Electromagnetic Performance Analysis of a Novel Monolithic Radome for Airborne Applications

A monolithic half-wave hybrid variable thickness radome (hy-VTR) is proposed here for airborne applications. The 3-D ray-tracing (in conjunction with aperture integration method), which is adapted here to evaluate the radome performance parameters, facilitates efficient analysis of antenna-radome interactions. The optimized power reflection hy-VTR design is established to be superior to the conventional constant thickness radome (CTR) designs in terms of the EM performance.      

弹载螺旋天线及天线罩电气性能分析

弹载天线的天线罩是天线的重要组成部分,由于尺寸的限制,天线罩距离天线辐射体非常近,甚至紧贴辐射体,因此天线罩对天线的辐射具有严重的影响。给出了一种适合于弹载的小直径螺旋天线的设计参数,利用矩量法分析了天线罩对天线电气性能的影响,并进行了实际设计和测试,验证了分析结果,指出在这种天线的设计时要充分考虑天线罩的电气性能。     

一种基于介质填充的天线罩电厚度反射测试波导探头

电厚度是雷达天线罩重要的电性能参数,在天线罩制造过程中经常需要采用反射测量方法实现工艺控制,但测试能力严重受限于测试探头与被测天线罩的失配反射影响.在分析失配原理的基础上,提出了反射测试波导探头内部介质填充方法,通过结构不连续性和介质不连续性的分离,实现了失配反射信号的内部自然抵消.给出了明确的介质填充形状和结构参数设...     

天线罩在地面天线系统中的应用

介绍了不同口径天线中使用的截球型天线罩的外形结构、电气性能指标,这种天线罩由玻璃钢单元件搭接拼装而成,采用随机分块,拼缝经过结构和电调谐.由于采用了新技术、新工艺,各项性能指标均超过欧洲进口天线罩,具有抗风能力强、外形美观、安装方便、电性能优秀、防漏雨和抗盐雾侵蚀性好的特点,可在各种环境条件下使用,应用前景广泛.该天线罩的设计方法对同类天线罩的设计有借鉴作用.     

APPROXIMATE COMPLEX RAY ANALYSIS OF TWO-DIMENSIONAL RADOME

Electromagnetic transmission and scattering characteristics of radome may conve-niently be analyzed by complex ray paraxial approximation and collective ray methods.As anexample,a 2-D cylindrical single-layered dielectric radome is analyzed and calculated in this in-vestigation,including radome transmission coefficient,radar angular track performance and radarcross section of radomes,as well as the effect of ray parameters and antenna-radome parameterson computation accuracy.It is shown that this method can be used to simplify optimizations formany kinds of radomes.     

雷达薄壁天线罩的密封及防护

探讨了雷达薄壁天线罩的密封及防护问题,介绍了天线罩材料的老化性能和常用密封胶的性能及特点,针对平面阵列中薄壁天线罩的特点进行了密封设计及密封胶的优选,确定了单组份聚氨酯密封胶胶层厚度与固化时间的关系,并通过专用底处理剂及含氟涂料的使用,提高了密封胶的粘接强度及天线罩的防老化性能.     

S/Ka双频段馈源新型喇叭罩设计

论述了一般喇叭罩的设计原则和思路,提出了采用B夹层结构的聚四氟乙烯S/Ka双频段馈源喇叭罩的设计思想,及喇叭罩的具体设计方法.实验证明,该喇叭罩性能优良,已成功应用到某大型S/Ka双频段工程中.     

C波段机载干扰机天线罩的分析与设计

运用微波等效网络法对机载干扰机天线罩进行了计算机辅助设计,计算的天线罩透波率、加罩天线辐射特性与实测结果相吻合。研制的C波段机载干扰机天线罩经高低温、振动、静压试验,性能良好,其透波率达85％以上,达到了设计指标要求。     

Optimization of two-dimensional radome boresight error performanceusing simulated annealing technique

A systematic approach to radome design is presented. The problem is formulated as a global optimization procedure such that the radome performance is optimized by properly adjusting the thickness of the radome layer over the entire radome surface. In this approach the thickness profile is parameterized via B-splines representation. Simulated annealing technique is applied to finding the best thickness profile so that the maximum boresight error is reduced to as small as possible over the entire range of the antenna look angle. A two-dimensional design example is given. The best possible thickness profile is found and the boresight error is reduced considerably compared to that due to a uniform layer. The method is general and can be applied without difficulty to other realistic three-dimensional radomes of arbitrary shapes     

机载宽频带雷达罩双向变厚度设计方法

新一代战机的火控雷达向着宽频带和相控阵方向发展。针对宽频带相控阵机头雷达罩的高性能要求,提出了“高传输、低反射、等插入相位延迟”综合设计准则。分析了宽频带夹层罩壁结构的电性能特性,针对其相位特性差的情况给出了一种新的双向变厚度设计方法。通过雷达罩轴向变厚度设计以适配不同的入射角获得高传输/低反射性能,通过环向变厚度设计以适配不同的极化角获得接近的插入相位延迟,实现了优良的宽频带传输性能和方向图特性,在雷达罩产品研制中得到应用并发挥了重要作用。     

Numerical optimization of a cylindrical reflector-in-radome antennasystem

Accurate numerical optimization based on rigorous solution of the integral equation using the method of analytical regularization is performed for a cylindrical reflector antenna in a dielectric radome. It is shown that the multiple scattering in this system is more significant for the optimum radome design than any nonplane-wave effects or the curvature of the radome. We claim that, although the common half-wavelength design is a good approximation to avoid negative effects of the radome (such as the loss of the antenna directivity), one can, by carefully playing with the radome thickness, its radius, reflector location, and the position of the feed, improve the reflector-in-radome antenna performance (e.g., increase the directivity) with respect to the same reflector in free-space     

基于某型吊舱天线罩的电性能分析与设计

天线罩设计是一项具有挑战性的工作.结合某型吊舱天线罩设计任务,本文采用等效平板原理分析了天线罩电透过性能,并在此基础上对天线罩进行了电设计,运用几何光学-射线跟踪方法分析了天线罩的引入对天线辐射特性的影响,给出了方向图和透波率的测试曲线,很好的达到了设计指标要求.目前该型天线罩已投入使用,性能良好.     

隐身雷达罩技术研究进展综述

雷达罩作为飞行器的结构/透波功能一体化部件,其隐身要求具有很大的技术挑战性。雷达罩的隐身设计与实现必须保证雷达天线工作频带内的透波功能,实现雷达罩透波/隐身的一体化功能。隐身雷达罩是航空武器装备实现隐身性能的关键部件,对于降低飞行器头向RCS值、提高飞行器的综合性能和作战效能具有举足轻重的作用。文中分析了雷达罩的散射特点,综述了各种雷达罩隐身措施的具体途径及优缺点,重点阐述了频率选择表面技术、电磁带隙、等离子体隐身技术及超材料等技术的特点、实现隐身的作用机理及在隐身雷达罩中的应用,指出了未来发展的趋势。     

雷达罩瞄准误差测量不确定度评定方法研究

雷达罩电性能测试系统是一种复杂的计量器具,需要对其检测结果的不确定度进行评定,以前在这方面几乎没有开展工作。以雷达罩电子定标法为例,对影响瞄准误差测试结果的主要因素进行了分析,确定了不确定度分量。采用A 类或B 类评定方法,对每个分量的标准不确定度进行了分析计算。研究了不确定度分量之间的相关性,并对合成标准不确定度和扩展不确定度进行了计算。该方法也可用于雷达罩传输效率、方向图畸变和功率反射等电性能参数测量不确定度的评定。     

基于近场场图的带罩天线近副瓣畸变分析

采用FEKO软件仿真带罩天线远场方向图和近场场图, 采用近场场图分析远场方向图近副瓣畸变的原因.仿真过程中采用等效源技术, 兼顾仿真精度和仿真效率.带罩天线方向图近副瓣畸变主要是由天线罩尖部区造成的, 近场场图表明三种效应导致近副瓣抬升:其一, 电磁波经过天线罩尖部发生明显的衍射, 波阵面分叉; 其二, 金属雨蚀头被激励出表面电流, 进而产生二次辐射; 其三, 部分电磁波能量经反射后透过天线罩尖部区域, 反射-透射电磁波能量叠加在副瓣方向上.针对上述效应, 对天线罩改进设计, 改进后可明显抑制带罩天线近副瓣的抬升.近场场图分析方法揭示了天线罩局部细节和远场方向图之间的联系, 对天线罩电性能优化设计有很好的指导作用.     

频选雷达罩电性能的基本问题及解决方法

频率选择表面(FSS)雷达罩技术是新一代战机实现隐身的重要途径。基于目前国内外FSS研究和实践的结果,从FSS的基本要素出发,对FSS雷达罩电性能设计涉及的谐振频率、带宽、栅瓣等基本问题进行了分析、研究、梳理和归结,针对雷达罩入射角和入射波极化变化的情况,对FSS如何增加频带宽度、实现谐振频率与带宽的稳定性、避免栅瓣对RCS的影响等提出了应对办法,指出FSS单元选择、设计小尺寸单元并将它们紧凑排列以及正确地进行介质加载是获取优良电性能的关键。     

A streamlined metallic radome

The results of research and development, fabrication, and measured transmission performance for a specific streamlined metallic radome are contained in this paper. The measured results presented demonstrate that high-quality radome transmission performance can be attained with a streamlined metallic radome. The conical metallic radome presented is 6 ft 4 in long and has a base diameter of 25.5 in. The specially designed resonant slotted surface of the metallic radome consists of 90 percent metal and, for frequencies within its operating band, the radome permits transmission with any signal polarization over a wide range of scan angles. At its 8.90 GHz resonant frequency the metallic radome introduces less than 0.5 dB signal loss and less than 2 mrad boresight error. This radome has been purposely designed for operation over a narrow frequency band. Over a 200 MHz band, measured insertion loss and boresight error values of 1 dB and 6 mrad, respectively, are attained.     

曲面频选天线罩电性能设计研究

针对现如今频率选择表面(FSS)普遍基于平板进行理论研究的现状,提出了一种基于HFSS-Matlab创建曲面频率选择表面的方法。设计了平板频选单元及A夹层平板天线罩,并进行了仿真分析;采用该方法将准周期排列的曲面频选单元附于A 夹层正切卵形介质天线罩表面。为了验证曲面频选的性能,选用宽波束的平面螺旋天线作为激励,对曲面频选天线罩天线系统进行了联合仿真,并分析了加载曲面频选结构对天线罩电性能的影响。结果表明,所设计的曲面频选结构与平板FSS结构电磁性能基本保持一致,实现了曲面FSS 频率选择的功能,在传输段内不仅能够满足天线罩电性能设计指标要求,而且能有效降低天线带内强镜面反射(RCS),对曲面频选天线罩的实际工程应用具有指导意义。     

基于滤波器电路设计多层带通频率选择表面

针对传统多层频率选择表面（frequency selective surface，FSS）的设计存在计算量大、耗时长等问题，提出了一种基于滤波器理论和FSS等效电路设计多层FSS的方法.该方法先由滤波器理论综合得到多层FSS的等效电路，再利用FSS等效电路的反演方法将其电路模型转换成多层FSS的结构参数.物理过程简单直观，可以实现任意层数的高阶FSS的快速精确设计.为了验证该方法的准确性，完成了一种K波段带通型三阶FSS天线罩设计以及实物样件加工、测试.测试结果表明该天线罩的传输曲线与滤波器理论设计结果基本一致，且对天线辐射方向图的影响较小，为多层FSS的精确设计提供了一种精确理论设计方法.     

On the Characteristics of Radome Enclosed Archimedean Spiral Antennas

The effects of the superspheroidal radomes on the characteristics of Archimedean spiral antennas are investigated in detail, which may provide some useful insights in the design of the radome-antenna system in practical engineering. All interactions between the radome and antennas are rigorously included in the coupled surface integral equation (CSIE) model, which leads to more accurate results than those of the existing methods based on the high-frequency algorithm or the decoupled radome-antenna analysis procedure especially when the antennas are placed in the close proximity of the radome. Numerical results show that the performance of the spiral antenna is significantly changed due to the presence of the radome.