用于无线能量传输系统的微带天线设计

Design of Microstrip Antenna Applied to Wireless Power Transmission System

本文提出一种用于组成无线能量传输(Wireless Power Transmission,WPT)系统的微带天线结构,并采用基于有限元法的电磁仿真软件(HFSS)对微带天线进行3D建模。在二端口网络分析法的基础上,建立磁耦合共振无线能量传输等效电路模型,求解出系统发生频率分叉现象产生的条件以及最大效率时的频率表达式。基于以上方法,研究本文设计的微带天线传输特性,包括:系统的最优传输效率与耦合距离的关系,工作频率与耦合距离的关系,得出在能量传输距离在50cm左右时,天线的谐振频率为12.5MHz,效率可达63%。微带天线具有很大的结构优势,如与集成电路兼容,成本低,体积相对较小,且工艺相当成熟,易大规模批量生产等优势。因此该设计的平面微带天线可用于无线能量传输系统。

A configuration of microstrip antenna is proposed for design of wireless power transmission(WPT) system.Via electromagnetic simulation software HFSS which is based on Finite Element Method(FEM),we establish 3D modeling microstrip antenna.The equivalent circuit model of wireless power transmission system via magnetic resonance coupling is analyzed contactless based on the two-port network analysis method.The condition of the resonant frequency splitting phenomenon is produced,a wireless power transmission system is deduced,and the frequency expression of maximum efficiency is derived.Based on the method above,by researching characteristics of transmission of this system including :the relationship between optimal efficiency of transmission system and the coupling distance and the relationship between the working frequency and the coupling distance. we concluded that when the energy transmission distance is in 50 cm, microstrip antenna the resonant frequency of which is 12.5MHz still has a high efficiency(63%).The microstrip antenna has advantages on its great structure,such as compatible with integrated circuit,lower cost,relatively small volume, technical maturity,and easy to mass production and so on. So the design of planar microstrip antenna can be used for wireless power transmission system.