Research On Rectenna Technology For Microwave Power Transmission Applications

With the continuous development of microwave power transmission(MPT)technology,its application is no longer limited to the research of space solar power stations,but also gradually applied to daily production and life,such as wearable devices,electric cars and drones with wireless charging function,etc.At the same time,in response to the country’s strategy of strengthening the military through science and technology,MPT has also developed rapidly in microwave weapons and microwave combat equipment.MPT technology has greatly promoted the development of the economy and society,and it has huge application prospects and research value.The rectenna plays a very important role in the MPT system,and it is one of the focuses of research in the field of MPT.Based on the investigation of the development history and accomplishments of rectenna technology at home and abroad,and the analysis of future development trends,key issues such as rectification efficiency,miniaturization and integration of rectennas in different application scenarios are researched in this paper.It has achieved certain research results,and the main work contents are as follows:First,based on the transmission line theory,the topological structures of 5.8 GHz and 433 MHz rectifier circuits are established respectively.By reconstructing the equivalent circuit package model of diode and importing the actual capacitor and inductor package model,a more accurate diode circuit input impedance can be obtained.The single-segment microstrip structure and the L-shaped lumped parameter structure are used to perform impedance matching on the two circuits respectively.The feasibility of designs is verified by tests.It is measured that when the input power is 17 d Bm and11 d Bm,the rectification efficiency reach 60.71% and 77.8%,respectively.Then,based on the fundamental theory of antenna,a 2.45 GHz rectangular microstrip patch antenna unit and an 8×8 array antenna,a 5.8 GHz sector-shaped differential microstrip antenna unit,a 2×2 array antenna and an integrated rectenna,and a dual-polarization filtering antenna unit are proposed in this paper.Great directional radiation characteristic is achieved and they can be used as receiving antennas in different application scenarios.Finally,MPT experimental systems are established.The red LED light in the 5.8GHz differential microstrip patch rectenna array is lit,and the system successfully realizes microwave rectification.When the transmission distance of the 433 MHz experimental system is 2.5 m,the rectification efficiency can reach up to 75.6%,and the system conversion efficiency of 2.68% can be measured.