基于拓扑与形状优化的小型化金属天线设计方法

天线小型化设计需要基于先进的设计方法,基于拓扑优化的设计往往存在灰度单元,因此设计结果无法直接应用,需要进一步规整设计。而对于电磁金属结构,粗糙的规整方法会引起结构性能的很大变化以致偏离最优结果。提出一种拓扑优化和形状优化相结合的方法,用于金属天线结构的小型化设计。该方法通过拓扑优化获得金属天线结构的概念构型,进而利用形状优化对概念构型进行边界规整和精细化设计。形状优化方法采用多控制点贝塞尔曲线描述拓扑概念构型,通过贝塞尔曲线控制点的移动实现天线构型的调控。给出了贝塞尔曲线控制点的设置原则,基于拓扑优化得到场量分布结果,利用较少的贝塞尔曲线控制点实现天线拓扑构型结构特征的有效调控。该方法可以获得无灰度单元残留的拓扑结果,同时可有效避免密度阈值规整方法中天线性能改变的问题,并且获得的拓扑构型边界光滑。数值算例表明拓扑优化和形状优化相结合方法的有效性。此外,该方法可拓展到其他类型电磁器件的优化设计中。

Topology and shape optimization based method for miniaturization design of metallic antenna

Advanced design methods are required for the design of miniaturized antenna.Grey elements often exist in topology optimization based designs,which results in difficulties in practical applications,so further regularization of the design is needed.As for an electromagnetic metallic structure,the design performance usually changes when the density threshold based method is applied,which leads to deviation of the performance of the optimal result.In this paper,a topology and shape optimization based method is proposed for the miniaturization design of a metallic antenna.The concept configuration of the antenna is obtained through topology optimization firstly.Then a shape optimization scheme is carried out for the boundary regularization.The boundary of the antenna is described with Bezier curves.By adjusting the location of points of the Bezier curves,the shape of the antenna can be flexibly optimized.The principle for setting the control points is provided in this paper,with which detailed features of the topology configuration can be effectively regulated with fewer points.With the proposed method,the grey elements are removed and the deteriorated performance issue caused by density threshold method is avoided.Moreover,the boundary of the antenna is much smoother to ensure the antenna can be easily fabricated.Numerical examples show that the proposed method is effective for the miniaturized design of metallic antennas.This method can also be extended to the optimization of other metallic devices.