低副瓣稀布阵天线优化设计-电子与通信工程专业毕业论文.docx

摘要
实现低峰值副瓣电平的优化设计。此外,由于各个子阵的结构相同,子阵内部采用的均匀分布结构,还简化了阵列系统的馈电网络。
。首先采用13阶多项式表示稀布阵列阵元位置分布函数,修正传统稀布阵列优化模型,把阵元位置的优化布阵问题转换成n 阶多项式系数的优化问题;然后以峰值副瓣电平为适应度函数,利用粒子群优化算法寻找适应度值最小的多项式系数组合,实际仿真中采用4-6阶多项式表示阵元位置分布函数,完成了阵元数目为32的稀布直线阵列优化设计,最终优化得到的峰值副瓣电平约等于直接采用粒子群优化算法优化阵元位置的峰值副瓣电平,该方法减少了优化变量的维度,有效的减少了计算量,提高了计算效率。
。在子阵划分方法的基础上,利用粒子群
算法优化稀布阵列的子阵的位置分布或者子阵的位置分布和激励加权,以降低方向图峰值副瓣电平。同直接用粒子群优化算法优化阵元的位置分布相比,得到的辐射方向图峰值副瓣电平更低。由于只是优化子阵位置分布,减少了优化维度, 提高了计算效率。同时,划分子阵还简化了馈电网络的设计。
关键词:稀布阵列;辐射方向图;峰值副瓣电平;子阵划分:多项式;粒子群优
化算法
II
万方数据
From the far field area to be observed,based on principle of superposition and interference of ic waves,the radiation pattern of the antenna array is the
superposition effect of all the elements in the Can make the array antenna
gain hi曲gain and high resolution beam in the far field by designing the parameters of the array antenna:the number of elements,the aperture of the array and the element of the Can also set the weighting of array element excitation phase to gain beam scanning in an angular low side—lobe and high gain or a specific
radiation pattern could be achieved by using uniform array antenna and adjusting the
excitation amplitude of array ,in some engineering applications of army antennas,high gain is not required,but a higher resolution is other words,the larger array aperture is more order to satisfy the requirements
of beam scanning and no generating the grating lobes,amount of elements and
overspending is needed by using the uniform array that element spacing normally is a half ,we need to set different excitation for a large number of elements because the uniform array achieves a low side-lobe level or expected specific radiation pattern by weighting excitation amplitude and feeding system is needed to ,we usually utilize unequally army to achieve this type of of sparse array is