Multiple-Resonator Wireless Power Transmission System Design and Integrated Data Path

摘要

With the rapid development of mobile and implantable devices, the wireless power transfer (WPT) technology has become increasingly attractive because it frees numerous electronic systems from power cords or batteries. Recently, the WPT method based on the magnetic resonant coupling has gained popularity both in research and applications. This dissertation contributes to the magnetic resonant WPT system design by addressing three important problems.ud udThe first problem deals with the design of multiple-resonator systems. In order to power objects over a longer distance, a multiple-resonator system is usually needed. However, most existing multiple-resonator systems are designed experimentally with a strict requirement on the position of the resonators. We propose to optimize multiple-resonator systems by investigating the transfer function from the transmitter to the receiver. An equivalent circuit model is developed to maximize the power output. This method is then utilized to find the optimal position for the relay resonator in a three-resonator wireless power transfer system.ud udThe second problem is to power a device which is mobile within a certain field. The Biot-Savart law and a concentric model of a spiral coil are utilized to simulate the magnetic field distribution of a multiple-transmitter WPT platform. The vertical component of the magnetic field of the coil is optimized to achieve an evenly distributed magnetic field over the field. As a result, a position-free powering of mobile sensors or devices is achieved. ud udThe third problem deals with integration of wireless power transfer and wireless data communication. This problem is especially importation in implanted medical sensors where power must be delivered to the implants and measured data must be transmitted to the outside of the human body. Currently, most implementations of power and communication systems utilize a separated data channel, which requires not only substantial power consumption but also a high complexity of the implanted circuit. In this work, a unified data and power channel is developed in which data are processed by an asynchronous sigma-delta pulse conversion. The resulting pulses are transmitted using load modulation.ud