磁谐振无线传能的高性能体内接收线圈设计

Design of high-performance receiver coil for transcutaneously magnetically coupled resonance wireless power transfer

针对植入式装置的经皮无线能量传输中,体内接收小线圈品质因数低、自谐振频率高且难以与体外线圈匹配共振的问题,提出采用多子线圈串接构建空心体内能量接收线圈兼作植入电路的封装,并对子线圈中外径26 mm的印刷平面螺旋线圈(P-PSC)进行优化设计.在选定基材、基板厚度和线厚的基础上,采用部分元等效电路法仿真计算P-PSC的自谐振频率和品质因数,分析内半径、匝数及线宽线距比的影响,优选得到低剖面、高性能PPSC的设计参数.测得双层P-PSC的自谐振频率和品质因数分别为10.37 MHz和82.3,结果表明:本研究的单、双层P-PSC性能综合评价指标均高于同类线圈,空心能量接收线圈尺寸为Φ26.00 mm×4.55 mm,自谐振频率低至6.78 MHz,品质因数可达67.1,在满足安全限制的条件下,距离发射线圈4 cm的接收功率为269 mW,能量传输效率(PTE)为24.2%.

Aiming at the problem of low quality factor,high self-resonant frequency of the small receiver coils inside the body,and the difficulty in matching the resonance with the external coils in transcutaneously wireless power transfer for implanted devices,the use of multiple sub-coils connected in series to construct the receiver coil that also served as the case of the implanted circuit was proposed,and the printed planar spiral coil(P-PSC)with an outer diameter of 26 mm in the sub-coils was optimized for design.On the basis of determining the substrate material,substrate thickness and track thickness,the partial element equivalent circuit(PEEC)method was used to simulate and calculate the self resonant frequency and quality factor of P-PSC.The influence of inner radius,number of turns,and the ratio of trace width to spacing was analyzed,and the design parameters of low-profile and high-performance P-PSC were optimized.The proposed double-layer P-PSC prototype was fabricated with the measured self-resonant frequency of 10.37 MHz and quality factor of 82.3.Results show that the proposed single and double-layer P-PSCs are superior to those documented comparable coils.A hollow receiver prototype with 26.00 mm in outer diameter and 4.55 mm in height is constructed with the self-resonant frequency of 6.78 MHz and the quality factor of 67.1.Under the condition of meeting safety restrictions,the received power at a distance of 4 cm from the transmitter is 269 mW with the power transfer efficiency(PTE)of 24.2%.