Research On Technology Of Microwave Wireless Charging Circuit

With the development of electronic communication technology,the Requirements for the performance of electronic equipment are getting higher and higher.New technologies such as mobile Internet and Internet of things(IoT)are developing vigorously.As a form of wireless energy transmission,wireless charging was studied more and more in the fields of low power consumption,multi-node,bad working environment and other electronic systems.Therefore,the research of microwave wireless power transmission(WPT)with high performance is of great significance.In this paper,the broadband rectifiers and duplex antennas are studied as follows:1.The structure of the microwave wireless charging system is analyzed.The efficiency of transmission is deduced theoretically.The performance index of each part of the circuit is introduced.The limitation factors of the bandwidth of rectifier circuit are analyzed and simulated.The methods of widening the bandwidth of rectifier circuit are summarized.The characteristics of duplex antenna are introduced,and the advantages of duplex antenna in the field of microwave wireless power transmission are innovatively explained.2.Based on the traditional narrowband rectifier circuit with filter-match-rectifier-filter structure,a rectifier circuit architecture with arbitrary bandwidth based on multiplex combining mechanism is proposed,which greatly expands the bandwidth of rectifier circuit without affecting efficiency.Based on this idea,a dual-channel broadband rectifier circuit working at 1.5GHz-2.5GHz is designed.The measured results show that the rectification efficiency is basically 60%.The filter structure of this circuit is improved,and a miniaturized broadband rectifier circuit is designed by using the common input filter structure.3.Based on the traditional planar printed dipole antenna,a new feeding port is added to realize miniaturization by converting it to a monopole antenna.The duplex antenna with simulated isolation of 1.5GHz-2.5GHz and 5.6GHz-5.95 GHz is realized by adjusting the whole structure.A miniaturized filter structure is added to the feed port.With almost the same size,the measured return loss is greater than 12.5dB with corresponding port,and the measured isolation between the ports is greater than 30 dB in the working frequency.The filtering duplex antenna and the miniaturized broadband rectifier circuit are cascaded.The microwave wireless charging receiving system is obtained and measured.In order to improve the pattern characteristics duplex antenna at high frequency,a dual-frequency reflector based on artificial magnetic conductor(AMC)technology is designed,which greatly improves the pattern characteristics of high frequency antenna when the bandwidth of low frequency band is reduced.