Research On Nonlinear Devices In Microwave Wireless Power Transmission System

The early energy transmission systems used cables as carriers,which suffered less interference.but there were a series of problems such as the need to build a complex system,the cost is high,and the long-term system maintenance.The emergence of microwave wireless power transmission technology(WPT)has just compensated for this shortcoming,and its performance in various aspects has been continuously optimized and improved with the development of technology.With the diversification of application scenarios,in addition to the requirements for transmission efficiency,the requirements for frequency and power capacity are also gradually changing.This paper is dedicated to the research of non-linear devices in this system,mainly including the improvement of power capacity and the widening of frequency bands.The research content is as follows:1.Select the device model that matches the design direction,through the analysis of the existing power amplifier components.The relationship between the static operating point and the harmonic signal is analyzed,and the appropriate static operating point is selected in combination with the harmonic suppression index.Load-pull is used to design wideband input-output matching to achieve design indicators such as gain and output power.And analyze the wideband matching method of small signal amplifier.Through schematic diagram simulation analysis,layout simulation is optimized,combining board parameters and the power that each node in the circuit can withstand,and using two power amplifiers in parallel to combine the output to complete the layout design.In the course of the experiment,a wideband power amplifier design with excellent linearity and saturated output power of 100 W was finally completed under the octave operating bandwidth.2.Compared with more Schottky diode rectifier circuits,the related research based on GaN HEMT rectifier circuits is less.Driven by the background of demand for highpower rectification,by analyzing the I-V characteristics of GaN HEMT under different operating conditions,it can be proved that it can be used as a rectifier device,and the power capacity of the rectifier circuit can be improved.In terms of widening the operating frequency,after principle analysis and formula derivation,the two frequency points in the L band under the same matching structure can achieve rectification efficiency of 65% and 76%,respectively.The final experimental results show that under the working frequencies of 1.15 GHz and 1.7GHz and the input power of 10 W,the rectification efficiency reaches 50% and 65%,respectively,and the design of the dual-frequency high-power rectifier circuit is completed.A design method for building a broadband high-power microwave wireless energy transmission system proposed by this paper.Starting from the design theory of power amplifiers and rectifier circuits,the design indicators were completed by combining simulation models,simulation tools,and experimental experience.