EMCoS Studio在车载天线布局与线缆设备上的仿真应用

目前,越来越多的工程应用涉及到在电大尺寸平台上装载不同天线并连接复杂线缆。对于这样的复杂系统,文中主要研究了这些天线、线缆间的耦合问题。利用EMCoS Studio软件的电磁工具、线缆工具以及混合工具,很好地解决了车载平台系统中天线、线缆问题以及它们之间的耦合问题,为系统的电磁兼容提供了有效的解决方案。文中对不同频段的6副天线与3类线缆的不同耦合状况进行了仿真,结果表明,天线间、线缆间以及天线与线缆间在工作频段均不存在干扰。     

一种星载相控阵天线的热设计研究

随着技术的发展,相控阵天线在星载平台得到越来越多的应用,其电磁指标要求也越来越高。天线的高电磁指标对结构的刚度、轻量化和高效散热设计参数提出了严苛的要求。星载相控阵天线一般安装在航天器的外表面,深冷空间及太阳辐射等空间环境对其温度影响巨大。文中对一种星载相控阵天线的热设计进行了研究,根据热设计输入对相控阵天线的散热方案、热管选型和热控措施进行了分析,通过仿真、试验验证了热设计的合理性。     

纸基RFID标签天线喷射打印化学反应沉积成形

针对目前射频识别(RFID)标签天线制备成本高、工艺复杂等问题,提出微滴按需喷射3D打印与化学沉积技术相结合制备半波偶极子天线的方法。利用构建的气动式双喷头微滴喷射系统,采用试验研究的方法,对系统按需喷射条件下产生硝酸银与抗坏血酸微滴的一致性以及基板运行速度对成线均匀性的影响进行研究,并对成形导线的电阻率进行测试;在此基础上设计、仿真和制备了半波偶极子天线,对其性能参数进行了测试。结果表明:系统产生的微滴均匀性较好;基板速度小于或等于0.5mm/s时,硝酸银成线边缘光滑度较好;成形导线的电导率为1.57×10~(-5)Ω·m;打印成形的半波偶极子天线谐振频率、谐振点回波损耗S_(11)参数等与仿真结果具有较好的一致性。为RFID标签天线提供了一种低成本制备方法。     

电性能仿真平台及其在大型面天线机械结构设计中应用

大型面天线在工程中有着广泛应用,其机械设计与电气设计是分开进行的。天线结构设计人员由于不了解电磁理论,只能依靠经验设计天线机械结构,来保证天线满足电气设计人员提出的精度指标。结果是生产周期很长,成本浪费严重。因此,有必要建立天线电性能仿真平台。在设计天线虚拟电子样机之后,通过该平台来计算天线电性能,判断天线结构是否满足要求。工程中应用此平台,将使结构设计人员提高天线设计与制造效率,减少次品率,降低天线设计与制造的成本。     

一种片式T/R组件的热电协同设计方法研究

针对高密度集成有源相控阵雷达系统中的T/R组件存在显著热-电磁性能耦合的问题。提出一种片式T/R组件的多学科建模及仿真设计方法,通过提取T/R组件的结构和电磁单学科特征进行混合建模,建立用于热-电磁协同分析的多学科数模; 对T/R组件多学科数模进行电磁-电路、热-电磁协同分析,获得收发通道的S参数以及实际激励下T/R组件的温度分布; 更换芯片在真实温度下的S参数,通过迭代仿真分析直至T/R组件的热、电磁性能全部满足设计要求。该方法具备模型快速修改、不同物理场之间数据匹配传递等优点,可以实现T/R组件的快速、准确全性能设计。     

基于热电致冷的雷达高频箱环控技术研究

高温高湿盐雾等恶劣环境会对雷达高频箱内电子元器件的寿命和可靠性产生很大影响,其中湿度影响尤为重要,因此必须对高频箱内的相对湿度进行控制。针对高频箱的结构特点,提出了一种新型雷达高频箱除湿方式—热电致冷除湿。与雷达高频箱常用的空调除湿方式相比,热电致冷除湿具有结构简单、体积小、可靠性高等优点。以某大型相控阵雷达高频箱为对象进行的仿真结果表明,热电致冷除湿方式完全可满足高频箱除湿的要求。通过比较不同工况下的仿真结果,发现合理的风速可以获得较好的除湿效果。研究成果可为未来解决高频箱湿度控制这一关键技术问题提供有益的参考。     

一种激光全息RFID双重防伪电子标签设计

介绍了一种激光全息射频识别(RFID)双重防伪电子标签的设计方法,并通过理论分析和电磁仿真,研究了激光全息膜对无源RFID天线射频性能的影响规律。在此基础上设计了一款共面倒F天线,并应用于无源RFID标签,且制作了样品。测试结果表明,使用该天线的激光全息RFID标签能达到较好的读取效果,并且受激光全息膜的影响较小。     

星载薄膜反射阵天线机电耦合模型及其应用

薄膜反射阵天线面密度低、收纳比高、电设计自由度高,在实现星载天线“高增益”、“轻巧化”的要求上有巨大的优势。但目前还没有在轨使用的大口径薄膜反射阵天线,主要是因为薄膜在空间热环境、光场、电磁波辐射、粒子辐照、重力梯度等多物理场中容易产生大变形与振动,严重影响天线的电性能。为验证大口径薄膜反射阵天线在空间大规模运用的可行性,建立了薄膜反射阵天线的机电耦合模型,研究了反射阵单元误差和馈源误差对天线电性能的影响,分析了薄膜反射阵天线形变与振动对增益和副瓣电平的影响,为薄膜反射阵天线的在轨误差分析提供参考。     

舰船通信系统电磁干扰探讨

随着电子技术、通信技术的飞速发展,对舰船通信能力的要求也不断提高,舰船通信系统多频段、多业务和多电台同时通信成为对舰船通信系统的基本要求.电磁干扰是影响舰船通信系统通信质量的主要原因.要提高通信质量,就要对通信系统的电磁干扰进行系统性分析.在通信系统中,天线作为实现通信电磁发射、接收的载体,是通信系统设计时的主要关注点之一.文中分析了舰船通信系统多天线之间的相互作用以及相互干扰产生的可能原因,就改善通信系统电磁干扰提出了建议.     

Variable fidelity metamodel-based analytical target cascading method for green design

Along with the increasing attention on the environment and resources, green design and green manufacturing has become a tendency nowadays. In order to mitigate the computational burden when solving green design problem of the complex engineering system, a variable fidelity metamodel-based analytical target cascading framework (VFATC) is developed to explore the application of variable fidelity (VF) metamodels in analytical target cascading (ATC). In this VFATC framework, a VF approximation modeling method is developed, which employs both computationally efficient simplified (low fidelity, LF) and expensively detailed (high fidelity, HF) information. To efficiently integrate the LF and HF information, kriging is enhanced to scale LF model (LFM) to HF model (HFM). Then, the scaled LFM is used as an approximation model to replace the analysis models in VFATC. The effectiveness of VFATC framework is applied into a lightweight design problem of cantilever beams and a ship design problem with the objective of oil consumption reduction. Overall results show the VFATC methods introduced in this paper provide an effective way of improving computational efficiency of multidisciplinary green design optimization problems based on complex HF simulation models.     

New equipment for microwave electric field visualization

We present the operation and design of newly developed, fully automatic equipment for the visualization of microwave electric fields. This equipment enables the observation of microwave field patterns around different objects including metamaterial prototypes and to study the field patterns of various microwave antennas and other objects that have been developed and that interact with a surrounding microwave electromagnetic field. Moreover, the developed prototypes whose interaction with an incident electromagnetic wave is crucial for practical applications can be investigated using size scaling, and hence our equipment can be used for the testing of antennas and other devices that interact with electromagnetic radiation, not only at microwave frequencies, but also at radio frequencies. The performance of our innovative equipment was demonstrated through the investigation of the metamaterial cloak. The frequency behavior of the metamaterial cloak revealed frequency bands with maximum cloaking efficiencies.     

一种熔融沉积3D打印的高性能超材料吸波结构

高性能超材料吸波结构是近年学术界和工程界研究的热点,它通过单元结构的周期阵列排布形成吸波超材料结构,实现超材料的吸波层与自由空间的阻抗匹配,大幅提高对电磁波的吸收率,在隐形技术、通信天线及微波成像等军事和民用领域具有广阔的应用前景。基于超材料阻抗匹配原理,提出了熔融沉积3D打印技术制备超材料吸波结构的方法,实现了一种由聚乳酸（Polylactic acid,PLA）单元空腔和具有优异电磁特性的蒸馏水复合组成的超材料结构的精确设计与制造,获得了在8.2~30.0 GHz电磁波频带内具有90%以上吸波率的高性能超材料吸波结构。研究表明该超材料结构还具有良好的极化无关和宽角度吸波特性。所设计制造的超材料吸波结构具有性能强、厚度薄、质量小等诸多优异的特性,为推动高性能吸波结构的深入研究提供了一种新的思路。     

Two-step Structural Design of Mesh Antennas for High Beam Pointing Accuracy

A well-designed reflector surface with high beam pointing accuracy in electromagnetic performance is of practical significance to the space application of cable mesh reflector antennas. As for space requirements, circular polarizations are widely used in spaceborne antennas, which usually lead to a beam shift for offset reflectors and influence the beam pointing accuracy. A two-step structural design procedure is proposed to overcome the beam squint phenomenon for high beam pointing accuracy design of circularly polarized offset cable mesh reflectors. A simple structural optimal design and an integrated structural electromagnetic optimization are combined to alleviate the beam squint effect of circular polarizations. It is implemented by cable pretension design and adjustment to shape the offset cable mesh surface. Besides, in order to increase the efficiency of integrated optimization, an update Broyden-Fletcher-Goldfarb-Shanno (BFGS) Hessian matrix is employed in the optimization iteration with sequential quadratic programming. A circularly polarized offset cable mesh reflector is utilized to show the feasibility and effectiveness of the proposed procedure. A high beam pointing accuracy in order of 0.0001º of electromagnetic performance is achieved.     

直线式波浪能发电装置设计

针对旋转式波浪能发电装置由于存在中间环节转换而导致发电效率降低的问题,围绕直线式波浪能发电装置设计中的关键技术,通过三维建模技术和Ansoft/Maxwell仿真软件,开展了铁芯槽口大小优化、磁铁充磁方式选择、磁铁间隙优化以及铁芯纵向端部效应改善和弥补方法等研究,提出了一种直线式波浪发电装置,对优化后的直线发电机模型进行了电磁瞬态仿真分析,进而得出该发电机的电磁力矩曲线、磁链曲线、以及所产生的感应电动势曲线图,为直线式波浪能发电装置设计提供了理论依据。研究结果表明,该发电机的励磁源选择了钕铁硼永磁材料,具有功率大、性能指标较优越、结构紧凑简洁、噪音低、效率高等显著优势,端部铁芯齿宽度增大可以解决和弥补纵向边端效应的问题。     

Application of genetic algorithm and Taguchi method in dynamic robust parameter design for unknown problems

Taguchi method was known in many industries as an off-line quality control methodology to improve the performance of products or processes at low cost. Although it was effective at improving quality, the statisticians pointed to inefficiencies in the method for highly nonlinear problems and complexity of the product design, the results were often less than satisfactory. Therefore, recently mathematical model and computer simulation are the other alternatives for robust design. However, Taguchi method and computer simulation have their own advantages and disadvantages. So, this idea motivates the approach of combining both advantages together to promote the more effectiveness of robust design. This paper proposes the approach to apply computer-aided engineering (CAE) with genetic algorithm (GA) and Taguchi method in dynamic robust parameter design. Firstly, we use computer simulation, CAE, to obtain the data instead of conducting whole real experiment. Next, a statistical approach, linear regression is used to model the unknown functions, and then GA, heuristics search approach, is employed to find the appropriate setting of controllable factors on the basis of the quality loss function. The effect of noise factors which is the important philosophy of robust design is also considered by utilizing the outer orthogonal array. The objective is to minimize the average quality loss instead of maximizing SN ratio. In addition, to enhance the capability of the proposed approach, the two-step method is applied to screen out the dispersion factors significantly affecting the quality variation and the adjustment factors significantly affecting the sensitivity of the Taguchi’s dynamic system for the case of changing products or processes’ requirements in the future. This proposed is applied to the example “Foam design of automobile’s dashboard”.     

柱形爆炸容器动力学响应的有限元模拟与实验检验

应用ANSYS／LS—DYNA非线性有限元程序,对爆炸容器爆心截面部位的环向应变进行了数值模拟。为检验模拟结果,进行了相应当量的化爆实验。分析应变波形发现,两种方法所得峰值应变相近,且峰值到达时间基本一致。由于实际容器的结构响应有多种振型参与,使得试验波形比模拟波形复杂。应用有限元模拟法可研究爆炸容器动态响应的基本特征,在设计和研究爆炸容器时应用该方法成本低、效率高。     

Recognition of Borehole Radar Cable-Related Effects Using Variable Offset Sounding

Conductive cables can influence borehole radar measurements and introduce artifacts into data and therefore must be considered during data analysis and interpretation. This study presents examples of some cable-related effects in data acquired with a radar system that relies on conductive cables for signal transmission. Data show that measurements can be affected when energy radiated from the transmitter antenna induces currents on conductive cables, which can function as an electromagnetic waveguide, allowing fields to propagate along cables and be detected by the receiver antenna. Additionally, periodic artifacts can result when currents traveling on cables reflect at system impedance mismatches.Variable offset soundings (VOS) are not typically conducted during borehole radar studies, but can be useful for recognizing cable-related effects on recorded data and studying propagation characteristics in a borehole. In addition to single-hole VOS measurements, VOS measurements made on the ground surface using E-Plane and H-Plane configurations are shown to have the potential for providing additional insight in regards to coupling mechanisms between borehole antennas and cables.     

考虑太阳照射的地基面天线机电耦合分析

下一代深空探测的地基面天线的面精度要求达到亚毫米级,必须考虑太阳照射导致的温度的影响。针对这一问题,以"嫦娥工程"的40 m通信面天线为研究对象,根据天线的地理位置和时间日期,计算天线受到的热流密度;考虑对流、传导和辐射三种传热方式计算天线的温度分布,并用某7.3 m卡式天线设计温度试验,结果表明温度分析是有效的;将温度作为载荷计算天线的结构变形;根据天线远区的电场公式计算电性能,并提取增益损失、副瓣电平和指向误差等主要电性能指标。仿真结果表明,温度对电性能的影响不但体现在结构变形的均方根值上,更与变形的分布形式密切相关。分析的方法和结论可用于指导下一代面天线结构设计,也可供同类型面天线设计时参考。     

电磁轴承力学特性的有限元分析

利用有限元法对轴向电磁轴承的磁场分布进行了数值模拟分析，并通过对某一实际电磁轴承的轴向轴承磁场分布及电磁力的分析计算，得出了轴向电磁轴承的承载力工作范围和静态刚度曲线，所得结果可作为轴向电磁轴承实际设计的准则。     

一种超高频RFID工业洗衣标签设计

针对工业中的洗衣标签提出了一款超高频的设计方案,运用仿真软件建立模型,分析标签性能,并制作实物进行测试,结果显示标签满足设计要求。考虑到工业洗衣可能给标签带来的弯折,洗衣标签在制作上采用了可靠性较高的工艺和封装,并分析和测试了标签的弯折性能。测试结果表明,洗衣标签能够很好地运用到实际环境中。