Design Of Reflector Array Transmitting Antenna For Microwave Wireless Power Transmission

Wireless power transmission(WPT)gets rid of the restriction of cables,so it makes the transmission of electrical energy more flexible and convenient.As a kind of WPT,microwave wireless power transmission(MPT)has great development potential and broad application prospect because it can realize high-power and long-distance power transmission.At present,there are two common transmitting antennas in microwave wireless power transmission.They are reflector antenna and active phased array antenna.But both of them have own shortcoming in the case of large aperture,so the reflector array antenna is proposed as transmitting antenna in order to make up for their respective shortcomings.For the microwave wireless power transmission system,the design of the transmitting antenna is very important.This thesis is mainly concerned with the design of high beam collection efficiency of reflector array antenna,and the design of flat top beam of reflector array antenna.The major contribution of the author on these subjects can be summarized as follows:1.Electromagnetic analysis of reflector array antenna for power transmission.Firstly,the calculation formula of far-region radiant electric field of reflector array antenna is derived on the basis of the knowledge of array antenna and reflector antenna.Then,the gain pattern of the antenna with different feed source,focal diameter ratio,element aperture,element spacing and element spatial direction is obtained on the basis of the formula of electric field.The simulation results show that three aspects are very important in order to ensure the reflector array antenna has high beam collection efficiency.They are the optimal field distribution on the aperture surface of reflector array antenna,no element spacing between the adjacent reflector element and no space pointing offset of the reflector elements respectively.2.Design of reflector array antenna for maximum beam collection efficiency.Firstly,the aperture relation of transceiver antenna in microwave wireless power transmission is discussed.Next,three design elements related to the design of reflector array antenna are determined on the basis of the theory of array antenna and the electromagnetic analysis of reflector array antenna.They are array arrangement,array excitation amplitude and field distribution on aperture surface respectively.Then,the formula for calculating the beam collection efficiency is given,and the relationship between the three design elements and the beam collection efficiency of reflector array is analyzed.Finally,the design method of reflector array antenna with high beam collection efficiency is defined from the relationship.3.Flat top beam design of reflector array antenna based on phase weighting.Firstly,the phase weighting are introduced.Then,the mechanism and influence of phase weighting are studied.What’s more,the changes of electromagnetic characteristics of antenna after phase weighting are analyzed.Finally,a phase weighted optimization model is established to obtain the flat-top beam,and the optimization model is solved by the particle swarm optimization algorithm.Here,the numerical results verify the correctness of the optimization model and the effectiveness of the flat-top beam design method.