Resonant Wireless Power Transmission Research Articles

Data Transmission Using Original Coils in Resonant Wireless Power Transmission

We propose a data transmission method for resonant wireless power transmission systems. In order to transmit data, we use the coils originally designed for power transmission, no additional antennas are required. We focus on uplink data transmission and adopt the load modulation technique. This configuration yields mid-range data transmission without transmitting power. In addition, the proposal enables simultaneous power feeding and uplink data transmission. We make a prototype demonstrating resonant wireless power transmission and measure its S-parameter under some load conditions. The results confirm the potential of load modulation in supporting uplink data transmission. Additionally, the results are elucidated by analyzing an equivalent circuit. Measured S-parameter and equivalent circuit response are found to be similar.

Numerical Analysis on Transmission Efficiency of Evanescent Resonant Coupling Wireless Power Transfer System

A practical wireless power transmission system consisting of a large rectangular wire loop and a small square wire loop with a parasitic square helical coil is proposed for use as an efficient evanescent resonant coupling wireless power transmission system in an indoor environment. In addition, a full wave-based numerical analysis on the resonant frequency of and the power transmission efficiency of wireless power transmission system are performed in this paper. The effects of the following on power transmission efficiency and the resonant frequency are numerically investigated: The load of the receiving element and the presence of non-resonant objects such as a conducting box or human body. The numerical results show that a power transmission efficiency of nearly 50% can be achieved when the proposed system is used to charge only one user with the optimized load. The results also show that power transmission efficiency is reduced significantly when a human body is in very close proximity to the receiving element. This reduction in efficiency can be alleviated significantly, however, if the relative distance between the receiving element and the human body is greater than 0.5 m or 0.03? at a resonant frequency of 19.22 MHz.