共查询到18条相似文献,搜索用时 156 毫秒
1.
2.
圆柱面上的轴向偶极子阵的低副瓣方向图优化综合 总被引:1,自引:1,他引:0
本文利用新的非线性最优化方法讨论圆柱面上的轴向偶极子阵的低副瓣方向图优化综合问题,利用阵列的单元可实现增益方向图,我们把阵列综合问题表述为一个约束非线性规划问题,采用新直接法求解该问题即可得出一组使阵列的总方向图满足副瓣指标要求,同时具有尽可能高的方向性系数的激励系数,如果阵列的总方向图不能达到副瓣指标,则可得出一组使阵列方向图在可达到的副瓣方向图综合设计的模拟计算结果。 相似文献
3.
一种新的低副瓣曲线阵数值综合方法 总被引:3,自引:2,他引:3
本文提出了一种新的低副瓣曲线阵数值综合方法。把曲线阵综合问题表述为约束非线性最优化问题,利用新直接方法求解它,即可求出使阵列的总方向图满足特定的副瓣电平指标,且具有尽可能高的方向性系数的激励和空间分布,文中主要给出了自由空间曲线阵综合的数学模型和计算结果,并给出了直线阵时新综合方法与Taylor分布的比较结果。新综合方法也适用于共形曲线阵综合问题。 相似文献
4.
该文针对毫米波共形相控阵天线阵列稀布引起的栅瓣问题,提出了一种最优极化(交叉极化电平最小)条件下的阵列稀布优化准则。该方法首先建立毫米波共形相控阵雷达导引头极化辐射方向图的数学模型,通过对圆极化和线极化两种极化方式下交叉极化电平的比较,选取最优极化方式,选定阵列稀布优化的两组基本参数,然后利用改进的粒子群进化(MPSO)算法优化两组参数条件下的阵元分布,对比阵元分布优化后的天线方向图确定阵列稀布优化的基本准则,来有效抑制由于阵列单元稀布而引发的栅瓣效应。仿真试验证明该准则的合理性。 相似文献
5.
阵列置零的同时,阵列的旁瓣电平升高、主瓣增益降低甚至阵列指向都会发生改变,导致阵列性能降低。针对阵列置零时阵列性能降低问题,提出一种约束优化模型。在约束优化模型中不仅设置了零陷深度约束和近旁瓣电平约束,还设置了阵列期望方向增益约束及阵列指向约束。在满足约束条件下,使得阵列旁瓣电平最低。并且针对标准约束差分进化算法收敛慢,采用自适应约束差分进化(e-SADE)算法,该算法采用多种变异方式相结合、自适应地调节交叉概率和缩放因子。运用自适应约束差分进化分别通过调节阵元相位和阵列功率一定时的阵元权值求解这个约束优化问题,仿真结果表明提出的方法实现了需求的目标方向图,利用自适应约束差分进化算法优化实现阵列置零是有效可行的。 相似文献
6.
7.
8.
9.
针对时间调制稀疏阵列天线方向调制信号综合问题提出了一种分步迭代凸优化算法.通过对阵元开启时长和开启时刻的分析,将方向图的上下界约束转化成凸问题.通过对中心频带和边带方向图的分步优化,使期望辐射方向上只有中心频带辐射,边带信号形成零陷.稀疏线阵的仿真结果验证了所提算法的稳定性和高效性,达到了方向调制信号综合的目的. 相似文献
10.
11.
A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual coupling and mounted platform effects is used to calculate the far-field patterns.A coordinate transform is applied to create polarization quantities,and a general process for the element polarized pattern transformation is performed.Corresponding numerical example is given and the desired sidelobe level and low cross-polarization are optimized.The numerical results indicate the proposed method is valid. 相似文献
12.
Antenna array pattern synthesis via convex optimization 总被引:9,自引:0,他引:9
We show that a variety of antenna array pattern synthesis problems can be expressed as convex optimization problems, which can be (numerically) solved with great efficiency by recently developed interior-point methods. The synthesis problems involve arrays with arbitrary geometry and element directivity, constraints on far- and near-field patterns over narrow or broad frequency bandwidth, and some important robustness constraints. We show several numerical simulations for the particular problem of constraining the beampattern level of a simple array for adaptive and broadband arrays 相似文献
14.
基于基片集成波导结构提出了一种新型双层电磁超材料单元,并验证了其左手特性。将超材料单元应用于漏波天线的设计,所设计的天线由15个双层电磁超材料单元组成。将设计好的天线进行加工测试,测试与仿真结果吻合较好,表明漏波天线的工作频带为7.20~12.70GHz,在工作频带内可实现从后向-78°到前向+80°的连续主波束扫描,天线在工作频带内的测试增益均大于10dBi,峰值增益为15.2dBi,3dB增益带宽达到50.2%。此外,该漏波天线具有很低的交叉极化电平,交叉极化始终比主极化低至少30dB。相比于新近文献报道的同类型超材料漏波天线,所设计的天线具有更加优越的电气性能。 相似文献
15.
16.
The design of a dual-polarized microstrip series-fed linear traveling-wave array is described in this paper. The array is composed of two identical subarrays formed by cascading an equal number of four-port aperture-coupled cross-patch elements and terminated on a two-port radiating matched load. By properly exciting the array, dual linear or circular polarization can be accomplished and by virtue of the symmetric arrangement of the antenna cross-polarization is annihilated. A straightforward design strategy is proposed for the synthesis of a desired current distribution along the array antenna. Some proof-of-concept linear arrays are developed and the corresponding numerical results, obtained through a full-wave approach based on the method of moments (MoM), are provided. As an independent validation, supplementary analyses by the finite integration technique (FIT) are also reported. Very close agreement is found between prescribed and synthesized array performance, which qualifies the proposed design approach as an accurate and effective tool for the synthesis of series-fed aperture-coupled patch arrays. 相似文献
17.
Scattering response of an electrically small bianisotropic particle suspended in free space is presented. Formulation of this problem is based on the assumption that the electrical small bianisotropic particle can be modelled as both an equivalent electric and a magnetic dipole moments. It is found that cross-polarization and/or co-polarization phenomena may occur for certain constitutive relations, separatively. 相似文献
18.
A pair of novel 180deg broadband microstrip baluns are used to feed a dual-polarized patch antenna. The 180deg broadband balun delivers equal amplitude power division and consistent 180deg (plusmn5deg) phase shifting over a wide bandwidth (>50%). We demonstrate that for a dual-polarized quadruple L-probe square patch antenna, the use of the proposed 180deg broadband balun pair, in place of a conventional 180deg narrowband balun pair, provides improved input port isolation and reduced H-plane cross-polarization levels over a wider frequency range, while maintaining low E-plane cross-polarization levels and stable E- and H-plane co-polarization patterns throughout the impedance passband 相似文献