柔性共形阵发射方向图性能分析

Analysis of Transmitting Pattern Performance for Flexible Conformal Array

柔性共形阵(Flexible Conformal Arrays,FCA)是一种天线载体形状随时间可变的特殊共形阵列天线。为了分析FCA发射方向图随外形控制参数的性能变化,本文建立了一种通用的机翼共形FCA模型,可采用两种控制参数模拟调整机翼的外形变化,并在此基础上建立了方向图和阵列互耦模型。根据控制参数的组合变化,分析了四种典型场景下天线性能的变化情况,包括间接参数和直接参数(阵元位置是否直接受参数控制)的变化引起不同程度的主瓣展宽和旁瓣电平升高;阵元间互耦效应受参数变化的影响而使阵列最大辐射能力下降;以及控制参数对阵列扫描特性的影响。同时,利用全波仿真软件HFSS建模得到了阻抗参数,以此分析了FCA的互耦特性。理论分析与仿真结果均表明建模的FCA变形模型能够灵活控制其发射方向图特性。

Flexible Conformal Arrays(FCA)is a kind of special conformal array antenna whose conformal surfaces change with time.In order to analyze the performance of FCA emission patterns with shape control parameters,a general conformal FCA model of aerofoils is established in this paper.Two control parameters can be used to simulate and adjust the shape change of wings.On this basis,the pattern and array mutual coupling model are established.According to the combination changes of control parameters,the antenna performance varys in four typical scenarios are analyzed,including the changes of indirect parameters and direct parameters(whether the array element position is directly controlled by the parameters)causing different degrees of main lobe broadening and sidelobe level increasing.The mutual coupling effect between array elements decreases the maximum radiation capability of the array due to the change of parameters.and the influence of control parameters on array scanning characteristics.At the same time,the impedance parameters are obtained by full-wave simulation software HFSS to analyze the mutual coupling characteristics of FCA.The coupling information is used to calculate the mutual coupling matrix of the array and to evaluate the mutual coupling leakage of the array,so as to obtain more realistic simulation results.Four typical scenarios show that due to the variation of control parameters,the performance of FCA changes.The change of control parameters leads to the increase of mutual coupling between array elements,which makes it necessary to consider this factor in array pattern synthesis.The relevant conclusions and analysis methods can be extended to any general FCA analysis.Both theoretical analysis and simulation results show that the modeled FCA deformation model can flexibly control its emission pattern characteristics.