scholarly journals Enhanced Loop Structure of NFC Antenna for Mobile Handset Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Byungje Lee ◽  
Byeongkwan Kim ◽  
Sunghyun Yang
Keyword(s):  
Polymer Composite ◽  
Relative Permeability ◽  
Eddy Current ◽  
Loop Antenna ◽  
Battery Pack ◽  
Loop Structure ◽  
Embedded Capacitor ◽  
Performance Deterioration ◽  
Mobile Handset

A new structure of an NFC loop antenna for mobile handset applications is proposed. The proposed antenna consists of conventional loop elements and a parasitic loop embedded capacitor to enhance its performance. Although the sintered ferrite sheets with higher relative permeability(μr≈200)have been used to reduce the performance deterioration due to the eddy current on the battery pack of a mobile handset, their costs are high, and they are considerably breakable. In this paper, with the proposed structure, we effectively enhance the performance of an NFC loop antenna by employing the ferrite-polymer composite with lower relative permeability(μr≈55).

scholarly journals Miniaturized Wideband Loop Antenna Using a Multiple Half-Circular-Ring-Based Loop Structure and Horizontal Slits for Terrestrial DTV and UHD TV Applications

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2916
Author(s):  
Junho Yeo ◽  
Jong-Ig Lee
Keyword(s):  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Circular Ring ◽  
Loop Antenna ◽  
Digital Television ◽  
Loop Structure ◽  
High Definition ◽  
Circular Sector ◽  
Feed Line ◽  
Length Reduction

A miniaturized wideband loop antenna for terrestrial digital television (DTV) and ultra-high definition (UHD) TV applications is proposed. The original wideband loop antenna consists of a square loop, two circular sectors to connect the loop with central feed points, and a 75 ohm coplanar waveguide (CPW) feed line inserted in the lower circular sector. The straight side of the square loop is replaced with a multiple half-circular-ring-based loop structure. Horizontal slits are appended to the two circular sectors in order to further reduce the antenna size. A tapered CPW feed line is also employed in order to improve impedance matching. The experiment results show that the proposed miniaturized loop antenna operates in the 460.7–806.2 MHz frequency band for a voltage standing wave ratio less than two, which fully covers the DTV and UHD TV bands (470–771 MHz). The proposed miniaturized wideband loop antenna has a length reduction of 21.43%, compared to the original loop antenna.

Folded Dual-Loop Antenna for GSM/DCS/PCS/UMTS Mobile Handset Applications

2010 ◽  
Vol 9 ◽  
pp. 998-1001 ◽  
Author(s):  
Chia-Hao Ku ◽  
Hsien-Wen Liu ◽  
Sheng-Yu Lin
Keyword(s):  
Loop Antenna ◽  
Mobile Handset

Internal folded loop antenna with tuning notches for GSM/GPS/DCS/PCS mobile handset applications

2006 ◽  
Vol 48 (8) ◽  
pp. 1501-1504 ◽  
Author(s):  
Byungwoon Jung ◽  
Hanphil Rhyu ◽  
Young-Joong Lee ◽  
Frances J. Harackiewicz ◽  
Myun-Joo Park ◽  
...  
Keyword(s):  
Loop Antenna ◽  
Mobile Handset

Study on extraction of electrical runout in eddy current measurement using finite element method

2013 ◽  
Vol 228 (6) ◽  
pp. 1077-1086 ◽  
Author(s):  
Xiaolong Chen ◽  
Yanlong Cao ◽  
Zaiyu Lin ◽  
Jiangxin Yang ◽  
Xiaoqi Hu
Keyword(s):  
Finite Element ◽  
Relative Permeability ◽  
Imaginary Part ◽  
Eddy Current ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Current Sensor ◽  
The Real ◽  
Eddy Current Sensor ◽  
Lift Off

Electrical runout is a bottleneck problem of eddy current sensor, which is caused by the maldistribution/variation of material electromagnetic properties of measurement target. However, extraction methods of electrical runout in eddy current displacement measurement remain ambiguous. Here, a 2D finite element model for the influence analysis of conductivity and permeability of ferromagnetic material on coil impedance of eddy current sensor is reported, which will be beneficial for detecting material properties and guiding manufacturing process. The relationships between the real and imaginary part of coil impedance with the varied material conductivity, relative permeability and the lift-off, which indicates the detecting distance, are investigated. When the conductivity, relative permeability of ferromagnetic material and the lift-off vary within a certain range, the relationships between the real and imaginary part of coil impedance are all nearly linear. This paper further shows that the character of distribution of resistance and reactance in diagram under different material properties and same measuring distance is linear. Furthermore, these lines under different measuring distances are parallel. Also the character under different measuring distances and same material property is linear, but these lines under different material properties are diffuse with same intercept. Altogether, the study shows that this method based on redesign of signal processing and its circuit is feasible and instructive in separating electrical runout from the output of eddy current sensor.

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