Conditions of maximum efficiency for wireless power transfer between two helical wires

Author

Moshfegh, J. ; Shahabadi, Mahmoud ; Rashed-Mohassel, Jalil

Author_Institution

Center of Excellence on Appl. Electromagn. Syst., Univ. of Tehran, Tehran, Iran

Volume

5

Issue

5

fYear

2011

fDate

4/1/2011 12:00:00 AM

Firstpage

545

Lastpage

550

Abstract

The effects of loading and transmission distance on the efficiency and the input impedance of a wireless power transfer system composed of two helical wire antennas are investigated in detail. These antennas operate in their non-radiative near-field region. The method of moments (MoM) full-wave simulation in FEldberechnung bei Körpern mit beliebiger Oberfläche (FEKO) is used to determine current distribution on this wire structure. The conditions of maximum efficiency for mid-range (0.1̈) wireless power transfer are studied for various load resistances. It is found that the wireless power transfer efficiency is a maximum for the values of the load resistance in the range of 330̈400̈̈, for transmission distances up to 3.3 times the transmitter size with a base radius of 0.01̈. To improve the power transmission efficiency, a ̈repeater̈ helical structure is introduced. This helical structure improves the efficiency up to 35̈ in a transmission distance of 0.1̈.

Keywords

antenna radiation patterns; current distribution; method of moments; FEldberechnung bei Korpern mit beliebiger Oberflache; MoM full-wave simulation; current distribution; helical wire antennas; loading-transmission distance; method of moments; resistance 330 ohm to 400 ohm; transmission distance; wireless power transfer system;

fLanguage

English

Journal_Title

Microwaves, Antennas & Propagation, IET

Publisher

iet

ISSN

1751-8725

Type

jour

DOI

10.1049/iet-map.2010.0134

Filename

5766082