| In recent years,there are more and more scholars studying microwave power transmission system,and the research results are rich.However,there are still many problems in microwave transmission system,such as low transmission efficiency and short transmission distance.Electromagnetic metamaterials are a kind of important manmade materials,which are composed of sub wavelength unit cell arrays(also known as super atoms).After design,they will have some characteristics that can not be achieved by natural materials,such as negative permittivity and negative permeability.The response of metamaterials mainly depends on the structural design of the cell,rather than its chemical composition.Therefore,many attractive applications have been realized in the design from low frequency to high frequency(including microwave to terahertz)due to its unprecedented performance.The microwave power transmission system mainly integrates metamaterials in the antenna,so that the directivity and gain of the antenna can be improved,and the most effective way is to use metamaterials Finally,the efficiency of the rectifier circuit is improved.Therefore,the use of metamaterials can perfectly improve the efficiency of wireless transmission.In this paper,we first introduce the applied principles,including metamaterials,microstrip antennas and Fabry Perot resonators,and then introduce the left-handed materials.In the part of wts,the transmitter transmits converts the AC energy into DC energy through rectification and other steps,and finally supplies it to the back-end load.This paper will verify the effectiveness of the proposed method through three parts:theoretical analysis of antenna and rectifier circuit,simulation experiment and physical production and test.In the part of antenna,the principle of Fabry Perot resonator will be used.The Fabry Perot resonator is realized through the reflection characteristics of lefthanded materials.The RF simulation software HFSS will be used to design the auxiliary antenna.Finally,a new type of metamaterial antenna with "MI" shape structure will be designed.The simulation results show that the model studied in this paper has a good effect,which can significantly improve the gain and enhance the performance of ordinary microstrip antenna.Next,the rectifier circuit module of the receiving antenna is designed.First,the class-F structure rectifier circuit is selected.In the aspect of simulation,ads is selected.The Schottky diode hsms282 c has good performance in the case of low power input.This paper makes some designs.Finally,the microwave power transmission system is made into a physical object,first integrated and finally tested.The test results show that when the input is 20 dbm,the rectification efficiency of the 2.45 GHz Class F rectifier circuit reaches 65%,which verifies the feasibility of the design.Finally,a complete microwave power transmission system based on metamaterials is designed and built,and the influence of several parts of the system is fully considered.In the test,the output performance of the whole system in the near field is tested first,and then the output effect of the system in the far field is tested,and further compared with the standard horn antenna.It is concluded that compared with the traditional wireless transmission system,the output power,output voltage and transmission efficiency of the system are significantly improved when loaded with metamaterials. |
