured results prove that the proposed MIMO antenna can be applied to traditional 2G, 3G, 4G, and present 5G mobile communication. By etching four inverted L-shaped grooves on its ground plate, mutual coupling between the adjacent antenna elements has been suppressed. This makes the |S21| at all four resonant modes is lower than −40 dB. In addition, its low coupling mechanism has been analyzed by surface current distribution. The designed multiband MIMO antenna provides an idea of reference to realize low mutual coupling between antenna elements, which is also realizable in infrared or optical regimes with appropriate designs.

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