Research On High-performance Rectification Technology For Wireless Energy Transmissio

Wireless power transmission is a technology that uses electromagnetic waves as a carrier to transmit energy without using power lines.With the rapid development of the Internet of Things,the application range of wireless power transmission technology is gradually expanding.This technology has great application prospects in the fields of aerospace,weapon reconnaissance systems,industrial robots,electric vehicles,Internet of Things sensor nodes,smart homes,biomedical implants,and so on.The rectenna consists of a receiving antenna and a rectifier circuit,which is responsible for receiving RF signals in space and converting them into DC signals.It plays an important role in wireless power transmission systems.This paper first proposes a universal method for expanding the bandwidth of rectifier circuits,and uses this method to design two multi branch broadband rectifier circuits.Subsequently,a broadband antenna was designed to serve as a receiving antenna,which was combined with the previous two rectifier circuits to form a two-branch rectenna and a four-branch rectenna.Finally,an optimization method for wireless power transmission efficiency under non-uniform incident power density distribution is proposed,and the feasibility of this optimization method is demonstrated by establishing a complete wireless power transmission system.The main work of this article is as follows:This paper proposes a simple multi branch structure for improving the bandwidth of rectifier circuits.A single-branch rectifier circuit is designed,which is connected in parallel with a rectifier circuit that has the same structure and size as it,forming a two-branch rectifier circuit.Compared to the single-branch structure,the relative bandwidth of the two-branch rectifier circuit is increased to 81.6%.Using the same method,a four-branch rectifier circuit is designed,and the relative bandwidth is increased to 84.7% compared to the single-branch rectifier circuit.The practicability of this scheme for increasing the bandwidth of rectifier circuits is proved.This paper designs a broadband antenna and uses it as a receiving antenna in wireless power transmission systems.The designed antenna has a bandwidth of 11.68 GHz and a range of 0.85 GHz to 12.53 GHz,meeting the requirements of broadband receiving antennas.Two types of broadband rectennas were obtained by combining the broadband antenna with twobranch rectifier circuit and four-branch rectifier circuit,respectively.The performance of the two types of rectennas was measured.This paper proposes a method for optimizing wireless power transmission efficiency under non-uniform incident power density distribution.Using mathematical fitting,the characteristics of the rectifier circuit can be fully characterized and modeled as a mathematical function.The rectifier efficiency can be derived as a mathematical expression with constraints,and then the maximum efficiency can be determined using mathematical methods.Based on the maximum condition,it is easy to design a rectifier circuit array.Using this optimization method,a wireless power transmission system was fabricated.Designed and processed a 16 × 16 transmission antenna array,a receiving antenna composed of 4×4 large units and a rectifier circuit.The feasibility of this optimization scheme is verified through experiments.