Design And Implementation Of Wireless Power And Information Synchronous Transmission System Based On Magnetic Resonance Coupling

Wireless Power Transfer(WPT) technology which can make energy transfer without any physical contact is more flexible and convenient, and it has a very wide range of application prospects in the power supply of mobile devices. However, in many applications, such as smart ammunition, implantable devices, sensor networks, RFID(Radio Frequency Identification) and other fields, we also need to transfer control commands and receive feedback information at the same time of transmitting energy. Meanwhile there will be some challenges like the interference between energy signal and communication signal, the decrease of the wireless transmission power and incapability of full duplex communication in the synchronous transmission of power and information.This thesis is based on the focus project of Chongqing Municipal Science and Technology Commission for application and development "The key technology and design of RFID system in the complex metal environment", which mainly focuses on the research of wireless power transmission technology and the synchronous transmission technology of power and information. For the application of a special dynamic environment, this thesis designed and implemented a set of wireless power and information synchronization transmission system which is in accordance with the requirements of this project.In a dynamic environment, the optimal resonant frequency will deviate from the natural frequency of the system. In order to solve this problem, this thesis uses the Royer oscillator with adaptive tracking ability of the resonant frequency of the system to design wireless power transmitting circuit based on magnetic resonant coupling. Then, some improvements are made about original driving circuit, which greatly decrease the system loss and dimension, also improve the power and efficiency of wireless power transmission. In addition, the transmitter can also be more convenient to increase the power of wireless power transmission, especially in high power wireless power transmission.In order to realize the synchronous transmission of power and information, the power signal is used as the communication carrier to implement the 2FSK(Binary Frequency Shift Keying) modulation. Meanwhile, a very simple 2FSK demodulation scheme is designed to realize the transmission of downlink communication. Furthermore, two kinds of dual-band resonator schemes are designed to solve the problem of wireless power reduction caused by 2FSK modulation, which principle is to keep the resonator resonant at the two frequency points of the power signal. Without additional communication signal transmission channel, the modulation of uplink communication is realized by controlling the load impedance of the receiver, and demodulation is realized by detecting the current amplitude change of the wireless power transmitting circuit at the transmitter end. The downlink communication does not interfere with the uplink communication with the implementation of dual-band resonator schemes scheme, so the system can realize full duplex communication.Finally this thesis gives the experimental verification and analysis of the wireless power and information synchronization transmission system based on magnetic coupling resonance, the results show that the system can give a good accomplishment of the default targets.