scholarly journals Performance Enhancement of mm-Wave Phased Arrays for Mobile Terminals Through Grounded Coplanar Waveguide Feeding Networks With via Fences

2021 ◽  
Vol 2 ◽  
Author(s):  
Jae-Yeong Lee ◽  
Jaehyun Choi ◽  
Bumhyun Kim ◽  
Yerim Oh ◽  
Wonbin Hong
Keyword(s):  
Phased Arrays ◽  
Performance Enhancement ◽  
Coplanar Waveguide ◽  
Experimental Studies ◽  
Single Layer ◽  
Power Divider ◽  
Electromagnetic Bandgap ◽  
Mobile Terminals ◽  
One Dimensional ◽  
High Impedance

This paper presents a design methodology focused on feeding networks that can improve the insertion loss and coverage efficiencies of millimeter-wave (mm-Wave) phased arrays in mobile terminals. This enhancement is accomplished by using a grounded coplanar waveguide (GCPW) transmission line (TL) with via fences fabricated on single-layer FR-4 PCB. The exemplified 8-element phased arrays incorporating a compact one-dimensional electromagnetic bandgap (1-D EBG) antenna are fed through a 1 × 8 T-junction power divider, which includes the predetermined phased delay lines. To achieve high radiation performance with minimum leakage power or spurious waves in the T-junction power divider, an island-shape GCPW TL topology with via fences featuring high-impedance surfaces (HIS) is devised and fabricated. For further investigation on the radiation performance and spherical coverage of the mm-Wave mobile antenna, a mobile device prototype equipped with two sets of the 8-element phased arrays is prepared and studied. Through extensive simulation and experimental studies, it can be ascertained that the proposed GCPW TL topology with via fences can improve the realized gain at a coverage efficiency of 50% by more than 3 dB, between 26 and 36 GHz.

Stub-Loaded Wilkinson Power Divider with Performance Enhancement

2015 ◽  
Vol 24 (08) ◽  
pp. 1550127
Author(s):  
Huan-Zhu Wang ◽  
Jia-Lin Li ◽  
Jian-Peng Wang ◽  
Wei Shao ◽  
Xue-Song Yang
Keyword(s):  
Transmission Lines ◽  
Performance Enhancement ◽  
Size Reduction ◽  
Power Divider ◽  
Harmonic Suppression ◽  
Power Dividers ◽  
High Impedance ◽  
Wilkinson Power Divider ◽  
Harmonic Components ◽  
Wilkinson Power Dividers

Microstrip Wilkinson power dividers with harmonic suppression and size reduction are investigated. It is found that by loading reactive components at the middle of high impedance transmission lines (TLs), both size reduction and harmonic suppression can be achieved. Analyses and designs of such a kind of power divider are formulated in this paper. To demonstrate the design methodology, two power dividers centered at 1.8 GHz are optimally designed and confirmed by experiments. As compared with conventional Wilkinson power divider, the proposed power divider exhibits 55.6% size reduction, and high suppressions are achieved for 2nd and 3rd harmonic components. Both simulations and measurements are presented with good agreement.

One-Dimensional Contact Pressure Distribution of Radial Tires in Motion

1995 ◽  
Vol 23 (2) ◽  
pp. 116-135 ◽  
Author(s):  
H. Shiobara ◽  
T. Akasaka ◽  
S. Kagami ◽  
S. Tsutsumi
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Experimental Studies ◽  
Rolling Resistance ◽  
Leading Edge ◽  
Forward Direction ◽  
Contact Pressure Distribution ◽  
Support Ring ◽  
One Dimensional ◽  
Lowered Pressure

Abstract The contact pressure distribution and the rolling resistance of a running radial tire under load are fundamental properties of the tire construction, important to the steering performance of automobiles, as is well known. Many theoretical and experimental studies have been previously published on these tire properties. However, the relationships between tire performances in service and tire structural properties have not been clarified sufficiently due to analytical and experimental difficulties. In this paper, establishing a spring support ring model made of a composite belt ring and a Voigt type viscoelastic spring system of the sidewall and the tread rubber, we analyze the one-dimensional contact pressure distribution of a running tire at speeds of up to 60 km/h. The predicted distribution of the contact pressure under appropriate values of damping coefficients of rubber is shown to be in good agreement with experimental results. It is confirmed by this study that increasing velocity causes the pressure to rise at the leading edge of the contact patch, accompanied by the lowered pressure at the trailing edge, and further a slight movement of the contact area in the forward direction.

Analysis of doubly periodic electromagnetic bandgap filters in coplanar waveguide technology

2004 ◽  
Author(s):  
Francisco Falcone ◽  
Ferran Martin ◽  
J. Bonache ◽  
Txema Lopetegi ◽  
Miguel A. Laso ◽  
...  
Keyword(s):  
Coplanar Waveguide ◽  
Electromagnetic Bandgap

scholarly journals Finite Element Prediction for the Internal Stresses of (Ti,Al)N Coatings

2016 ◽  
Vol 61 (1) ◽  
pp. 149-152 ◽  
Author(s):  
L.W. Żukowska ◽  
A. Śliwa ◽  
J. Mikuła ◽  
M. Bonek ◽  
W. Kwaśny ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Computer Simulation ◽  
Finite Element ◽  
Experimental Studies ◽  
Single Layer ◽  
Internal Stresses ◽  
Pvd Coatings ◽  
Properties Of Coatings ◽  
Gradient Coatings ◽  
Element Method

The general topic of this paper is the computer simulation with use of finite element method (FEM) for determining the internal stresses of selected gradient and single-layer PVD coatings deposited on the sintered tool materials, including cemented carbides, cermets and Al2O3+TiC type oxide tool ceramics by cathodic arc evaporation CAE-PVD method. Developing an appropriate model allows the prediction of properties of PVD coatings, which are also the criterion of their selection for specific items, based on the parameters of technological processes. In addition, developed model can to a large extent eliminate the need for expensive and time-consuming experimental studies for the computer simulation. Developed models of internal stresses were performed with use of finite element method in ANSYS environment. The experimental values of stresses were calculated using the X-ray sin2ψ technique. The computer simulation results were compared with the experimental results. Microhardness and adhesion as well as wear range were measured to investigate the influence of stress distribution on the mechanical and functional properties of coatings. It was stated that occurrence of compressive stresses on the surface of gradient coating has advantageous influence on their mechanical properties, especially on microhardness. Absolute value reduction of internal stresses in the connection zone in case of the gradient coatings takes profitably effects on improvement the adhesion of coatings. It can be one of the most important reasons of increase the wear resistance of gradient coatings in comparison to single-layer coatings.

scholarly journals Comparison of FASST and SNTHERM in Three Snow Accumulation Regimes

2008 ◽  
Vol 9 (6) ◽  
pp. 1443-1463 ◽  
Author(s):  
Susan Frankenstein ◽  
Anne Sawyer ◽  
Julie Koeberle
Keyword(s):  
Surface Energy ◽  
Single Layer ◽  
Soil Strength ◽  
Snow Accumulation ◽  
Dynamic State ◽  
Energy Fluxes ◽  
One Dimensional ◽  
Surface Energy Fluxes ◽  
Snow Model ◽  
Surface Ice

Abstract Numerical experiments of snow accumulation and depletion were carried out as well as surface energy fluxes over four Cold Land Processes Experiment (CLPX) sites in Colorado using the Snow Thermal model (SNTHERM) and the Fast All-Season Soil Strength model (FASST). SNTHERM is a multilayer snow model developed to describe changes in snow properties as a function of depth and time, using a one-dimensional mass and energy balance. The model is intended for seasonal snow covers and addresses conditions found throughout the winter, from initial ground freezing in the fall to snow ablation in the spring. It has been used by many researchers over a variety of terrains. FASST is a newly developed one-dimensional dynamic state-of-the-ground model. It calculates the ground’s moisture content, ice content, temperature, and freeze–thaw profiles as well as soil strength and surface ice and snow accumulation/depletion. Because FASST is newer and not as well known, the authors wanted to determine its use as a snow model by comparing it with SNTHERM, one of the most established snow models available. It is demonstrated that even though FASST is only a single-layer snow model, the RMSE snow depth compared very favorably against SNTHERM, often performing better during the accumulation phase. The surface energy fluxes calculated by the two models were also compared and were found to be similar.

New periodic-loaded electromagnetic bandgap coplanar waveguide with complete spurious passband suppression

2002 ◽  
Vol 12 (11) ◽  
pp. 435-437 ◽  
Author(s):  
F. Martin ◽  
F. Falcone ◽  
J. Bonache ◽  
T. Lopetegi ◽  
M.A.G. Laso ◽  
...  
Keyword(s):  
Coplanar Waveguide ◽  
Electromagnetic Bandgap
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