用于微波热疗的近场聚焦微带阵列天线设计

The Nead-field-focused Microstrip Antenna Array Used In Microwave Hyperthermia

目的:设计并制作了一种工作在2450 MHZ的8×8近场聚焦平面微带阵列天线,用于肿瘤的体外热疗。方法:实验通过控制微带线的长度来改变天线口径上每个阵元的相位,使阵元的电场在距离平板中心高度为40 cm处实现同相叠加,从而实现近场聚焦。用有限元数值方法对天线阵列在真空的近场分布以及人体肌肉模型中的近场分布和SAR分布做了模拟计算。并对天线在真空中的近场分布进行了实物测试。结果:仿真结果显示焦斑在真空中为椭球形,其长轴为230 mm,短轴为65 mm;测试结果与仿真结果相吻合,长轴为240 mm,短轴为72 mm。结论:64元微带阵列天线可以很好地在预定的焦点位置实现聚焦,并能透射进入相对介电常数为47,电导率为0.4 s/m的仿人体介质中,该天线阵列满足微波体外热疗的要求。

Objective：Designing and manufacturing a planar microstrip array antenna which is used in microwave hyperthermia in vitro. Methods：By controlling the length of the microstrip line to change the phase of each array element of antenna aperture so that the EM of each array element can realize the in-phase stacking at the Planar array center in the height of 40cm.At this time,the EM will be focused in the specified location. Simulated the antenna array＇ s distribution of near-field in vacuum as well as the near-field＇ s distribution and SAR distribution in the muscles model of the human body by finite element method, the near -field distribution has been tested in vacuum. Results：Simulated result show that the focal spot is ellipse in vacuum,the long axis of the focal spot is 230 mm,the short is 65 mm;The test results are in good agreement with the simulation results,the long axis is 240 mm and the short is 72 mm. Conclusions： From the result , The 64 element microstrip antenna array can realize the focusing on focus position ,and energy can transmit into the imitation of human medium with the relative dielectric constant is 47 and electrical conductivity is 0.4 s/m. From the result, the NFF array antenna meets the requirements of microwave hyperthermia in vitro.