Electric characteristics of very small normal-mode helical antenna in human body conditions

2017 International Conference on Advanced Technologies for Communications (ATC) ◽

10.1109/atc.2017.8167645 ◽

2017 ◽

Cited By ~ 1

Author(s):

Dang Tien Dung ◽

Nguyen Quoc Dinh ◽

Yoshihide Yamada ◽

Naobumi Michishita ◽

Ha Quoc Anh

Keyword(s):

Normal Mode ◽

Human Body ◽

Helical Antenna

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Simulation methods of a normal-mode helical antenna in a human body condition

2016 International Conference on Advanced Technologies for Communications (ATC) ◽

10.1109/atc.2016.7764810 ◽

2016 ◽

Cited By ~ 1

Author(s):

Dang Tien Dung ◽

Nguyen Quoc Dinh ◽

Nguyen. T. Tuan ◽

Yoshihide Yamada ◽

Naobumi Michishita

Keyword(s):

Normal Mode ◽

Body Condition ◽

Human Body ◽

Simulation Methods ◽

Helical Antenna

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Increase of Input Resistance of a Normal-Mode Helical Antenna (NMHA) in Human Body Application

Sensors ◽

10.3390/s20040958 ◽

2020 ◽

Vol 20 (4) ◽

pp. 958 ◽

Cited By ~ 2

Author(s):

Norsiha Zainudin ◽

Tarik Abdul Latef ◽

Narendra Kumar Aridas ◽

Yoshihide Yamada ◽

Kamilia Kamardin ◽

...

Keyword(s):

Normal Mode ◽

Human Body ◽

High Performance ◽

High Efficiency ◽

Input Resistance ◽

Resonant Mode ◽

Helical Antenna ◽

Antenna Structure ◽

Electromagnetic Simulations ◽

Physical Reasons

In recent years, the development of healthcare monitoring devices requires high performance and compact in-body sensor antennas. A normal-mode helical antenna (NMHA) is one of the most suitable candidates that meets the criteria, especially with the ability to achieve high efficiency when the antenna structure is in self-resonant mode. It was reported that when the antenna was placed in a human body, the antenna efficiency was decreased due to the increase of its input resistance (Rin). However, the reason for Rin increase was not clarified. In this paper, the increase of Rin is ensured through experiments and the physical reasons are validated through electromagnetic simulations. In the simulation, the Rin is calculated by placing the NMHA inside a human’s stomach, skin and fat. The dependency of Rin to conductivity (σ) is significant. Through current distribution calculation, it is verified that the reason of the increase in Rin is due to the decrease of antenna current. The effects of Rin to bandwidth (BW) and electrical field are also numerically clarified. Furthermore, by using the fabricated human body phantom, the measured Rin and bandwidth are also obtained. From the good agreement between the measured and simulated results, the condition of Rin increment is clarified.

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