scholarly journals Wideband and High-Gain Wearable Antenna Array with Specific Absorption Rate Suppression

Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2056
Author(s):  
Haoran Zu ◽  
Bian Wu ◽  
Peibin Yang ◽  
Wenhua Li ◽  
Jinjin Liu
Keyword(s):  
Antenna Array ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
High Gain ◽  
Specific Absorption ◽  
Wearable Antenna ◽  
Measurement Results ◽  
Rate Suppression ◽  
Radiation Direction ◽  
Good Agreement

In this paper, a wideband and high-gain antenna array with specific absorption rate suppression is presented. By adopting the wideband monopole antenna array and the uniplanar compact electromagnetic band gap (UC-EBG) structure, the proposed wearable antenna array can realize a high gain of 11.8–13.6 dBi within the operating band of 4.5–6.5 GHz. The sidelobe level of the proposed wearable antenna array is less than −12 dB, and the cross polarization in the main radiation direction is less than −35 dB. Benefiting from the UC-EBG design, the specific absorption rate is suppressed effectively, guaranteeing the safety of the proposed antenna array to the human body. The proposed antenna array is processed and tested, and the measurement results show good agreement with the simulation results.

scholarly journals Evaluation of Specific Absorption Rate in Three-Layered Tissue Model at 13.56 MHz and 40.68 MHz for Inductively Powered Biomedical Implants

2019 ◽  
Vol 9 (6) ◽  
pp. 1125 ◽  
Author(s):  
Krithikaa Mohanarangam ◽  
Yellappa Palagani ◽  
Jun Choi
Keyword(s):  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Printed Circuit Board ◽  
Input Power ◽  
Circuit Board ◽  
Power Transfer ◽  
Angular Misalignment ◽  
Specific Absorption ◽  
Measurement Results ◽  
Power Transfer Efficiency

This paper presents an optimized 3-coil inductive wireless power transfer (WPT) system at 13.56 MHz and 40.68 MHz to show and compare the specific absorption rate (SAR) effects on human tissue. This work also substantiates the effects of perfect alignment, lateral and/or angular misalignments on the power transfer efficiency (PTE) of the proposed WPT system. Additionally, the impacts of different tissue composition, input power and coil shape on the SAR are analyzed. The distance between the external and implantable coils is 10 mm. The results have been verified through simulations and measurements. The simulated results show that the SAR of the system at 40.68 MHz had crossed the limit designated by the Federal Communications Commission and hence, it is unsafe and causes tissue damage. Measurement results of the system in air medium show that the optimized printed circuit board coils at 13.56 MHz achieved a PTE of 41.7% whereas PTE waned to 18.2% and 15.4% at 10 mm of lateral misalignment and 60° of angular misalignment respectively. The PTE of a combination of 10 mm lateral misalignment and 60° angular misalignment is 21%. To analyze in a real-environment, a boneless pork sample with 10 mm of thickness is placed as a medium between the external and implantable coils. At perfect alignment, the PTE through pork sample is 30.8%. A RF power generator operating at 13.56 MHz provides 1 W input power to the external coil and the power delivered to load through the air and tissue mediums are 347 mW and 266 mW respectively.

Integrated in Clothes Graphene Antenna with Low SAR for Wearable Body-Centric Communications

2021 ◽  
Vol 15 ◽  
pp. 1657-1665
Author(s):  
T. N. Kapetanakis ◽  
C. D. Nikolopoulos ◽  
C. Petridis ◽  
I. O. Vardiambasis
Keyword(s):  
Graphene Sheet ◽  
Radiation Pattern ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Active Element ◽  
High Gain ◽  
Patch Antennas ◽  
Substrate Selection ◽  
Specific Absorption ◽  
Ism Band

The design and fabrication of graphene based textile patch antennas, intended for use in the 2.45GHz ISM band, are presented. The antennas have simple geometries with rectangular, triangular, or circular shape and substrate materials made of four different fabrics suitable for wearable applications. Conductive graphene sheet is used for the active element patches of the twelve different proposed prototypes. The effects of the antenna geometry, the substrate selection and the graphene-textile fabrication process on the prototypes’ performance are studied. Several prototypes exhibit desirable characteristics, such as high gain, acceptable radiation pattern, low Specific Absorption Rate (SAR), relatively wide bandwidth, and coverage of the ISM band even under different bending conditions.

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
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