Power Synthesis Optimization Method of Microwave Rectifying Antenna Array with Non-Uniform Power Distribution
Microwave wireless power transmission(MWPT)utilizes microwave radiation to realize long-distance wireless power transmission,a subversive power transmission technology with potentially broad application prospects.The receiving end includes a large-scale receiving array antenna,rectifier module,and power synthesis.At present,the research on receiving antenna and rectification technology has made some progress,but the research on power synthesis is inadequate.There are two main ways of power synthesis:DC and RF.Due to the inherent characteristics of microwave long-distance transmission,the radiated power distributed on the large-scale receiving array antenna needs to be uniform.Suppose one single power synthesis method is used.In that case,inappropriate rectifier input causes issues such as the rectifier working incorrectly,the rectification efficiency being low,and the load being mismatched,which seriously affects the transmission efficiency of the energy transfer system.This paper proposes a new hybrid power synthesis method with the genetic optimization algorithm.Firstly,the input-output characteristics of the rectifier with Schottky diode are analyzed.The input power-conversion efficiency characteristic curve of the rectifier is derived,and the optimal input power corresponding to the optimal conversion efficiency,i.e.,the target power for RF synthesis,is determined.Next,chromosome coding rules are proposed to interconnect receiving antenna units.A power synthesis correlation matrix and uniformity evaluation indices are established.According to the target power,the receiving antenna units are dynamically grouped and synthesized with RF,which ensures microwave power homogenization across each group post-RF synthesis.Furthermore,coding rules for the rectifier circuit interconnection are devised.The rectifiers are dynamically optimized for series-parallel connection with the goal of load matching,thus achieving optimal conversion efficiency post-DC synthesis.A MWPT simulation system is constructed.A 10×10 array of receiving antenna arrays is utilized,with a total RF power input of 166.7 mW.Four channels of RF power output are obtained with a uniformity evaluation index(εr)of 1.804 using the grouped RF synthesis uniformization method.In contrast,direct RF synthesis with 100 channels yields an εr of 126.7.Following optimization through load-matching DC synthesis,an energy conversion efficiency of 91.37%is achieved,while the pure series and pure parallel DC synthesis methods are 58.89%and 22.81%,respectively.The proposed hybrid power synthesis optimization method can significantly enhance the transmission efficiency of long-distance MWPT systems.
Microwave wireless power transmissioncombined power synthesiscode ruledynamic series-parallel optimizationproperties of the rectifier circuit
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