侧馈偏置卡塞格伦天线的面赋形研究

为改善星载天线的宽角扫描特性,采用射线追踪的方法,通过优化的思想对侧馈偏置卡塞格伦(SFOC)天线的主反射面进行了面赋形设计．为增加反射面表达式的灵活性,设计时首先根据反射面的初始数据,以双三次B样条函数逼近其形状,然后以各馈源相位中心到与其对应的扫描口径面的路径等长为优化目标,通过Powell方法对样条函数的插值数据点进行调节,最终确定了反射面的形状．分析结果表明,面赋形工作有效降低了SFOC天线一维扫描和二维扫描过程中由相位误差带来的增益损失,改善了该天线系统的宽角扫描特性．     

一种新型微带天线及其宽角扫描特性研究

该文主要描述了一种适合宽角扫描的相控阵天线单元设计思路,研究了其组阵实现宽角扫描的特性。为尽量减少大角度扫描过程中由于天线单元波束宽度有限带来的阵列增益下降,采用折叠地板的方式展宽天线单元半功率波束宽度;同时,为了降低互耦引起的天线单元方向图畸变,在宽波束设计基础上探索了降低天线互耦的方法,使得真实阵列方向图尽可能地满足方向图乘积定理,从而实现宽角、高增益扫描的目的。经一维线阵的仿真和测试,设计了一种能扫描到±70°且增益变化不大的宽角扫描阵列。设计的天线还能作为一种典型的天线单元,应用于5G等民用消费电子场景。     

表面误差对侧馈偏置卡塞格伦天线辐射场的影响

以侧馈偏置卡塞格伦双反射面天线为对象,通过数值计算方法分析了该天线的平均功率方向图,研究了反射面随机表面误差对天线辐射特性的影响．分析过程中首先将反射面上某点的随机误差量定义为该点在标准反射面法线方向上的偏移量,并认为反射面上每一个小区域内的偏移量相同,然后在随机表面误差带来的口径相位误差服从均值为零的正态分布的条件下,推导了天线平均功率方向图的计算公式,并利用该公式模拟计算了相关的数据和曲线．文中结果可为反射面制造精度的确定提供参考．     

一种超宽带高增益对踵Vivaldi天线

本文设计了一种带宽3.3～40 GHz的新型超宽带高增益对踵Vivaldi天线,该天线介质板两侧采用相同的辐射结构,由一个微带线和两条指数型槽线构成.在天线辐射方向添加一块梯形结构介质板,将天线正反两面的表面电流限制在天线辐射方向,既可以矫正E面方向图的增益峰值偏移角度,也可以提升天线辐射强度.实测结果显示,3.3～4...     

新型超宽带宽波束圆极化天线

简单介绍了平板圆片单极天线.提出了一种新型的组合单极天线形式,这种天线将四个圆片单极子垂直交叉放置,不仅依然能够在很宽的频带上满足反射损耗的要求,而且该天线具有较宽的波束和波束范围内有较好的圆极化性能等特点.对这种新型天线进行了分析,给出了天线的设计方法,研究了其超宽带性能,详尽讨论了天线的反射损耗、辐射方向图、轴比图,以及增益和群延时特性.分析结果验证了其在实现宽波束圆极化的同时具有良好的超宽带性能.这种新型小型化天线在无线通信、卫星通信和移动通信中具有良好的应用前景.     

新型加载印刷天线构成的宽带双极化馈源

提出了一种新型宽带折叠加载印刷偶极子天线,并在其基础上进行改进,研究用于前馈抛物反射面天线的双线极化或双圆极化馈源。利用基于有限元法的电磁仿真方法对该馈源进行了分析,并运用物理光学方法计算了用该馈源构成的反射面天线的特性。仿真及测试结果表明,该馈源频带宽（fmax/fmin=2）、重量轻、容易实现双线或双圆极化。具有馈源方向图边缘电平容易控制、相位中心恒定等优点。是一种简单实用的馈源。     

机载通信天线辐射特性分析

采用一致性几何绕射理论分析了某型航空飞行器机体对其上安装的通讯线天线辐射方向图的影响,给出了航空飞行器散射模型建立的原则和方法,对安装在飞机表面的通信线天线阴影区散射场计算公式进行了详细的分析推导,设计了机载通信线天线辐射方向图计算软件,可快速准确计算机载天线辐射方向图．以通信常用单极子天线为例,计算了机体表面不同安装位置线天线受载机影响辐射方向图,该结果对机载天线安装位置优化有指导意义．     

一种平面微带阵列天线的仿真与分析

为了获得可应用于工程的具备理想特性的天线,在Ku波段设计了一种平面结构的微带阵列天线.在设计微带天线的辐射贴片结构基础上完成了馈电网络和八元阵列天线的设计,通过CST仿真软件构建阵列天线模型,并优化天线的尺寸参数,得到天线的S参数、驻波特性和增益方向图等特性.仿真结果表明,该微带阵列天线具有高增益和低副瓣特性,且方向性...     

宽角扫描相控阵天线测量方法

提出了一种基于坐标变换技术的宽角扫描相控阵天线测量的新方法,用于解决常规平面近场测量方法难以对宽角扫描相控阵天线进行精确测量的问题.在对用于宽角扫描相控阵天线测量的坐标变换技术进行理论分析的基础上,采用计算机模拟对该测试方法进行了数值仿真,制作天线实物进行了试验验证.数值仿真结果和试验结果均表明,该方法用于宽角扫描相控阵天线的测试具有较高的准确性.     

一种基于电磁(光子)晶体基底的新型贴片天线的研究

给出了一种基于电磁(光子)晶体基底的新型贴片天线.用时域有限差分法(FDTD)研究了该新型天线的表面波以及阻抗、辐射方向图、带宽和增益等;并将它们与普通贴片天线进行了比较.结果表明,光子晶体结构对表面波的抑制非常明显,从而改善了天线的性能,包括增加了天线的带宽,提高了向前辐射的增益,削弱了沿基底方向(90°侧面方向)的辐射等.     

Efficient PO-MOM Method for Analysis of the Radiation Characteristics of a Large Antenna-Radome System

An efficient hybrid method based on the method of moments(MOM)and physical optics(PO)for the analysis of radiation characteristics of an electrically large antenna-radome system is presented.Specifically,MOM is first applied to the antenna to find the current on its surface,and then the equivalent PO currents produced by the antenna radiation are assumed on the radome wall.When the coupling of the PO currents and antenna current is considered,the coupling matrix is divided into a series of partial matrices,in order to deduce the memory requirement and accelerate the evaluation process.Numerical results indicate that the proposed hybrid PO-MOM method is accurate and efficient.     

Design of the beam scanning microstrip reflectarray antenna

For the aim of designing a wide-angle low sidelobe beam scanning microstrip reflectarray antenna, a new design method based on a new aperture phase distribution of three focuses is proposed. This method introduces a new phase distribution determined by three focuses for wide-angle beam scanning firstly. Then the aperture phase distribution is further optimized by the hybrid particle swarm algorithm to reduce the side lobe level of the pattern. Based on the optimization, the antenna realizes beam scanning by use of a moving feed. In order to verify the effectiveness of the design method, a Ku-band circular polarized beam scanning reflectarray antenna is designed and fabricated. The measured results agree well with the simulated ones, with the side lobe level being below -18dB within the scan range of 52°and the band reaching 108％(the overlapping 3dB axial-ratio (AR) and 1dB gain bandwidth).     

Radiation Characteristics of the Reflector Antenna with Random Perforated Holes

The radiation characteristics of a doubly curved shaped reflector antenna with random holes is analyzed by physical optics (PO) method, and the probability model of the random holes and its numerical realization method are presented. The radiation patterns show that in the azimuth plane the peak sidelobe level becomes much higher as the reflector surface with random holes. The simulation results can provide a theoretical guidance for the radar attackers.     

Design of a miniature broadband internal antenna for PD detection in GIS

According to the analysis of the relationship between the impedance and bandwidth of the dipole antenna, a novel elliptical plane internal antenna feeding by a coaxial line is presented. It consists of an elliptical monopole and a rectangular grounding piece and has the virtues of broad band, high gain and small size. The antenna can be used for ultrahigh frequency (UHF) partial discharge (PD) detection in the gas-insulated switchgear (GIS). The size is achieved by using the simulation software Ansoft HFSS and the optimum size of total antenna is 90mm×45mm. A prototype is constructed and studied, and then measured. The antenna covers a large band from 781MHz to 2.00GHz, with the VSWR less than 2.5 and a max gain of 3.55dB. Simulated and tested results are in good agreement and the radiation pattern and gain characteristics are given.     

圆柱共形全向微带缝隙天线阵的设计

该文设计了一种圆柱体表面共形的全向微带缝隙天线阵.该天线采用低剖面缝隙天线作为阵列单元,利于实现共形;采用H形缝隙对天线单元进行小型化设计,以实现较小间距的组阵,从而获得较好的方向图不圆度.对提出的天线进行仿真设计及优化,获得了5.35％的相对带宽,仿真增益达到4.2dBi,H面不圆度≤1.5dB.