A Research Of Wireless Power Transmission Based On Magnetic Coupling Resonance

Since the twentieth century, with the rapid development of science and technology, the medical field also is in fast development. Recently, the world economy increases at an stable rate, people’s requirements in the medical field also are on the increase, especially in the costly medical equipment, such as the implanted devices. But implanted devices have a defect that is the battery life can’t match the patient’s requirements. If the device’s battery runs out during the device is in use, the patients have to make the choice of taking surgery to replace the equipment, and the surgery will bring more pain and economical burden. To sloved this problem, we can supply the energy to the implanted devices, such as cardiac pacemaker and Deep Brain Stimulator(DBS), by the magnetic resonant wireless power transmission technology.The magnetic resonant wireless power transmission technology has the characteristics of far transfer distance, high efficiency and insensitive of the position between the coils, it is more suitable for the mid-range wireless power transmission, such as the above application background. The system of the magnetic resonant wireless power transmission consist of the waveform generator, the power amplifier, the resonant coils and the rectifier, and the design of the resonant coils and the power amplifier are the key point of the system. In this thesis, firstly, studies the relation between the electronic characteristics and the physical size of the coils on the PCB(Printed Circuit Board); then for the different operating frequency of ISM(Industrial Scientific Medical) band, calculate the physical size of coils which has a better performance of the resonant coils by using mathematical analysis method, and verify the reliability of the calculation by simulation; thirdly, by comparing the simulation result, chose a better performance band as the operating frequency of this subject; fourthly, by theoretical analysis, simulation and optimization, design a high efficiency inverse class E power amplifier; finally, design the middle matching network between the power amplifier and the resonant coils, the output matching network between the output port and the resonant coils and the input matching network between the input port and the power amplifier to realize the energy transfer efficiently in this system.By adding the model of the actual device to the simulation schematic, the result of the power amplifier is that the output power is 37.70 dBm, the PAE(power added efficiency) is 73.65%, the power gain is 27.70dB; Combined the resonant coils, the simulation result of the whole system is that the output power is 34.90 dBm, the PAE is 40.81%, the power gain is 24.90 dB, the input return loss is-22.19 dB and the output return loss is-11.63 dB, and basically meet to the requirements of the default indicators. Then fabricating the circuits by the PCB of the FR4 dielectric, and do the experiment test by adding the animal issues to the gap between the coils, the result verify the feasibility of the wireless power transmission technology apply to the implant devices.