Study On High Efficient Rectenna

Wireless energy transmission technology is one of the research hotspots in the field of energy transmission.There are three main ways to realize wireless energy transmission: induction type,resonance type,and rectenna type.Among them,rectenna has the advantages of long transmission distance,good directivity,low cost,and small size,and is one of the key technologies for microwave energy transmission and environmental energy harvesting.The efficiency of the rectenna is mainly affected by the efficiency of receiving antenna in rectenna and rectifier circuit.Based on microstrip rectifying antenna,this article mainly to improve the efficiency respectively in receiving antenna and rectifier circuit part.The main work of this paper is as follows:1.Left-handed materials with electromagnetic focusing characteristics are designed,showing "double negative" characteristics at the corresponding frequency.The LHM has a small insertion loss after being added to the microwave energy transmission system and can realize the electromagnetic focusing function within a certain range,thus improving the effective receiving area of the antenna.The microstrip antenna with left-handed material has obvious gain enhancement compared with the one without it so it can improve the transmission efficiency of the whole microwave energy transmission system.2.The rectifier circuit is designed based on the Ga N diode with the transverse structure on the semi-insulated 6H-Si C substrate,which improves the rectifier efficiency and the effective working power range of the rectifier circuit.3.On the basis of the above,the rectifier antenna system including microstrip antenna,filter,matching network,and rectifier circuit is designed with a lumped element and discrete element respectively.The actual test shows that its performance meets the requirements.4.To expand scope of the antenna working frequency,this paper designed the dual-band rectifying system,the system by using dual-frequency filters and double-frequency matching circuit,achieved in both 2.45 GHz and 3.5 GHz effective function to work,compared with the traditional rectifier circuit system,it has the advantages of working frequency width and able to work dual-band.Simulation and actual test results show that: with the electromagnetic lens,receiving power of the antenna is increased by 514%;with the rectifier circuit of Ga N diode,the power range above 50% rectifier efficiency is improved by 75% compared with ordinary Schottky diode;the rectifier antenna with dual-frequency rectifier system has a maximum rectifier efficiency of 57.25% at 2.45 Ghz and 51.92% at 3.5Ghz.