Development of Ultra-Thin Thermal Ground Plane with High Performance Electroplated Wick

2020 ◽  
Author(s):  
Ian Hu ◽  
Hung-Hsien Huang ◽  
Po-Cheng Huang ◽  
Jui-Cheng Yu ◽  
Chien-Neng Liao ◽  
...  
Keyword(s):  
High Performance ◽  
Ground Plane ◽  
Thermal Ground Plane

Burst Oscillations in the Accelerating Bicycle

2010 ◽  
Vol 77 (6) ◽  
Author(s):  
David J. N. Limebeer ◽  
Amrit Sharma
Keyword(s):  
High Performance ◽  
Dynamic Models ◽  
Ground Plane ◽  
Logarithmic Spiral ◽  
Arbitrary Point ◽  
Time Scale Separation ◽  
Bicycle Model ◽  
Control Scheme ◽  
Road Surfaces ◽  
Time Invariant

The purpose of this paper is to study the dynamics of the accelerating bicycle. It is shown that time-scale separation can be used to study the oscillatory characteristics of the accelerating machine using time-invariant models. These models are used to explain practically observed wobble-mode bursting oscillations that are associated most frequently with down-hill riding. If the vehicle is cornering under constant acceleration, at a fixed roll angle, it is shown that for low values of acceleration (and braking), it follows closely a logarithmic spiral shaped trajectory. The studies presented are facilitated by a novel adaptive control scheme that centers the machine’s trajectory on any arbitrary point in the ground plane. The influences of cambered road surfaces are also investigated. The bicycle model employed is an extension of that originally developed by Whipple, and comprises two road wheels and two laterally-symmetric frame assemblies that are free to rotate relative to each other along an inclined steering axis. For the most part, the front frame is treated as being flexible and the bicycle is fitted with force generating road tires, rather than classical nonholonomic rolling constraints. This research provides the ground work required for generating more complex dynamic models for high-performance motorcycle studies.

A large scale Titanium Thermal Ground Plane

2013 ◽  
Vol 62 ◽  
pp. 178-183 ◽  
Author(s):  
Marin Sigurdson ◽  
YuWei Liu ◽  
Payam Bozorgi ◽  
David Bothman ◽  
Noel MacDonald ◽  
...  
Keyword(s):  
Large Scale ◽  
Ground Plane ◽  
Thermal Ground Plane

Broadband MIMO antenna for HiperLAN/2, WLAN, and WiMAX applications with high isolation

2015 ◽  
Vol 8 (2) ◽  
pp. 309-317 ◽  
Author(s):  
Raefat Jalila El Bakouchi ◽  
Marc Brunet ◽  
Tchanguiz Razban ◽  
Abdelilah Ghammaz
Keyword(s):  
High Performance ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Ground Plane ◽  
Local Area ◽  
Area Network ◽  
Mimo Antenna ◽  
High Isolation ◽  
Large Bandwidth ◽  
S Parameters

This paper presents a multiple-input and multiple-output dual-element planar inverted-F antenna (PIFA) array for broadband operation covering the HIgh PERformance radio Local Area Network/2 (5.2 GHz/5.6 GHz), Wireless Local Area Network (5.2 GHz/5.8 GHz), and the Worldwide Interoperability for Microwave Access (5.5 GHz) bands for the compact wireless communication devices. The antenna dimension is reduced substantially with a miniature ground plane. The PIFA array provides a large bandwidth (670 MHz) and a high isolation between its ports less than −26 dB. The proposed antenna has been analyzed and designed with Ansoft HFSS v.11. Then a prototype was fabricated and tested for its performance in terms of bandwidth, S-parameters, and radiation pattern. A parametric study is made to analyze the effect of different PIFA parameters on the operating frequency and the S-parameters. The diversity performances are evaluated using computer simulation technology microwave studio (CSTMWS). The broadband performance and the high isolation are achieved in both simulation and measurement.

scholarly journals Design, Construction and Validation of a High-Performance OATS

2021 ◽  
Author(s):  
Donglin Meng
Keyword(s):  
High Performance ◽  
Ground Plane ◽  
Test Site ◽  
The World ◽  
And Performance ◽  
Antenna Factor ◽  
First Time ◽  
Biconical Antennas ◽  
Calibration Laboratories

The state of the art on the open-area test site (OATS) has been introduced. Key technologies on the design and validation of a high-performance OATS have been provided. Some famous OATS in the world regarding their structure, the dimensions of the ground plane (GP), the location of the control room, and performance are listed in a table. A case study is provided on NIM’s high-performance OATS. Many details are open for the first time, which show the fine design. A measurement uncertainty example has been provided in measuring the free-space antenna factor of biconical antennas. These results are based on the author’s many years of experience, with lots of valuable data and photos. It is intended for calibration laboratories, for EMC antenna users, for writing EMC standards, as well as for the assessors in EMC.

Charging Station of a Planar Miniature Heat Pipe Thermal Ground Plane

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Mohammed T. Ababneh ◽  
Shakti Chauhan ◽  
Frank M. Gerner ◽  
Doug Hurd ◽  
Peter de Bock ◽  
...  
Keyword(s):  
High Performance ◽  
Ground Plane ◽  
Heat Pipes ◽  
Working Fluid ◽  
Liquid Volume ◽  
Two Phase ◽  
Gravitational Fields ◽  
Charging Station ◽  
Error Characterization ◽  
Key Factor

Thermal ground planes (TGPs) are planar, thin (thickness of 3 mm or less) heat pipes which use two-phase heat transfer. The objective is to utilize TGPs as thermal spreaders in several microelectronic cooling applications. TGPs are innovative high-performance, integrated systems able to operate at a high power density with a reduced weight and temperature gradient. Moreover, being able to dissipate large amounts of heat, they have very high effective axial thermal conductivities and can operate in high adverse gravitational fields due to nanoporous wicks. A key factor in the design of the TGP is evacuation prior to filling and introduction of the proper amount of working fluid (water) into the device. The major challenge of this work is to fill heat pipes with a total liquid volume of less than 1 ml, without being able to see into the device. The current filling station is an improvement over the current state of the art as it allows for accurate filling of microliter sized volumes. Tests were performed to validate performance of the system and to verify that little to no noncondensable gasses were introduced to the system. Careful calibration of the amount of liquid introduced is important. Therefore, calibration of the burettes utilized for a liquid fill range of 0.01 ml to 100 ml was important. The magnitude of the pressure inside the TGP device is also an important factor. Charging station validation demonstrated the capability of charging TGPs with accuracy of ±1.64 μl. Calibration curves for the burettes and error characterization curves for a range of liquid charging volumes will be presented and discussed in this paper.

Development and Experimental Validation of a Micro/Nano Thermal Ground Plane

2011 ◽  
Author(s):  
H. Peter J. de Bock ◽  
Shakti Chauhan ◽  
Pramod Chamarthy ◽  
Chris Eastman ◽  
Stanton Weaver ◽  
...  
Keyword(s):  
Experimental Validation ◽  
Ground Plane ◽  
Electronics Cooling ◽  
Heat Pipes ◽  
Working Fluid ◽  
Heat Sources ◽  
Two Phase ◽  
Evaporation And Condensation ◽  
Two Phase Heat Transfer ◽  
Thermal Ground Plane

Heat pipes are commonly used in electronics cooling applications to spread heat from a concentrated heat source to a larger heat sink. Heat pipes work on the principles of two-phase heat transfer by evaporation and condensation of a working fluid. The amount of heat that can be transported is limited by the capillary and hydrostatic forces in the wicking structure of the device. Thermal ground planes are two-dimensional high conductivity heat pipes that can serve as thermal ground to which heat can be rejected by a multitude of heat sources. As hydrostatic forces are dependent on gravity, it is commonly known that heat pipe and thermal ground plane performance is orientation dependent. The effect of variation of gravity force on performance is discussed and the development of a miniaturized thermal ground plane for high g operation is described. In addition, experimental results are presented from zero to −10g acceleration. The study shows and discusses that minimal orientation or g-force dependence can be achieved if pore dimensions in the wicking structure can be designed at micro/nano-scale dimensions.

scholarly journals DESIGN OF COMPACT PRINTED RECTANGULAR MONOPOLE ANTENNA AND U- SHAPED MONOPOLE ANTENNA FOR L-BAND AND S-BAND APPLICATIONS

2012 ◽  
pp. 106-110
Author(s):  
N.SURESH BABU
Keyword(s):  
High Performance ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Consumer Electronics ◽  
Planar Surfaces ◽  
Low Profile ◽  
Monopole Antennas ◽  
Printed Monopole ◽  
L Band ◽  
Commercial Applications

In this paper we have investigated printed monopole antennas, which is basically a printed micro strip antenna with etched ground plane for multi-band applications. In particular we have fabricated and tested printed monopole antennas for L-band and S-band applications. Printed rectangular monopole antennas are studied first for L-band applications. In high performance aircraft, spacecraft, satellite, missile and consumer electronics applications, where weight, cost, performance, ease of installation, and aerodynamic profile are constraints, low profile antennas may be required. Presently there are many other government and commercial applications, such as mobile radio and wireless communications that have similar specification. To meet these requirements, micro strip patch antennas can be used. These antennas are low profile, conformable to planar and non planar surfaces, simple and inexpensive to manufacture. In this thesis mainly we have designed Rectangular printed monopole antenna and U-shape Printed monopole antennas for L-band and S-bands applications. The final structures are presented in this report after doing an extensive simulation study and analysis and presented relevant results.

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