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1.
设计了一种新型单臂螺旋边馈阶梯喇叭圆极化背腔天线,天线单元由阶梯喇叭、单臂螺旋及圆形背腔组成.单臂螺旋采用准空气同轴线激励,给出了天线单元的轴比、驻波、方向图宽频带特性.提出单元旋转反相馈电方法改善了天线子阵轴比和极化隔离,同时解决了馈电空间狭小的难题.对阵列进行了加工测试,测试与仿真结果吻合.结果显示,天线增益、驻波带宽、轴比带宽和方向图性能优良,此种天线具有很好的工程应用前景.  相似文献   

2.
研究了一种等弧距单臂半球柱面螺旋天线,其具有宽带、小尺寸、圆极化、低剖面等特点.该天线采用半球柱面螺旋天线结构,通过在馈电端引入等效L节匹配网络进行阻抗变换,扩展天线带宽,最终实现了天线的小型化、圆极化及超宽带.利用HFSS仿真软件对半球柱面螺旋天线结构参数进行优化,仿真及测试结果表明,该天线具有超过30%的阻抗带宽及超过20%的轴比带宽,最高增益能够达到9 dB,具有良好的辐射特性.  相似文献   

3.
本文设计了一种应用于卫星定位系统的微带天线,具有较大的波束宽度和较好的圆极化特性.该天线采用了接地板开槽的微带天线和角锥喇叭结构:在接地板上开槽引入几何微扰,实现了圆极化;将接地板开槽的微带天线安置于角锥喇叭之上,达到了展宽波束的目的.仿真结果表明,该天线在E面和H面形成了宽波束,E面波束宽度大于123°,H面波束宽度大于136°,而且在波束范围内都有很好的圆极化特性.  相似文献   

4.
一种实用新型宽波束圆极化天线   总被引:1,自引:0,他引:1  
杨小龙 《微波学报》2010,26(Z1):198-200
圆极化天线是一种应用非常广泛的天线形式,尤其是在卫星通信和卫星定位设备中,随着这些系统的发展,对天线提出了越来越高的要求,低剖面、宽波束覆盖的圆极化天线越来越受到追捧,本文提出了一种新型宽波束圆极化天线—双臂螺旋天线,该天线3dB 波束宽度可达160°以上,具有结构简单、尺寸小、性能稳定等优点,可以广泛应用于各种军用、民用通信领域。  相似文献   

5.
研究了一种具有良好工作性能的微带-喇叭组合右旋圆极化天线,首先设计了一种双层宽带圆极化微带天线结构,同时满足电压驻波比(VSWR)≤2,轴比(AR)≤4 dB的频带宽度(Bw)≥24%,主极化增益大于9 dBi;通过引入角锥喇叭结构,在工作频带内将天线增益提高到12 dBi以上,同时不影响原天线的其他性能。为更好了解微带-喇叭组合右旋圆极化天线的性能,并快速而准确地设计该天线结构,对天线主要几何参数进行了适当分析和研究。  相似文献   

6.
在卫星收发系统中,圆极化天线是一种重要的器件,负责信号的接收和发送。而径向线螺旋天线是一种重要的圆极化天线,但为实现圆极化性能,天线高度需达到0.15λ。通过引入主径向线和副径向线之间的耦合,减小了天线的高度,从而实现了低剖面的径向线螺旋天线。通过在馈电结构中引入贴片电容,从而改善了天线的阻抗匹配性能。所提出的径向线螺旋天线的高度为0.0525λ,仅为传统径向线螺旋天线高度的34%。为验证理论预期的可实现性,设计了基板为FR4、中心频率在1.54 GHz的低剖面径向线螺旋天线。实验结果表明,该天线的实测10-d B匹配带宽和3-d B轴比带宽分别为900 MHz和27 MHz,实测增益在2.9 d Bi,能够满足卫星接收天线的收发要求。  相似文献   

7.
一种新型双频宽波束四臂螺旋天线的设计   总被引:1,自引:0,他引:1  
根据移动卫星通信和卫星导航定位中对天线宽波束、圆极化和低仰角增益等要求,设计了一种新型的双频四臂螺旋天线,通过将工作于不同频段的两副结构类似的天线以内外共轴的方式形成一个整体来实现双频工作。天线通过开槽线巴伦实现平衡馈电,利用四臂螺旋自身的结构特点构造了90°自相移结构,获得了较好的宽波束圆极化特性。测试结果表明。实测和仿真结果基本一致,天线在两个频段都实现了较好的宽波束圆极化特性。  相似文献   

8.
文章介绍了四臂螺旋天线的结构特性和几何尺寸、螺旋模式;设计了一种小型四臂螺旋天线,采用巴伦平衡结构的自相移馈电方式馈电,将螺旋臂印刷在高介电常数陶瓷柱上,减小了天线的体积,通过仿真分析,该种天线具有良好的宽波束和圆极化特性。  相似文献   

9.
无源雷达导引头一般采用宽带天线以满足对空间辐射源的探测和跟踪。圆锥等角螺旋天线具有宽频带和圆极化的辐射性能,因此它是一种合适的无源雷达导引头天线实现方案。为了满足实际项目的需要,本文开展了圆锥等角螺旋天线的设计和实验研究。设计了具体的天线结构和参数,采用微带粘结技术实现圆锥表面共形的等角螺旋天线臂的加工和焊接。设计了一种超宽带微带平衡-不平衡转换器(巴伦)以实现对设计天线的馈电。在微波暗室内对加工的天线进行了测量,给出了辐射方向图、增益、轴比等测试结果。实验结果表明,对于频带1GHz到5GHz工作频率范围,本文设计和加工的天线性能可以满足技术要求,其实验结果为本天线的实际应用奠定了基础。  相似文献   

10.
一种共形宽带圆极化螺旋天线的设计   总被引:1,自引:0,他引:1  
为满足共形天线低剖面特性的要求,设计并制作了一种低剖面的圆极化阿基米德螺旋天线.天线利用单臂阿基米德螺旋结构实现圆极化辐射,并采用同轴探针馈电.实测结果表明,天线在2~ 11.4 GHlz的频率范围内回波损耗小于-10dB,轴比小于3dB的频率范围为2.5~8.4 GHz.该天线结构简单,工作频带宽,且剖面极低,可作为...  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

17.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

18.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

19.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

20.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

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