AWPT 2022 Asian Wireless Power Transfer Workshop December 5–6, 2022 | Kyoto, Japan

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Keynote Talk 1:
Fundamentals of Meta-Tx: A Metamaterial-Assisted Tx for Compact WPT System for Wireless Charging of Implants

Dr. Ramesh Pokharel
Kyushu University, Japan


Wireless charging of biomedical implants will make the life of patients with implants much easier. However, it is associated with significant design challenges - efficiency degradation and the need to meet standards for exposure to electromagnetic fields. Tissue's dielectric and conductive properties affect the electrical performance of an inductor, which appears on increased effective inductance, reduced quality factor, and reduced self-resonance. Building a wireless power transfer (WPT) system using such inductors leads to low efficiency and low power that limit specific absorption rate. In this work, we will introduce the characteristics of inductance in biomedical tissue and its problems. Finally, to overcome these issues, we propose a metamaterial-assisted geometry for transmitter side, called meta-Tx. The effects of losses of metamaterial and their design approach will be disused in detail in this lecture.

  • R. K. Pokharel, A. Barakat, S. Alshhawy, K. Yoshitomi, and C. Sarris, “Wireless power transfer system rigid to tissue characteristics using metamaterial inspired geometry for biomedical implant applications,” Sci. Rep., vol. 11, pp. 1–10, 2021.
  • S. Alshhawy, A. Barakat, R. K. Pokharel, and K. Yoshitomi, “Low Magnetic Loss Metamaterial Based Miniaturized WPT System for Biomedical Implants” Dig. of 2022 IEEE IMS, June, 2022.
  • Biography

    Ramesh Pokharel received the M.E. and Doctorate degrees from the University of Tokyo, Japan in 2000 and 2003, respectively all in electrical engineering. After spending as a post-doctoral research fellow with Aoyama Gakuin University for two years from 2003 to 2005, he joined Kyushu University in 2005, where he is a professor now. His current research interests include the low-cost RFIC and analog circuits for microwave and millimeter-wave wireless communications and metasurface/metamaterial-inspired geometries for simultanous wireless information and power transfer (SWIPT) systems for sensing and biomedical applications.

    Dr. Pokharel was a recipient of the Monbu-Kagakusho (MEXT) Scholarship of the Japanese Government from 1997– 2003, an excellent Center of Excellence (COE) research award from the University of Tokyo in 2003, the 2016 best ELEX Paper Award from the IEICE Japan, WPT Competition Awards in 2019 and 2021, and a few more with the students he has supervised.