scholarly journals Miniaturized Coupling Structures for Decoupling PIFAs on Handheld Devices

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Qian Li ◽  
Yaxin Yu
Keyword(s):  
Electromagnetic Field ◽  
Correlation Coefficient ◽  
Dielectric Layer ◽  
Mutual Coupling ◽  
Ground Plane ◽  
Measured Data ◽  
Handheld Devices ◽  
Handheld Device ◽  
Small Spacing ◽  
Thin Dielectric Layer

One efficient approach is introduced in this paper to reduce mutual coupling and correlation coefficient for two closely placed PIFAs in a handheld device. The approach is based on one miniaturized structure which consists of two metallic layers, printed on either side of one thin dielectric layer. Due to the small spacing between two conducting patches, high electromagnetic field is induced within the dielectric layer. The geometry and position of this structure have been modified to decouple the PIFA array at 1.9 GHz and produce maximum miniaturization thereby occupying less space on a handheld device ground plane. By employing the proposed structures, a 20 dB reduction in mutual coupling is achieved. The correlation coefficient also reduces to 0.007278. The performance of the structure is validated by both simulated results and measured data obtained from several fabricated prototypes.

scholarly journals A Compact Dual-Band Printed Antenna Design for LTE Operation in Handheld Device Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ding-Bing Lin ◽  
Jui-Hung Chou ◽  
Son-On Fu ◽  
Hsueh-Jyh Li
Keyword(s):  
Reflection Coefficient ◽  
Frequency Band ◽  
Ground Plane ◽  
Low Frequency ◽  
Dual Band ◽  
Handheld Devices ◽  
Printed Antenna ◽  
Handheld Device ◽  
Path Lengths ◽  
Definition Of

A novel internal printed antenna suitable for triple long-term evolution (LTE) bands for handheld devices is presented. The operating bandwidths of the design are LTE700 (698~800 MHz), LTE2300 (2300~2400 MHz), and LTE2500 (2500~2690 MHz). Through the use of a C-shape broadside coupled feed structure, full operation in the lower band is achieved. The antenna itself uses two unequal path lengths to produce a low frequency band with two resonant modes. The required bandwidth is then adjusted using a couple feed, and finally placed over a ground plane via another C-type coupling element in order to enhance the two low-frequency matches. In the definition of the −6 dB reflection coefficient, the bandwidth of two basic modes in the low frequency band is 0.689~0.8 GHz. We adopt the definition of the −10 dB reflection coefficient for the high frequency mode, and its working frequency bands are shown to be 2.3~2.72 GHz. The antenna size is only 40 × 12 × 0.8 mm3with a ground plane of 98 × 40 mm2.

scholarly journals Real-Time Single Image Depth Perception in the Wild with Handheld Devices

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 15
Author(s):  
Filippo Aleotti ◽  
Giulio Zaccaroni ◽  
Luca Bartolomei ◽  
Matteo Poggi ◽  
Fabio Tosi ◽  
...  
Keyword(s):  
Real Time ◽  
Depth Perception ◽  
Depth Estimation ◽  
Autonomous Driving ◽  
Estimation Methods ◽  
Handheld Devices ◽  
Single Image ◽  
Handheld Device ◽  
Time Performance ◽  
In The Wild

Depth perception is paramount for tackling real-world problems, ranging from autonomous driving to consumer applications. For the latter, depth estimation from a single image would represent the most versatile solution since a standard camera is available on almost any handheld device. Nonetheless, two main issues limit the practical deployment of monocular depth estimation methods on such devices: (i) the low reliability when deployed in the wild and (ii) the resources needed to achieve real-time performance, often not compatible with low-power embedded systems. Therefore, in this paper, we deeply investigate all these issues, showing how they are both addressable by adopting appropriate network design and training strategies. Moreover, we also outline how to map the resulting networks on handheld devices to achieve real-time performance. Our thorough evaluation highlights the ability of such fast networks to generalize well to new environments, a crucial feature required to tackle the extremely varied contexts faced in real applications. Indeed, to further support this evidence, we report experimental results concerning real-time, depth-aware augmented reality and image blurring with smartphones in the wild.

scholarly journals Thermos Array: Two-Dimensional Sparse Array with Reduced Mutual Coupling

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Sun ◽  
Minglei Yang ◽  
Baixiao Chen
Keyword(s):  
Closed Form ◽  
Degrees Of Freedom ◽  
Mutual Coupling ◽  
Doa Estimation ◽  
Two Dimensional ◽  
Spatial Smoothing ◽  
Planar Arrays ◽  
Half Wavelength ◽  
Planar Array ◽  
Small Spacing

Sparse planar arrays, such as the billboard array, the open box array, and the two-dimensional nested array, have drawn lots of interest owing to their ability of two-dimensional angle estimation. Unfortunately, these arrays often suffer from mutual-coupling problems due to the large number of sensor pairs with small spacing d (usually equal to a half wavelength), which will degrade the performance of direction of arrival (DOA) estimation. Recently, the two-dimensional half-open box array and the hourglass array are proposed to reduce the mutual coupling. But both of them still have many sensor pairs with small spacing d, which implies that the reduction of mutual coupling is still limited. In this paper, we propose a new sparse planar array which has fewer number of sensor pairs with small spacing d. It is named as the thermos array because its shape seems like a thermos. Although the resulting difference coarray (DCA) of the thermos array is not hole-free, a large filled rectangular part in the DCA can be facilitated to perform spatial-smoothing-based DOA estimation. Moreover, it enjoys closed-form expressions for the sensor locations and the number of available degrees of freedom. Simulations show that the thermos array can achieve better DOA estimation performance than the hourglass array in the presence of mutual coupling, which indicates that our thermos array is more robust to the mutual-coupling array.

scholarly journals Omnidirectional antenna with modified ground plane for wideband DVB in handheld devices

2021 ◽  
Vol 13 ◽  
pp. e00872
Author(s):  
Joseph Owusu ◽  
Mohamad Rijal Bin Hamid ◽  
Samuel Tweneboah-Koduah ◽  
Samuel Afoakwa
Keyword(s):  
Ground Plane ◽  
Handheld Devices ◽  
Omnidirectional Antenna

scholarly journals Dual Feed, Single Element Antenna for WiMAX MIMO Application

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Frank M. Caimi ◽  
Mark Mongomery
Keyword(s):  
Correlation Coefficient ◽  
Performance Metrics ◽  
Measured Data ◽  
Antenna Pattern ◽  
Relative Performance ◽  
Equal Length ◽  
Impedance Match ◽  
Single Element ◽  
Pattern Correlation ◽  
Operating Bandwidth

A novel u-shaped single element antenna having two feed ports is compared with two equal length monopoles separated by a distance equivalent to the width. A discussion of relative performance metrics is provided for MIMO applications, and measured data is given for comparison. Good impedance match and isolation of greater than  dB are observed over the operating bandwidth from 2.3 to 2.39 GHz. The antenna patterns are highly uncorrelated, as illustrated by computation of the antenna pattern correlation coefficient for the two comparison monopoles.

Mutual coupling reduction of low-profile monopole antennas on high-impedance ground plane

2002 ◽  
Vol 38 (16) ◽  
pp. 849 ◽  
Author(s):  
H. Xin ◽  
K. Matsugatani ◽  
M. Kim ◽  
J. Hacker ◽  
J.A. Higgins ◽  
...  
Keyword(s):  
Mutual Coupling ◽  
Ground Plane ◽  
High Impedance ◽  
Low Profile ◽  
Monopole Antennas ◽  
Mutual Coupling Reduction

Bio-inspired Passive Skin Cooling for Handheld Microelectronics Devices

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Zhi Huang ◽  
Xinsheng Zhang ◽  
Ming Zhou ◽  
Xiaoding Xu ◽  
Xianzheng Zhang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Handheld Devices ◽  
Solution Temperature ◽  
Passive Cooling ◽  
Temperature Sensitive ◽  
Operation System ◽  
Critical Solution Temperature ◽  
Handheld Device ◽  
Skin Cooling ◽  
Cooling Technology

Increasing functionality demands more heat dissipation from the skin of handheld devices. The maximum amount of heat that can be dissipated passively, prescribed by the natural convection and blackbody radiation theories, is becoming the bottleneck. In this letter, we propose a novel bio-inspirited technique that may overcome this passive cooling limit. It is made possible by using a biomimetic skin capable of perspiration on demand. The key component of the biomimetic skin is a thin layer of temperature sensitive hydro gel (TSHG). The TSHG layer can sweat the skin with moisture when the skin temperature is higher than the TSHG’s lower critical solution temperature (LCST), and thus boost the heat dissipation rate through evaporation. The TSHG layer can absorb moisture at low temperature to replenish. With this novel passive cooling technology, a handheld device can have nearly four times more power beyond the traditional passive cooling limit, and may be powerful enough to run a desktop operation system like a full functional personal computer.

Three Dimensional Bacteria Concentration by Negative Dielectrophoresis

2013 ◽  
Vol 699 ◽  
pp. 251-256
Author(s):  
T. Hisajima ◽  
L. Mao ◽  
K. Shinzato ◽  
M. Nakano ◽  
J. Suehiro
Keyword(s):  
Escherichia Coli ◽  
Numerical Simulation ◽  
Dielectric Layer ◽  
Parallel Plate ◽  
Three Dimensional ◽  
Three Dimension ◽  
Escherichia Coli Cells ◽  
Opposite Electrode ◽  
Novel Method ◽  
Thin Dielectric Layer

Thispaper reports a novel method to concentrate bacteria in three-dimension by negative dielectrophoretic (n-DEP) force in a microchannel. This was achieved by placing a thin dielectric layer on one of a pair of parallel plate electrodes. The dielectric layer having a home-plate like pentagonal shape, forms a gradient of electric field causing n-DEP. A three-dimensional numerical simulation of bacteria trajectory predicts that bacteria flowing a microchannel were three-dimensionally concentrated beneath the tip of the pentagonal dielectric thin layer. The trajectory and concentration of bacteria under n-DEP force were also experimentally confirmed using Escherichia coli cells. Bacteria moved along edges of the dielectric layer and were pushed to the opposite electrode, resulting in their concentration in three-dimension. The proposed device might be applicable to selective concentration of bacteria depending on their dielectric properties.

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