The Influence of HF Wireless Power Transmitter on nearby Thin-Wire Objects: A Simplified Analytical Model

Wireless power transfer system performance is determined by the antenna’s radiation effectiveness and operational resonant frequency. In high-frequency wireless power transfer systems, surrounding objects influence antenna characteristics and, as a result, wireless power transfer system performance. In this paper, the interaction of thin, lossy wire objects with wireless power transmitters is investigated. A small electric dipole transmitter antenna and a lossy wire at a near distance are modeled using analytical and numerical methodology. The study is performed in terms of induced current along the wire at 13.56 MHz for a lossy thin wire placed in free space and subjected to high-frequency radiation. The analytical technique entails deriving the approximate sinusoidal current distribution and analyzing field integrals. Analytical results are tested using numerical simulations in the commercial program 4Nec2. It is demonstrated that that the difference between the findings by the methodologies investigated in the paper are only moderate. Thus, the proposed approximate analytical method can be very useful in practice for fast estimations of the electromagnetic compatibility.