| 講演抄録/キーワード |
| 講演名 |
2026-05-14 14:50
水中と海中の導電損を考慮した電磁波伝搬の過渡応答可視化と比較 ○白石迅人・菊川優希・丸山珠美(広島工大)・大宮 学(北大) MW2026-11 |
| 抄録 |
(和) |
近年、水中および海中の無線伝送に対するニーズが高まっている。しかし、水は比誘電率が81と大きく、理論上の波長は空中の1/9と大きな差が生じる。また導電率は、淡水で0.01(S/m)、海水で4(S/m)となり損失が極めて大きい。本研究では,これら水中、海中を想定した損失のある高誘電媒質と空気の境界に送受信ダイポールアンテナを置いて電磁界の広がりを、FDTDによる過渡応答によって示した。その結果, 淡水中では電磁波が
同心円状に広がり明瞭な干渉構造を形成するのに対し,海水中では導電損の影響により電磁波が送信点近傍で急激に減衰し,伝搬構造が大きく崩れることが確認された.特に,海水中では波動的な振る舞いから拡散的な挙動への遷移が見られ,電磁エネルギーが局所的に吸収される様子が明確に示された.また水中と空中の電磁波の広がりの差も明らかになった。 |
| (英) |
n recent years, the demand for wireless transmission in underwater and marine environments has been increasing. However, water has a high relative permittivity of approximately 81, resulting in a theoretical wavelength that is about one-ninth of that in air. In addition, its electrical conductivity is 0.01 S/m for freshwater and 4 S/m for seawater, leading to significant propagation loss. In this study, transient electromagnetic wave propagation was analyzed using the finite-difference time-domain (FDTD) method. A model consisting of transmitting and receiving dipole antennas placed near the boundary between air and a lossy high-permittivity medium representing freshwater or seawater was considered, and the spatial distribution of electromagnetic fields was visualized. The results show that in freshwater, electromagnetic waves propagate radially with clear interference patterns, whereas in seawater, the waves rapidly attenuate near the source due to conduction loss, resulting in a significant collapse of the propagation structure. In particular, a transition from wave-like behavior to diffusion-like behavior was observed in seawater, and the localized absorption of electromagnetic energy was clearly demonstrated. Furthermore, the differences in propagation characteristics, including spatial spreading and attenuation behavior, between air and water were also clarified. |
| キーワード |
(和) |
ワイヤレス電力伝送, / 過渡応答 / FDTD解析 / 水中無線伝送 / 誘電体中無線伝送, / 空間伝送型WPT / / |
| (英) |
Wireless Power Transfer (WPT) / Transient Response / FDTD Analysis / Underwater Wireless Power Transfer / Wireless Transmission in Dielectric Media, / Radiative WPT / / |
| 文献情報 |
信学技報, vol. 126, no. 24, MW2026-11, pp. 13-18, 2026年5月. |
| 資料番号 |
MW2026-11 |
| 発行日 |
2026-05-07 (MW) |
| ISSN |
Online edition: ISSN 2432-6380 |
著作権に ついて |
技術研究報告に掲載された論文の著作権は電子情報通信学会に帰属します.(許諾番号:10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
| PDFダウンロード |
MW2026-11 |
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