scholarly journals Novel Multiband Metal-Rimmed Antenna for Wearable Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Liu ◽  
Jianghong Han ◽  
Songhua Hu ◽  
Li Zhang
Keyword(s):  
Numerical Simulations ◽  
Human Body ◽  
Free Space ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Ground Plane ◽  
Large Area ◽  
Specific Absorption ◽  
Additional Resonance ◽  
Feeding Structure

A novel multiband antenna with an unbroken metal rim for wearable applications is presented. In order to achieve a wideband behavior, minimizing at the same time the size of the clearance area on the antenna ground plane, a novel feeding structure is proposed. This is achieved by connecting the metal rim to the ground plane thus allowing generating one lower-frequency resonance without occupying a large area. An additional resonance is then obtained using a suitable shorting patch. In this way, the proposed antenna presents a broadband behavior, while the width of the clearance area on the ground plane is of only 2 mm. The antenna performances in free-space and on a human phantom simulating a human body are analyzed by means of numerical simulations. Finally, the specific absorption rate (SAR) is analyzed to establish the antenna reliability in wearable applications. The experimental results demonstrate superior and stable performances of the metal-rimmed antenna when it is employed in wearable applications.

Variability of Specific Absorption Rate of Human Body for Various Configurations of Tablet Computer in Vicinity of Abdomen

2015 ◽  
Vol E98.B (7) ◽  
pp. 1173-1181 ◽  
Author(s):  
Akihiro TATENO ◽  
Tomoaki NAGAOKA ◽  
Kazuyuki SAITO ◽  
Soichi WATANABE ◽  
Masaharu TAKAHASHI ◽  
...  
Keyword(s):  
Human Body ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Tablet Computer ◽  
Specific Absorption

scholarly journals Improved Handset Antenna Performance via an Electrically Extended Ground Plane

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shirook M. Ali ◽  
Huanhuan Gu ◽  
Kelce Wilson ◽  
James Warden
Keyword(s):  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Near Field ◽  
Ground Plane ◽  
Practical Approach ◽  
Far Field ◽  
Specific Absorption ◽  
Antenna Performance ◽  
Field Patterns ◽  
Surface Metal

A novel and practical approach is presented providing improved antenna performance without enlarging the antenna or the ground plane. The approach electrically extends the ground plane using wire(s) that behave as surface metal extensions of the ground plane. The wire extensions can be accommodated within typical handset housing or as part of the stylish metal used on the handset’s exterior perimeter; hence don’t require enlargement of the device. Consequently, this approach avoids the costs and limitations traditionally associated with physically lengthening of a ground plane. Eight variations are presented and compared with baseline antenna performance. Both far-field patterns and near-field electromagnetic scans demonstrate that the proposed approach controls the electrical length of the ground plane and hence its chassis wavemodes, without negatively impacting the characteristics of the antenna. Improvements in performance of up to 56% in bandwidth at 900 MHz and up to 12% in efficiency with a reduction of up to 12% in the specific absorption rate (SAR) are achieved. An 8% increase in efficiency with a 1.3% improvement in bandwidth and a 20% reduction in SAR is achieved at 1880 MHz. Thus, improvements in bandwidth are achieved without compromising efficiency. Further, improvements at lower frequencies do not compromise performance at higher frequencies.

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