温福高铁宁德滨海特大桥覆盖创新解决方案

随着我国高铁的迅猛发展,为满足高铁乘客的手机等电子终端语音与上网体验,如何有效解决高铁覆盖问题显得愈发重要。本文针对温福高铁宁德滨海特大桥长度长、间距大、施工复杂等难题,创新应用高增益宽波瓣天线、小区合并、传输环网、大功率直流远供、海域钢玻璃防腐槽道等新技术,有效解决高铁特大桥长期存在LTE综合覆盖率差、用户感知差难题。     

基于栅瓣等波动阵列设计方法

宽带侦察DBF的突出问题是高频段信号会出现严重的栅瓣。文中针对宽带DBF中栅瓣问题,提出了一种基于栅瓣等波动阵列方法,即阵元间距的选择随着宽带信号的频率变化而变化,其核心是对阵元间距的选则。并通过仿真验证了该方法的有效性。     

一种超低旁瓣天线设计的研究

通过对雷达信号空间谱的分析和变换获得空域的加权系数 ,利用得到的加权系数对阵列天线各单元信号进行加权后再叠加 ,可设计出一种超低副瓣的雷达阵列天线 ,并可通过实时改变其加权系数以获得不同特性的天线     

Evolutionary optimization for pattern synthesis and reduction of mutual coupling of linear antenna arrays

Optimal design of antenna arrays to minimize the mutual coupling effects in the geometrical arrangements of the linear antenna array (LAA) and circular antenna array (CAA) is dealt with in this work. Two different cases are considered to reduce the effect of LAA and CAA: Case‐1 in which the current excitations of the antenna array are considered to get the optimal radiation pattern of two geometry called LAA and CAA and Case‐2 in which inter‐element spacing and current excitations are both optimized for LAA geometry. A cost function that involves the mutual coupling factor as an optimization factor is developed to reduce the side lobe level (SLL), which takes mutual coupling effects into consideration. Excitation values and inter‐elemental spacing are optimized using particle swarm optimization (PSO). In LAA, for 8‐, 12‐, 16‐element arrays, SLLs are reduced by ?15.52, ?16.71, and ?17.78 dB in Case‐1. For the same sets of element arrays, SLLs were reduced by ?17.35, ?19.71, and ?20.26 dB in Case‐2. In CAA, the current excitations of the antenna array are optimized. For 8‐, 12‐, and 16‐ element arrays, SLLs are reduced to ?7.405, ?10.52, and ?9.43 dB, respectively. The arrays coded with the help of MATLAB based computation and the results obtained by MATLAB are validated by using CST.     

一种Ⅹ-KU波段TSA天线设计

渐变开槽天线（Tapered Slot Antenna）具有宽频带、结构灵巧、易于电路集成和组成相控阵列等优点,但是通过分析和设计常规的指数型TSA天线,发现其存在后瓣和旁瓣较大、增益较低的缺点.通过改进天线整体结构和局部开槽的方法,优化了常规TSA天线表面和渐变槽线边缘的电流分布,并利用HFSS设计了一付工作于X波段、KU波段改进型TSA天线,与设计的常规天线TSA相比,天线主辐射方向3dB波瓣宽度增大,最大增益提高,后瓣和副瓣得到了一定的抑制.     

PCFC雷达信号测量性能分析与优化

为了提高雷达信号的测量性能,推导了脉内相位编码(Phase-coded,PC)脉间频率编码(Frequency-coded,FC)雷达信号的模糊函数,分析了该体制信号模糊表面峰值分布与FC之间的关系,定义了旁瓣矩阵均值概率,并以此为优化目标,提出了通过遗传算法优选FC,改善该体制信号模糊特性的方法。仿真结果证实,该方法能有效压低模糊表面副峰或使得副峰远离主峰,从而提高该体制雷达信号的测量特性。     

Design of non-uniform circular antenna arrays for side lobe reduction using the method of genetic algorithms

A design problem of non-uniform circular antenna arrays for maximal side lobe level reduction with the constraint of a fixed beam width is dealt with. This problem is modeled as a simple optimization problem. The method of genetic algorithms is used to determine an optimum a set of weights and antenna element separations that provide a radiation pattern with maximal side lobe level reduction with the constraint of a fixed beam width. The effectiveness of genetic algorithms for the design of non-uniform circular arrays is shown by means of experimental results. Experimental results reveal that design of non-uniform circular antenna arrays using the method of genetic algorithms provides a considerable side lobe level reduction with respect to the uniform case.     

Position-only planar hexagonal array antenna pattern nulling with simultaneous side lobe reduction at multiple azimuth planes

This article presents a study on the placement of multiple nulls as well as minimization of side lobe level in the radiation pattern using a planar hexagonal antenna array structure in two different vertical planes. The desired null depth is achieved to suppress the interference signal by the position-only control of the uniformly excited isotropic antennas in the array structure. The immediate solution to the mentioned computational problem is reached by various meta-heuristic optimization algorithms such as teaching learning-based optimization (TLBO), symbiotic organism search (SOS), and moth fly optimization (MFO) within a considerably reduced processing time with a control over the design constrains. Various examples for diversified scenarios are demonstrated to place multiple deep nulls in the radiation pattern without compromising the pattern constraints and all other radiation pattern characteristics. This experiment sought to illustrate and quantify the unique benefits and limitations of proposed technique using three considered meta-heuristic optimization algorithm.     

利用太阳辐射测量阵地上的雷达天线

太阳辐射出大量噪声电磁波,人们可以利用太阳辐射的噪声电磁波测量阵地上雷达的天线波瓣和增益。VHF雷达的波瓣受到地面反射的强烈影响,这些影响也可通过本文提出的方法测出。     

目标航迹的快速起始

为解决近程搜索跟踪系统对空中目标的快速锁定,分析了目标回波的特点,通过对目标回波进行的预处理,包括点迹的稳健凝集、副瓣和辅助质心的消除,提高了数据质量,减少了后续处理的工作量,为航迹快速起始奠定了基础。给出了目标航迹快速起始的2种方法:两点起始和三点起始航迹。建立的模型和采用的方法在多个工程项目中进行了应用,达到了快速起始的目的。