FDTD-PWS法用于分析毫米波透镜天线焦面场

提出一种新的节省计算空间的FDTD-PWS混合算法,并应用于透镜天线的焦面场分析.首先采用FDTD(Finite-Difference Time-Domain)求解得到聚焦透镜天线的口面场的幅度和相位分布,再通过PWS(Plane Wave Spectrum)外推至焦平面,求解得出焦面场分布.根据天线场分布的对称性,将PEC(Perfect Electric Conductor)和PMC(Perfect Magnetic Conductor)边界应用于FDTD的仿真过程,使仿真模型缩减为原模型的1/4,进一步节省了计算空间.应用于毫米波聚焦透镜天线的焦面场仿真分析,并对其焦面场进行平面近场扫描测试,将仿真结果进行探头补偿后与实验数据作比较,证明该方法是精确和高效的.

Hybrid FDTD-PWS method for focal field analysis of lens antenna at millimeter-wave band

A novel hybrid finite-difference time-domain (FDTD) method and plane wave spectrum(PWS) method was presented for analysis focal field distribution of lens antenna.Firstly,the amplitude and phase distribution in the aperture was simulated by the FDTD method.Moreover,the antenna model was reduced to 1/4 by the pertect electric conductor(PEC) and perfect magnetic conductor(PMC) boundary conditions.And secondly PWS method was applied to calculate the focal field distribution.In order to demonstrate the accuracy and efficiency of this new method,a lens antenna at millimeter-wave band was designed and simulated as an example.Then this lens antenna was measured by the planar-near-fields(PNF) method.Finally,the influence of the measurement probe was characterized also by the FDTD method and taken into account by the calibration.And it is found that the results of focal spot size obtained by the FDTD-PWS method are in good agreement with the experiment data by the probe compensation.