Research On Wireless Energy Transmission System Based On Electromagnetic Signal

With the rapid development of new communication technologies such as 5G,the era of everything being interconnected has arrived.Mobile phones,tablets,and smart wearable devices are increasingly being used in people’s daily lives.On the one hand,these electronic devices,including sensors widely used in the Internet of Things,will inevitably face power supply issues.Although battery technology is quite mature today,using battery power still faces a series of problems such as high prices,high maintenance costs,and environmental unfriendliness.On the other hand,advances in integrated circuit technology have further reduced the power consumption of electronic devices,making it possible to supply devices with wireless electromagnetic signals.However,due to the complex wireless energy transfer environment,how to effectively collect and receive wireless RF energy will become a design challenge,and the design of rectifying antennas also faces many challenges such as bandwidth,miniaturization,and transmission efficiency.Firstly,a 2.4GHz single-frequency circularly polarized rectifying antenna was designed.The circular polarization of the antenna provides stronger environmental adaptability and better penetration,resulting in improved energy conversion efficiency.Simulation results using HFSS software show that the circularly polarized antenna can cover an impedance bandwidth of 2.04～3.80 GHz,with a 3d B axial ratio bandwidth of220MHz(2.28～2.50GHz)and a maximum gain of 3.7d Bi.The rectifying circuit was optimized using ADS software simulation,and the results show that the rectification efficiency is over 60% between 2.26～2.78GHz(520MHz).Finally,the antenna and rectifying circuit were physically fabricated and tested,with good agreement between the simulation and measurement results.Secondly,a circularly polarized rectifying antenna that operates in both the2.4&5.8GHz dual-frequency bands was designed.Simulation results show that the antenna has an impedance bandwidth of 310MHz(2.21～2.52GHz)and 3.73GHz(5.33～9.06GHz)in the 2.4GHz and 5.8GHz frequency bands,respectively,with a 3d B axial ratio bandwidth of 260MHz(2.32～2.58GHz)and 420MHz(5.66～6.08GHz).For dual-frequency applications,the rectifying circuit was improved and optimized for the front-end matching circuit and output low-pass filter,based on the single-frequency application.Simulation and measurement results show that the circuit has an overall rectification efficiency of over 60% in both the 2.4&5.8GHz frequency bands.