Material Equivalent Test Based on Dimensional Analysis for Fragment Penetrating Antenna Target

Phased array radar is the main sensor in a battlefield.Phased array antenna is the main execution unit of the phased array radar,and it greatly affects the reliability of the phased array radar. As a result,the fragment damaged antenna test is important.As the materials of phased array antenna are not easy to get,the fragment damaged antenna test is difficult to carry out. Then we present a study on this problem and introduce the principles of dimensional analysis to solve it. Firstly, the fragments damage antenna target dimensionless model is constructed. Secondly,the finite element analysis software ANSYS / LS-DYNA are used to carry out a large number of different materials simulation test for dimensional analysis. Finally,based on dimensional test analysis,the materials equivalent empirical model between different antennas target is presented in the same damage. The results of this study provide a feasible and valuable solution for different materials' target damaged test.

Two-Dimensional Topology Optimization of a Horn Antenna

A two-dimensional horn antenna is used as a model for topology optimization. In order to employ the topology optimization, each point in the domain is controlled by a function which is allowed to take values between 0 and 1. Each point’s distinct value then gives it an effective permittivity, either close to that of polyimide or that of air, two materials considered in this study. With these settings, the optimization problem becomes finding the optimal distribution of materials in a given domain, and is solved under constraints of reflection and material usage by the Method of Moving Asymptotes. The final configuration consists of two concentric arcs of air while polyimide takes up the rest of the domain, a result relatively unsensitive to the choice of constraints and initial values. Compared to the unoptimized antenna, a slimmer main lobe is observed and the gain boosts.

Notched Triangular Microstrip Antenna for Dual-Frequency Operation

A novel equilateral triangular patch with a rectangular notch etched to one radiating edge on organic magnetic substrate is proposed for dual frequency operation. Both operations of these dual frequencies arise from the perturbation of TM 10 and TM 11 mode by simply cutting a rectangular notch at the patch bottom. Simulations and experiments have shown the validity of this design. Using an organic magnetic material as the substrate, the antenna exhibits a broader bandwidth of 5.5% and 4.7% at dual-frequencies 1.56 GHz and 2.45 GHz, respectively, as well as a reduced size compared to the dual-frequency patch antennas on non-magnetic material.

Effect of Absorption of Patch Antenna Signals on Increasing the Head Temperature

Every new generation of antennas is characterized by increased accuracy and faster transmission speeds.However,patch antennas have been known to damage human health.This type of antenna sends out electromagnetic waves that increase the temperature of the human head and prevent nerve strands from functioning properly.This paper examines the effect of the communication between the patch antenna and the brain on the head’s temperature by developing a hypothetical multi-input model that achieves more accurate results.These inputs are an individual’s blood and tissue,and the emission power of the antenna.These forces depend on the permeability and conductivity characteristics of the metal from which the antenna is fabricated.The proposed model is the first one that links the material the antenna is manufactured from and the head’s temperature.The results show that there are only a small number of materials that should be used as antenna covers.These materials are in the form of thin films.By using these thin films at different temperatures,the risk to the head can be reduced.This paper finds that the best results were obtained when the patch antenna was made of one of the following materials operating at a specific temperature:traditional materials at 305°K;casting cast steel at around 295°K;bismuth telluride(Bi2Te3)at 290°K;or barium sodium niobate at 310°K.

The Effect of Laminate Angles in Composite Substrates on the Performance of Rectangular Microstrip Antenna

The performance of a microstrip antenna has been known sensitive to substrate’s dielectric properties, which is dependent on the angle of laminate layers inside a composite laminated substrate. Modal analysis in spectral domain is applied to investigate the resonant frequency and radiation pattern of rectangular microstrip antenna on composite substrates. It is shown that the substrate’s dielectric properties are dependent upon the laminate angles, i.e., upon the orientation of the antenna relative to the substrate’s fiber direction. For the same operating frequency, the antenna size on composite substrates is larger than that on isotropic substrates, and the far field pattern is also more directional.

Investigation and Comparison of 2.4 GHz Wearable Antennas on Three Textile Substrates and Its Performance Characteristics

In this paper, two different methods were used for investigating the RF characteristics of three types of textile materials. Goch, Jeans and Leather substrates were studied. A microstrip ring resonator method and DAK (Dielectric Assessment Kit) method were used. Bluetooth antennas were designed and fabricated using these substrates. The results were compared for the two methods. The bending effect of these antennas on its impedance characteristics due to human body movements was also studied. Finally, all antennas were simulated by CST simulator version 2016, fabricated using folded cupper and measured by Agilent 8719ES VNA. The measured results agree well with the simulated results.

Optimization of Ni_(0.95-x)Zn_(x)Co_(0.05)Fe_(1.90)Mn_(0.02)O_(4) ceramics with promising magneto-dielectric properties for VHF antenna miniaturization

Magnetic,dielectric and DC conductive properties of Ni_(0.95-x)Zn_(x)Co_(0.05)Fe_(1.90)Mn_(0.02)O_(4)(with x=0-0.20 at an interval of 0.05)ferrite ceramics were studied,in order to develop magneto-dielectric materials with almost equal values of relative permeability and permittivity,for the miniaturization of HF(3-30 MHz)and VHF(30-90MHz and 100-300 MHz)antennas.The ferrite ceramics were prepared by using the conventional two-step sintering process.The real part of relative permeability is increased almost linearly with increasing concentration of Zn,while that of relative permittivity keeps nearly unchanged.It is found that promising magneto-dielectric materials,with close values of real permeability and permittivity over 30-90 MHz(VHF),can be obtained for the samples at Zn concentrations between x=0.05 and x=0.10.

Bandwidth Enhancement of RMPA Using 2 Segment Labyrinth Metamaterial at THz

The past few years have been very eventful with respect to the evolution of the concept and implementation of “left-handed materials (LHMs)”. This paper elucidates antenna parameter optimization using 2 Segment Labyrinth metamaterial embedded in antenna substrate at high frequency (THz). Ansoft HFSS has been used to design and analyse the RMPA (rectangular microstrip patch antenna) with design frequency 9.55 THz and operating range of 8.55 THz to 10.55 THz having RT Duroid (εr = 2.33) as substrate material. Magnetic properties of labyrinth resonator have been used to mathematically demonstrate the negative refraction. Nicolson Ross Wier (NRW) method has been used to retrieve the material parameters from transmission and reflection coefficient. Upon incorporation, bandwidth widens to around 4% and VSWR improves by approx 1.5%.

光电导天线材料对辐射太赫兹波特性的模拟分析

光电导天线是太赫兹时域光谱系统中普遍使用的宽带太赫兹辐射源,天线衬底材料对其辐射太赫兹波特性至关重要。目前广泛使用的光电导天线材料是第二代半导体材料GaAs,而第三代半导体材料具有更大的禁带宽度,对提高天线辐射太赫兹波的功率更有利。本文利用大孔径光电导天线的电流瞬冲模型,对常用光电导天线材料(SI-GaAs、LT-GaAs)和未来有望应用于光电导天线的第三代半导体材料(ZnSe、GaN、SiC)辐射太赫兹波的特性进行了仿真研究,结果表明在相同偏置电场和各自最高光通量触发下,LT-GaAs天线辐射太赫兹波的幅值最高、频谱最宽;第三代半导体材料制备的天线可以承受更高的偏置电场,在各自的最大偏置电场下辐射太赫兹波的强度远远大于GaAs天线。本工作对研制新型的第三代半导体光电导天线提供了理论指导。

声波式机械天线的谐振频率调控方法

声波式机械天线作为机械天线的重要类型之一,其谐振频率与固有频率高度耦合,而目前声波式机械天线受到材料尺寸限制,谐振频率较高,无法满足甚低频或更低频段的需求。为调控声波式机械天线的谐振频率,对声波式机械天线进行了振动建模,提出了增加单边固定约束、增加自由端质量和去除天线部分材料三种方法,并通过有限元仿真对所提方法进行了验证。结果表明,三种方法均能有效调控声波式机械天线的谐振频率,且与解析模型具有良好的一致性。通过应力分布研究了三种调控谐振频率方法对天线辐射的电场强度或磁场强度的影响,对声波式机械天线的设计具有重要参考意义。

空间柔性阵列天线薄膜阵面制造技术研究

简要阐述了空间柔性天线的进展,分析了空间柔性天线薄膜阵面制造关键技术。研究了薄膜阵面电磁波传输金属薄膜制备技术、薄膜阵面图形化制造技术、薄膜阵面拼接用材料评价、薄膜阵面的裁切技术等。采用磁控溅射技术,通过溅射功率、走带张力、走带速度的调节,在有机柔性薄膜基材上镀制了不同厚度的金属铜膜,实现了有机柔性薄膜基材的表面金属化;利用飞秒激光刻蚀精度高,不损伤柔性薄膜基材的特点,获得了图形化的金属薄膜阵面单元;对3M92号胶带与改性聚酰亚胺胶接材料的拼接强度与耐高低温性能进行了试验对比,发现改性聚酰亚胺胶接材料的强度与耐高低温性能更好,更适合薄膜阵面的拼接;对比了用纳秒激光和飞秒激光裁切的薄膜微观形貌,结果表明,用飞秒激光裁切的切面光滑,无烧蚀与毛刺,适合于高精度薄膜阵面的制造。研究为空间柔性阵列薄膜天线的制造提供了大量的基础数据。

一种超宽带双陷波可穿戴天线设计

基于牛仔布柔性材料,设计了一种小型化双陷波超宽带可穿戴天线。天线由牛仔布料基板、开槽单极子辐射贴片和缺陷地平面构成,具有超宽带特性,能覆盖3.1~10.6GHz的超宽带频段范围。通过在天线接地板刻蚀两条新型蜿蜒形槽和在单极子辐射贴片上添加对称枝节以实现双陷波特性。该天线结构紧凑,尺寸仅为24mm×28mm×0.84mm。仿真的-10dB天线工作带宽为143.7%(2.95~18GHz),并且天线在3.24~3.87GHz和5.11~5.91GHz频段内具有双陷波特性,能有效抑制全球微波互联接入系统(WiMAX)和无线局域网(WLAN)频段的干扰。此外,对天线的可弯曲性、辐射性能以及人体安全性能进行了分析。测试与仿真结果基本一致,表明该天线可用于可穿戴系统中。

一种基于柔性材料的可穿戴式天线设计

针对传统杆状天线在现代化战争应用场景中存在的带宽窄、质地硬以及隐蔽性与便携性较差等问题,提出了一种基于柔性介质材料的可穿戴式天线,该天线采用平面单极子天线的形式,极大地降低天线的剖面。借助电磁仿真软件CST Studio Suite 2023进行仿真分析,该天线尺寸为270 mm×270 mm×1.1 mm,重量仅有120 g,包含0.37~1.8 GHz的实测宽带频段,在人体加载影响下,实测频段范围超过0.3~1.8 GHz。给出了反射系数S_(11)、辐射方向图的结果,分析了人体对天线的影响,结合通信电台开展实物对比测试。仿真与实测表明,可穿戴式天线在士兵手持电台中具有一定的应用前景。

Mechanically scanned leaky-wave antenna based on a topological one-way waveguide

We propose a uniform backfire-to-endfire leaky-wave antenna(LWA)based on a topological one-way waveguide under external bias magnetic field.We systematically analyze the dispersion,showing that the proposed structure supports leaky mode arisen from total internal reflection.By means of tuning frequency or magnetic field,we obtain fixed-bias frequency and fixed-frequency bias LWA with continuous beam scanning from backward,broadside to forward direction.More importantly,we,for the first time,demonstrate that this proposed LWA shows mechanical tunability,allowing us to manipulate the radiation direction from backward,broadside to forward direction by mechanically tuning the air layer thickness.The simulated results show that our system exhibits super low 3dB beam width,high radiation efficiency as well as high antenna gain.Being provided such multiple controlled(especially mechanically)beam scanning manners,the present LWA paves an advanced approach for continuous beam scanning,holding a great potential for applications in modern communication and radar system.

晶圆级树脂基低成本W波段封装天线微系统

面向W波段探测与通信系统的小型化、低成本应用需求,本文采用晶圆级树脂基扇出型封装工艺,通过对有源封装天线集成架构、互连传输结构和天线阵列进行设计与仿真,设计了一款工作频率为94 GHz的封装天线微系统。该封装天线微系统集成了4×4磁电偶极子阵列天线和16通道幅相多功能射频芯片。通过Ansys HFSS全波仿真,系统波束扫描范围在E面≥±30°,H面≥±40°,在7.1 mm×8.3 mm×1.2 mm封装尺寸内实现了封装天线等效全向辐射功率≥39.1 dBm。该封装天线微系统具备规模扩展能力,可广泛应用于探测、通信以及安检等领域。

碳纤维复合材料天线框架竖直状态加工工艺研究

天线阵面的平面度是与天线性能相关的最重要的技术指标,为了达到安装要求,介绍了碳纤维复合材料天线框架的结构特点、使用要求和制造技术难点,研究并分析了重力对框架平面度及其稳定性的影响,提出了竖直状态补偿、平放状态加工的机加工方案,进行了天线框架消除重力影响状态下加工的验证试验。试验结果表明,按此方案加工的天线框架在竖直悬挂状态下的有源安装面和波导安装面平面度均达标,满足天线框架地面展开试验及在轨失重状态下的使用要求。

一种基于磁性材料的小型化高隔离MIMO天线

本文提出了一种采用加载地板枝节实现高隔离的双频八单元MIMO天线。通过采用紧凑的IFA天线组成的天线单元,能够分别在2.60 GHz和3.55 GHz处产生良好的谐振,为了减小天线单元之间的相互耦合,在两天线单元之间引入“T”型地板枝节,使得所提出的MIMO天线在两个工作频带上实现了20.8 dB和25 dB的隔离。此外,为了实现MIMO天线阵列小型化,通过在地板枝节基板加载磁性材料,利用磁性材料的高介电常数和高磁导率实现地板枝节小型化,同时在较大范围内减小两天线单元之间的间距,仿真结果表明在MIMO天线的两个工作频带上依然能够实现较高的隔离,从而满足MIMO天线阵列小型化的需求。

小型化MIMO天线设计在增强型移动宽带中的应用分析

根据无线通信技术快速发展的需求,针对性提出小型化多输入多输出(Multiple Input Multiple Output,MIMO)天线的设计,阐述在紧凑空间内实现多个天线元素布局的原理与技术挑战,评估小型化MIMO天线在增强型移动宽带应用中的性能。通过采用先进的隔离技术、优化辐射效率及带宽性能的方法,提高无线通信系统效率,并扩大系统容量。此外,介绍多频带操作和智能可重构天线技术在提升网络性能方面的应用,展示小型化MIMO天线在现代通信网络中的关键作用。

Bi-BASED HIGH T_c SUPERCONDUCTING LOOP ANTENNA

INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials began to be utilized in fabricating antennas since 1960s. In 1988, the Birmingham group of UK made for the first time the small dipole antennas