Low-power dual-band on-body antenna for wireless body sensor networks

Farghaly Sayed, SM

Abstract

In Wireless Body Area Network (WBAN), the implanted biosensor collects various physiological data and wirelessly transmits the information to external medical devices in real time. The antenna design for this application faces great challenges as the microwave
propagation medium is not the free space as the human tissues constitute part of the transmission channel. The effects of the human body should be taken into consideration during the antenna
design.
The present thesis aims to arrive at the optimum design of the on-body antenna to operate as a central antenna for WBAN. Five types of helical antennas are proposed in the present thesis
having a dual-frequency operation at 2.45 GHz and 5.8 GHz. The proposed antennas are optimized to maximize the Signal-to-Noise-Ratio (SNR) and, hence, to minimize the BER and the Specific Absorption Rate (SAR) in the human tissues. In this thesis, a semi-analytic rigorous technique for the assessment of microwave propagation on the medium equivalent to the human body is developed and the radiated fields from the proposed on-body antennas in the near zone are evaluated.
The commercially available CST® simulator is used and experimental measurements are done for the five fabricated prototypes. The near-field distribution over the surface of human
body is evaluated at 2.45 GHz using a Matlab® program, while the far-field radiation patterns obtained by experimental measurements showing good agreement with those obtained by the CST® simulator. It is shown that the radiation patterns produced by the more compact antennas; the conical-helix monopole and the monopole-spiral antennas show better performance and more
appropriate for the intended application.
It is clear from the obtained results that the conical-helix/monopole and the monopole-spiral antennas have the highest performance. These antennas are shown to achieve the minimum BER
of 5.3 × 10-5 and 6× 10-8 for both antennas respectively. In addition, the minimum average of the SAR that does not exceed 0.3 W/Kg in the human tissues while consuming the minimum value
of the input power when compared with the other antenna types.

Citation

Farghaly Sayed, S. Low-power dual-band on-body antenna for wireless body sensor networks. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Nov 9, 2021
• Publicly Available Date: Nov 9, 2021
• Additional Information: Funders : Arab Academy for Science, Technology and Maritime Transport
• Award Date: Sep 26, 2020