Research On Key Technologies Of Simultaneous Wireless Information And Power Transfer Based On Holographic Metasurface

With the rapid development of mobile communications,the number of radio devices has exploded.For many appliances that are difficult to wire,the traditional power supply method cannot meet the demand,significantly limiting communication networks’ development.The emergence of wireless power transfer(WPT)technology provides a new solution to solve the above problems.However,wireless communication technology and wireless power transfer technology have developed independently.Electronic devices are becoming more and more miniaturized and highly integrated into today’s society.Therefore,there is an urgent need to combine the two technologies organically,and simultaneous wireless information and power transfer technology has emerged as the times require.Since the concept was proposed in 2008,it has attracted extensive attention from scholars at home and abroad.This thesis explores and researches new forms of simultaneous wireless information and power transfer based on holographic metasurfaces.The specific work of this thesis is as follows:1.Design of a holographic metasurface transmitter based on polarization diversity.Firstly,the basic idea of realizing the simultaneous and cooperative transmission of power and information through polarization diversity is proposed,and the multi-target field of the holographic metasurface is studied and analyzed from the perspective of power.Then different designs are carried out for three different scenarios.For far-field simultaneous wireless information and power transfer,a holographic metasurface with dual-polarization distribution to generate dual-polarization high-gain beams is designed,and the gain of the two polarizations can be flexibly controlled to realize the separation of power and information and complete the power distribution.Then,for near-field simultaneous wireless information and power transfer,a holographic metasurface is designed to generate zero-order Bessel beams based on polarization diversity to achieve power-information separation and complete power ratio.Furthermore,this thesis proposes two optimal design schemes based on partitioning,so that the power distribution on the beam path is more uniform.Finally,two different polarizations are designed for the separated receiver architecture where the energy receiver and the information receiver are located in different positions.One is intended to be a focused beam for efficient wireless energy transmission,and the other is designed for high Gain beams used for long-distance communication.2.Research on rectify-communication dual-polarization receiving metasurface.Corresponding to the transmitting modules mentioned above,we design a dual-polarization metasurface as a receiver based on a ring element with branch nodes.The operating frequency is 5.8 GHz,which can efficiently collect electromagnetic energy in space.Then a high-efficiency rectifier circuit is designed,and a wide dynamic range rectifier circuit design is realized through a new single-node impedance compression network.The highest rectifier efficiency measured is 71.3%.At the same time,the influence of modulated waves generated by several common digital modulation methods on the rectification efficiency is analyzed by experimental methods,the QPSK modulated wave has the most negligible impact,and the rectification efficiency is higher as the bandwidth decreases.Finally,the rectifier circuit is miniaturized and integrated with the dual-polarization metasurface to obtain a rectifycommunication dual-polarization receiving metasurface for simultaneous wireless information and power transfer.3.Analysis and verification of simultaneous wireless information and power transfer system based on holographic metasurface.The main content of this chapter is to build a simultaneous wireless information and power transfer system using the transceivers designed above and verify its performance.Firstly,a communication system based on QPSK modulation is built using Usrp.The simulation analysis and system experiment of the farfield single-target simultaneous wireless information and power transfer system is carried out.The experiment realized the simultaneous transmission of power and data.It proved the feasibility of using the holographic metasurface to realize simultaneous wireless information and power transfer based on the idea of polarization diversity.At the same time,a multitarget simultaneous wireless information and power transfer system is built by using a holographic metasurface that generates zero-order Bessel beams.The detailed simulation analysis and experimental tests are carried out from the three dimensions of the receiving metasurface’s aperture size,target distance,and target number.The results are good,and the multi-target energy-carrying communication that lights up multiple LED lights while transmitting pictures is finally realized.In summary,the thesis proposes the basic idea of polarization diversity for simultaneous transmission of wireless information and energy,which uses the holographic metasurface as the transmitter to transfer energy and information through polarization diversity collaboratively.The design of the rectify-communication receiving metasurface achieves single and multiple targets simultaneous wireless information and power transfer system,providing a new method to realize the separation of power and information by using polarization in the spatial dimension based on holographic metasurface.