Research Of The Energy Harvesting Technology For Wireless Energy Transmission

In recent years,with the development of the wireless communication technology,people's life is changing.And the satellites,drones,medical implantable devices,shared bikes and so on,are all developed because of the wireless technology.There is a new problem that how to supply power for the wireless sensors.The wireless technology not only changes people's life and work,but also promotes itself.Wireless technology can carry information in communication.And it can also be applied to transmit energy without carrying information,which is named wireless power transmission(WPT).WPT provides a convenient and efficient solution to the power problem.This thesis presents two technology of the energy harvesting in WPT.One is the rectenna,and another is the metasurface for energy harvesting.Firstly,the theis introduces the status quo of the WPT.The second part is about the research of the fundamental theory of the rectenna and the energy harvesting metasurface.The rectenna is consisted of the receiving antenna and the rectifying circuit.Rectenna can receiving the microwave power and convert it to DC power.The efficiency of the rectenna mostly depends on the efficiency of the rectifying circuit.It is significant to choose an appropriate rectifying diode and design the matching and filter circuit.The third part is about the simulation design of the 2.4GHz rectenna.The rectenna is consisted of the rectifying circuit with the efficiency of 84.5% and the antenna with the harmonic suppression.Through the wireless power transmission experiment,we have lighted the LED tube of the rectenna.The fourth part focuses on the design of the energy harvesting metasurface.Based on the theory of the absorb metamaterial,the absorb efficiency of the metasurface is 87.5%.And it can convert AC energy into DC energy through the lumped diodes with the efficiency of 37.1%.Comparing with the rectenna,it does not need a complex matching circuit and has the characteristic of the polarization insensitivity.Finally,this thesis summarizes and prospects our work done.