scholarly journals Design and Electromagnetic Properties of a Conformal Ultra Wideband Antenna Integrated in Three-Dimensional Woven Fabrics

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 861 ◽  
Author(s):  
Ye Kuang ◽  
Lan Yao ◽  
Sheng-Hai Yu ◽  
Shuo Tan ◽  
Xiu-Jun Fan ◽  
...  

Wearable antennas play an important role in transmitting signals wirelessly in body-worn systems, helping body-worn applications to achieve real-time monitoring and improving the working efficiency as well as the life quality of the users. Over conventional antenna types, ultra wideband (UWB) antennas have advantages of very large operating bandwidth, low power consumption, and high data transmission speed, therefore, they become of great interest for body-worn applications. One of the strategies for making the antenna comfortable to wear is replacing the conventional rigid printed circuit board with textile materials in the manufacturing process. In this study, a novel three-dimensional woven fabric integrated UWB antenna was proposed and fabricated with pure textile materials. The antenna electromagnetic properties were simulated and measured and its properties under bending were investigated. The antenna operated in a wide bandwidth from 2.7 to 13 GHz with the proper radiation pattern and gain value. At the same time, the antenna performance under bending varied in a reasonable range indicating that the antenna is prospectively applied on the curved surfaces of the human body. Additionally, the current distribution of the antenna showed that different conductive parts had different current densities indicating the uniqueness of the three-dimensional textile-based antenna.

2015 ◽  
Vol 752-753 ◽  
pp. 1406-1412
Author(s):  
Lei Zeng ◽  
Jian Chen ◽  
Han Ning Li ◽  
Bin Yan ◽  
Yi Fu Xu ◽  
...  

In modern industry, the nondestructive testing of printed circuit board (PCB) can prevent effectively the system failure and is becoming more and more important. As a vital part of the PCB, the via connects the devices, the components and the wires and plays a very important role for the connection of the circuits. With the development of testing technology, the nondestructive testing of the via extends from two dimension to three dimension in recent years. This paper proposes a three dimensional detection algorithm using morphology method to test the via. The proposed algorithm takes full advantage of the three dimensional structure and shape information of the via. We have used the proposed method to detect via from PCB images with different size and quality, and found the detection performances to be very encouraging.


2003 ◽  
Vol 11 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Y. S. Song ◽  
K. Chung ◽  
T. J. Kang ◽  
J. R. Youn

The complete prediction of the second order permeability tensor for a three dimensional multi-axial preform is critical if we are to model and design the manufacturing process for composites by considering resin flow through a multi-axial fiber structure. In this study, the in-plane and transverse permeabilities for a woven fabric were predicted numerically by the coupled flow model, which combines microscopic and macroscopic flows. The microscopic and macroscopic flows were calculated by using 3-D CVFEM(control volume finite element method) for micro and macro unit cells. To avoid a checkerboard pressure field and improve the efficiency of numerical computation, a new interpolation function for velocity is proposed on the basis of analytical solutions. The permeability of a plain woven fabric was measured by means of an unidirectional flow experiment and compared with the permeability calculated numerically. Reverse and simple stacking of plain woven fabrics were taken into account and the relationship between the permeability and the structures of the preform such as the fiber volume fraction and stacking order is identified. Unlike other studies, the current study was based on a more realistic three dimensional unit cell. It was observed that in-plane flow is more dominant than transverse flow within the woven perform, and the effect of the stacking order of a multi-layered preform was negligible.


2013 ◽  
Vol 795 ◽  
pp. 603-610 ◽  
Author(s):  
Mohamed Mazlan ◽  
A. Rahim ◽  
M.A. Iqbal ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
W. Razak ◽  
...  

Plastic Leaded Chip Carrier (PLCC) package has been emerged a promising option to tackle the thermal management issue of micro-electronic devices. In the present study, three dimensional numerical analysis of heat and fluid flow through PLCC packages oriented in-line and mounted horizontally on a printed circuit board, is carried out using a commercial CFD code, FLUENTTM. The simulation is performed for 12 PLCC under different inlet velocities and chip powers. The contours of average junction temperatures are obtained for each package under different conditions. It is observed that the junction temperature of the packages decreases with increase in inlet velocity and increases with chip power. Moreover, the increase in package density significantly contributed to rise in temperature of chips. Thus the present simulation demonstrates that the chip density (the number of packages mounted on a given area), chip power and the coolant inlet velocity are strongly interconnected; hence their appropriate choice would be crucial.


2014 ◽  
Vol 2014 (1) ◽  
pp. 000355-000360
Author(s):  
K. Macurova ◽  
R. Bermejo ◽  
M. Pletz ◽  
R. Schöngrundner ◽  
T. Antretter ◽  
...  

Important topics for electronic packages are thermally induced stresses created during package manufacturing and their role in mechanical failure. In the present paper, an analytical and a numerical analysis of the assembly process (component attached with an adhesive to a copper foil) is investigated. This process is prior to the lamination of the printed circuit board. Stresses develop due to a mismatch of coefficients of thermal expansion and particularly to shrinkage associated with adhesive polymerization. The analytical investigation is based on the classical laminate theory and an interfacial model. The three-dimensional numerical finite element model is capable to use geometric and material properties which are not possible to investigate analytically. In particular, the influence of the adhesive meniscus and plastic material models for copper and adhesive are investigated. The models are validated experimentally by an X-ray diffraction method (Rocking-Curve-Technique) showing a good agreement of the calculated and measured curvature radius values.


2015 ◽  
Vol 12 (2) ◽  
pp. 80-85 ◽  
Author(s):  
K. Macurova ◽  
R. Bermejo ◽  
M. Pletz ◽  
R. Schöngrundner ◽  
T. Antretter ◽  
...  

Important topics for electronic packages are thermally induced stresses created during package manufacturing and their role in mechanical failure. In the present paper, an analytical and a numerical analysis of the assembly process (component attached with an adhesive to a copper foil) is investigated. This process is prior to the lamination of the printed circuit board. Stresses develop due to a mismatch of coefficients of thermal expansion and particularly to shrinkage associated with adhesive polymerization. The analytical investigation is based on the classical laminate theory and an interfacial model. The three-dimensional, numerical, finite element model is capable of using geometric and material properties not possible to investigate analytically. In particular, the influence of the adhesive meniscus and plastic material models for copper and adhesive are investigated. The models are validated experimentally by an x-ray diffraction method (rocking-curve technique) showing a good agreement of the calculated and measured curvature radius values.


Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 215-219
Author(s):  
Akhendra Kumar Padavala ◽  
Narayana Kiran Akondi ◽  
Bheema Rao Nistala

Purpose This paper aims to present an efficient method to improve quality factor of printed fractal inductors based on electromagnetic band-gap (EBG) surface. Design/methodology/approach Hilbert fractal inductor is designed and simulated using high-frequency structural simulator. To improve the quality factor, an EBG surface underneath the inductor is incorporated without any degradation in inductance value. Findings The proposed inductor and Q factor are measured based on well-known three-dimensional simulator, and the results are compared experimentally. Practical implications The proposed method was able to significantly decrease the noise with increase in the speed of radio frequency and sensor-integrated circuit design. Originality/value Fractal inductor is designed and simulated with and without EBG surfaces. The measurement of printed circuit board prototypes demonstrates that the inclusion of split-ring array as EBG surface increases the quality factor by 90 per cent over standard fractal inductor of the same dimensions with a small degradation in inductance value and is capable of operating up to 2.4 GHz frequency range.


2019 ◽  
Vol 90 (11-12) ◽  
pp. 1354-1371
Author(s):  
Marzieh Javadi Toghchi ◽  
Carmen Loghin ◽  
Irina Cristian ◽  
Christine Campagne ◽  
Pascal Bruniaux ◽  
...  

The main objective of the present study was to investigate the increase in the electromagnetic shielding effectiveness (EMSE) of a set of five variants of three-dimensional (3D) warp interlock woven fabrics containing silver multifilament yarns arranged in a 3D orthogonal grid. The EMSE enlargement as a factor of increasing the quantity of the conductive material per unit area was investigated. The quantity of the conductive material per unit area in a 3D woven fabric can be enlarged by increasing either the yarn undulation or the number of conductive yarn systems, while the yarn density and yarn fineness are fixed. Thus, the binding depth of the conductive warp was gradually increased for the first four variants in order to increase the yarn undulation. Alternatively, the conductive weft system was doubled for the last variant with the aim of increasing the quantity of the conductive component. It should be noted that changing the weave structure requires less effort and energy while keeping the same threading of warps in the reed compared to altering the warp density. The EMSE was measured in an anechoic chamber and the shielding was satisfactory for all the variants in the frequency range of 1–6 GHz (19–44 dB). The results revealed that increasing only 7% of the waviness degree of the conductive warps led to 17% EMSE improvement due to increasing of the conductive yarns through the thickness of the variants. Moreover, no upward EMSE was detected for the last variant, despite the fact that the conductive weft system was doubled.


2019 ◽  
Vol 90 (11-12) ◽  
pp. 1291-1300
Author(s):  
Zhicai Yu ◽  
Yueqi Zhong ◽  
R. Hugh Gong ◽  
Haoyang Xie

To evaluate the ability of woven fabrics to drape in a more accurate way, a three-dimensional point cloud of a draped woven fabric was captured via an in-house drape-scanner. A new indicator, total drape angle (TDA), was proposed based on the three-dimensional fabric drape to characterize the ability of a woven fabric to drape. The relationship between TDA and the drape coefficient (DC) was analyzed to validate the performance of TDA. The result indicated that TDA is more stable and representative than the traditional DC in characterizing the ability of a woven fabric to drape. In addition, the drape angle distribution function (DADF) of the triangular mesh was employed to describe fabric drape, as well as to bridge the gap between drape configuration and the warp bending rigidity of woven fabric. The results showed that the correlation coefficient between the real warp bending rigidity value and what was predicted warp based on DADF and fabric weight was 0.952.


2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Sangbeom Cho ◽  
Yogendra Joshi

We develop a vapor chamber integrated with a microelectronic packaging substrate and characterize its heat transfer performance. A prototype of vapor chamber integrated printed circuit board (PCB) is fabricated through successful completion of the following tasks: patterning copper micropillar wick structures on PCB, mechanical design and fabrication of condenser, device sealing, and device vacuuming and charging with working fluid. Two prototype vapor chambers with distinct micropillar array designs are fabricated, and their thermal performance tested under various heat inputs supplied from a 2 mm × 2 mm heat source. Thermal performance of the device improves with heat inputs, with the maximum performance of ∼20% over copper plated PCB with the same thickness. A three-dimensional computational fluid dynamics/heat transfer (CFD/HT) numerical model of the vapor chamber, coupled with the conduction model of the packaging substrate is developed, and the results are compared with test data.


2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Jorge Mireles ◽  
Ho-Chan Kim ◽  
In Hwan Lee ◽  
David Espalin ◽  
Francisco Medina ◽  
...  

This research focused on extending the applications of fused deposition modeling (FDM) by extrusion and deposition of low melting temperature metal alloys to create three-dimensional metal structures and single-layer contacts which may prove useful for electronic interconnects. Six commercially available low melting temperature solder alloys (Bi36Pb32Sn31Ag1, Bi58Sn42, Sn63Pb37, Sn50Pb50, Sn60Bi40, Sn96.5Ag3.5) were tested for the creation of a fused deposition modeling for metals (FDMm) system with special attention given to Sn–Bi solders. An existing FDM 3000 was used and two alloys were successfully extruded through the system's extrusion head. Deposition was achieved through specific modifications to system toolpath commands and a comparison of solders with eutectic and non-eutectic compositions is discussed. The modifications demonstrate the ability to extrude simple single-layer solder lines with varying thicknesses, including sharp 90 deg angles and smooth curved lines and showing the possibility of using this system for printed circuit board applications in which various connections need to be processed. Deposition parameters altered for extrusion and the deposition results of low melting temperature metal alloys are introduced.


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