| With the development of modern equipment and the gradual exhaustion of traditional energy sources,solar energy as a new energy source has attracted much attention.Solar energy in space is an ideal energy choice due to its many advantages.Mankind expects to fully develop and utilize solar energy.Therefore,the establishment of space solar power stations is an effective way to solve the problem of energy depletion,that is,through Solar Power Satellites(SPS)It receives solar energy in space and converts it into electrical energy,and then uses Microwave Wireless Power Transmission(MWPT)technology to transmit it to the earth for human use by microwave.As the key to space solar power stations,microwave wireless energy transmission has always been a hot research direction at home and abroad.This thesis is based on the "Daily Project" project of Xidian University and the Shaanxi Provincial Government to optimize the efficiency of the microwave wireless energy transmission and collection system,from the three aspects of receiving array antenna,rectifier circuit and terminal DC synthesis Start the research,the main work is as follows:Firstly,The design of the receiving antenna array.First,the aperture surface of the receiving antenna is divided into three areas of red,orange and yellow based on the power density distribution,and three corresponding left-handed circularly polarized air microstrip antennas with different gains are designed.They are a single antenna unit module in the red area and1x2 array antenna unit module in the orange area and 2x2 array antenna unit module in the yellow area.Secondly,the three antenna modules are simulated,processed and measured.The actual measurement results show that the single antenna unit gain is 8.59 d Bic and the axial ratio is 1.22 d B;the 1x2 array antenna unit gain is 11.11 d Bic and the axial ratio is0.85 d B;2x2 The gain of the array antenna unit is 13.32 d Bic,and the axial ratio is 1.01 d B,which meets the design requirements of the three antennas.Finally,test the standing waves of all antennas and the axial ratios of some antennas in this project,and the results obtained meet the requirements.Secondly,Design of high-efficiency rectifier circuit.First,the structure of the rectifier circuit and the model of the diode were selected,and an equivalent circuit model of the diode was built.Secondly,the simulation analysis of each part of the rectifier circuit is carried out,and two band-stop rectifier circuits based on different pass filters and matching networks under high input power range are designed.By comparing the measured efficiency and the circuit size,the first one is selected.Adopting a stub structure of a through filter and a band-stop rectifier circuit of a single-segment matching network,designing the circuit through the HFSS matching network and adopting the improved method of adding a ground shielding hole,the input power can be obtained when the input power is 26 d Bm and the load is 420Ω,The rectification efficiency is 61%.Using the same design method for low input power,the rectification efficiency is 60.8% when the input power is 18 d Bm and the load is 150Ω.Finally,a total of 7,200 rectifier circuits with high and low input power were measured one by one,and the efficiency was above 60%.Thirdly,DC synthesis of the rectifier circuit terminal.First,the ideal power supply is equivalent to the rectifier antenna,and the principle of series-parallel connection of multiple rectifier circuits is given.Secondly,the rectenna arrangement is divided into quadrants,and the series-parallel principle is used to complete the synthesis of each quadrant and the quadrants.Finally,the DC output power of the receiving antenna system can be calculated to be 830.08 W,and the series-parallel efficiency is 85.01%.Finally,the layout design of the DC synthesis is carried out,and the DC synthesis efficiency test of the rectifier antenna array is carried out.The overall commissioning of the microwave wireless energy transmission system is underway. |
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