一种壁厚渐变蜂窝宽带透波结构

A Novel Wideband Transparent Structure with Tapered Honeycomb

采用介电常数渐变结构是一种有效实现宽带透波的方法。为实现介电常数随厚度变化,本文提出了一种壁厚渐变六边形蜂窝结构。根据蜂窝等效介电常数的近似计算公式和介质介电常数变化分布,计算出该渐变结构的几何参数。基于渐变线宽带匹配理论,对空气和高介电常数介质进行宽带匹配设计,从而得到介质介电常数随厚度渐变的分布规律。为验证该设计方法的有效性,采用CST商用仿真软件,对该结构的周期单元透波性能进行仿真。仿真结果表明该结构在垂直入射和大入射角情况下,具有良好的宽带透波特性。通过改变芯层材料厚度可以进一步调整宽带透波特性的起始频率。

Inhomogeneous planar layer is one of good structure for wideband transparent application. In this paper,a hexagonal honeycomb structure with tapered wall thickness is proposed so as to realize dielectric constant variation across the dielectric thickness. The geometry parameters of the structure are calculated according to the equivalent permittivity formulation of dielectric honeycomb and the dielectric constant distribution. Based on the tapered transmission line matching technique,air is matched with high dielectric constant material. Then the dielectric constant distribution across the thickness is derived. The effective of the design method is evaluated by CST commercial software. The electromagnetic transmission property of the unit cell is simulated. The simulation results indicate the structure have good wide band transparent property at normal incidence and large incident angle. The frequency start point of wide band structure can be changed by changing the thickness of the core layer material.